Phelps-Dodge (also known as PD) was bought by Celwave (year?), which was bought by Radio
Frequency Systems (aka RFS) (year?) whose web site is at
http://www.rfsworld.com/RFSGlobal.
If you are looking for other web pages containing information on a specific antenna - for
example some repeater group whose web page mentions a Phelps-DodgePD-458 in passing - you
may have to check under all three company names.
For example, under Google, you would type (less the square brackets): [ "PhelpsDodge"
OR Celwave OR "Radio Frequency Systems" OR "RFS" 458 ]. Note that the OR parameter in
a Google search must be in ALL CAPS.
MFJ bought Hy-gain in May of 1999. Then they purchased Cushcraft in August of the same year.
Antenna Specialists was sold to PCTel (year?) - and their corporate web site is at
http://www.antenna.com, and the product web site
is at http://www.antenna.com/products.html.
The 2-way mobile product model number lookup page is at
http://www.antenna.com/lm_cat/index.html.
I was told recently that PCTel bought both Maxrad and Antennex (but I don't know the dates).
DB Products was bought by Andrew, but they didn't want everything. The leftovers (including
duplexers) are now sold by a company called dbSpectra, located in Lewisville, Texas (the web site
is at http://www.dbspectra.com). From their web site: "...in
December of 2004, dbSpectra signed a licensing agreement with Andrew Corporation to manufacture
and sell the Legacy Decibel Products site management equipment such as filters, duplexers,
combiners, tower top amplifiers and more. These products had been outsourced and dbSpectra
successfully brought them back and have since hired many of the personnel involved
in the design and manufacture of these excellent products."
In March of 2006 the Laird Group of England (AKA LairdTech) purchased Antenex for about
$20.5 million, and then in Febuary of 2007 bought Cushcraft for about $90 million.
And about a month later Andrew purchased the English manufacturer Precision Antennas for
about $36 million.
In December of 2007 Andrew was bought by CommScope for US$2.6 Billion.
Here's the
current Andrew/Commscope catalog.
In many cases you will find that manufacturers web sites have theoretical information that
is applicable to all... i.e. the theory articles on Manufacturer "X" products applies to
Manufacturer "Y" and to "Z". Sometimes researching other manufacturers web sites can save you
a lot of money... for example, if Manufacturer "X" claims that a crystal filter will solve
your desense problem. Then you go to "Y"s web site and there you discover that, yes, a crystal
filter can be used in the receiver feedline to notch out a local signal, or to pass your signal.
What the Manufacturer "X" web site didn't tell you, and the Manufacturer "Y " or "Z" web site
did, is that in your specific case it may not work. Unless you were familiar with crystal
filters you would not know that the insertion loss can be as high as 12db, which in many cases
makes a crystal filter on a repeater receiver unusable.... the signal level budget just isn't
there (i.e. while adding the crystal filter would kill the interfering signal, it also reduced
your receiving range to 1/2 of what it was, or maybe even less). So do your homework and learn
all you can about the theory behind the hardware before you hand over your money.
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Introductory Information for System Engineering
READ THIS FIRST |
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Getting the most from your repeater system
By Kevin Custer W3KKC |
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RF Communications - A Non Technical
Approach 1.47 MB PDF By Decibel Products Corp.
Many years ago Decibel Products
(a major RF hardware manufacturer) published a series of informative pamphlets on systems
engineering topics. The earliest seems to be 1964. The topics included Base Station
Antennas, Combiners, Selective Cavities, Duplexers, RF Transmission Lines and Lightning.
All five pamphlets were recently combined into a single PDF document titled
"RF Communications - A Non-Technical Approach". DB made it available on their corporate
web site, and now it's available from Andrew/CommScope
at their web site
or as a local copy here. This document
should be required reading for anyone wanting to learn about antenna systems. (Thanks
to Duane Hall KA8GVH for the pointer.) |
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TX-RX Tech Aid #77001 Some very useful
charts and procedures. Worth printing and adding to your tech notebook. By TX-RX Corp. |
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Help!! My repeater seems deaf By Kevin K. Custer W3KKC |
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Repeater
Sensitivity De-sense Testing 325 KB PDF by Jacques Audet VE2AZX
An excellent writeup that explains the techniques plus shows how to build a high-isolation
signal sampler. |
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Receiver
desense testing By Karl Shoemaker AK2O of the Spokane Repeater Group
(Original offsite link at the SRG web site) |
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Is a 3 dB change in power really worth it? The
answer is "It Depends" By Neil Johnson WBØEMU
If you are in charge of maintaining a repeater system, or building a new one, then this is worth reading. |
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Some thoughts on Repeater
Receiver-to-Transmitter Isolation By Mike Morris WA6ILQ |
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Guidelines for mounting antennas on
towers 71 kB PDF. A scan of a guidelines page covering tower-to-antenna distances - donated
by Skipp |
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ANTPLOT - A Side-Tower Mounted Antenna Pattern Prediction
Program This is a Zip file of both version 5.3 and of version 5.4 of the DOS
program originally provided by Antenna Specialists. It's noted as being "Program No. 3 of the
Antenna Specialists RF TOOLS Series". Also called "tplot" for some reason. Donated by A. Nony Mous
Does anyone have Program #1, #2 and any others? |
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Recommended Coax and Connectors for
the iDEN Enhanced Base Transceiver System 24 kB PDF. Motorola Engineering wrote this
three page discussion of cable and connector types with regard to combining, intermodulation, and
other RF performace factors. They concluded that LMR-nnn and LMR-nnnn series cable is
specifically NOT recommended in any radio site RF environments, especially duplex environments
(where NNN is any 3-digit number and NNNN is any 4 digit number). While iDEN is (was?) a 900 MHz
system the physics are the same at 28 MHz through 1296 MHz. Well worth reading. |
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HELIAX Coaxial Cable for Low Intermodulation
Generation 21 kB PDF. Andrew Engineering wrote this one page writeup on why foil-braid
cable causes intermod. Despite the fact that you'd expect that conclusion from the makers of
Heliax there's a lot less sales pitch and a lot more engineering presented than you'd think.
Worth reading. |
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Where exactly is your repeater? And
are you really sure? Read this before you file any paperwork and help out your local coordination
folks, and prevent an FCC or FAA citation. Donated by Eric Lemmon WB6FLY |
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MIL-STD-188-124B "Grounding, Bonding, and
Shielding for Common Long Haul/Tactical Communication Systems including Ground Based
Communications-Electronics Facilities and Equipments" 3.8 MB PDF file
dated 01-Feb-92
This is the newer military handbook on grounding, and is a
quicker read at about 40 pages, however it says on the second page of the forward that "This
Standard is further implemented by MIL-HDBK-419", listed below. This handbook is
approved for public release and distribution is unlimited. |
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MIL-HDBK-419A "Grounding, Bonding, and Shielding
for Electronic Equipments and Facilities" 9.6 MB PDF file dated 29-DEC-1987
This is the big military handbook on grounding. It is large, in two volumes
totaling about 812 pages. Volume one is 396 pages of theory, volume two is 394 pages of
practice. This download is the complete 2 volume set in one PDF file, and volume 2 starts
on page 419 of the PDF file. This book covers grounding for safety, lightning, nuclear blast
and most everything else. A very good read and a real eye opener. This handbook is approved
for public release and distribution is unlimited.
At one point (Feb 1999), the hardcopy (including postage) was FREE if you ordered it from:
Commanding Officer
Naval Publication and Forms Center
5801 Taylor Avenue
Philladelphia PA 19120 |
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MIL-STD-464 "Department of Defense Interface Standard
Electromagnetic Environmental Effects Requirements for Systems" 1.2 MB PDF
file dated 18-Mar-97
"This standard establishes electromagnetic environmental effects
(E3) requirements and verification criteria for airborne, sea, space, and ground
systems, including associated ordnance." This handbook is approved for public release and
distribution is unlimited.
Why, you might ask, is this one on a web page that covers antenna systems? Well,
"electromagnetic environmental effects" includes lightning. And lightning can have
seriously negative effects on antenna systems (and the radios they are connected to). |
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More lightning info is
here (off-site link), on the IEEE web site, including several links to other excellent
IEEE articles.
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High power amplifiers and duplex radio Tubes vs.
Transistors, By Kevin Custer W3KKC Short version: at high power levels tubes
win. |
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Is this connector any good? An article on the
perils of cheap connectors by Jeff DePolo WN3A |
|
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EMR Corp. Technical Papers Index An
index of downloadable PDF papers on Isolators, Duplexer retuning, Ferrite and Hybrid Combiners,
Multicouplers, Preselectors, Bandpass and Pass-Notch Cavity Resonators. |
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Using Preamps with repeaters... and why sometimes
you wouldn't want to... by Mark Malm NØFAZ and Kevin K. Custer W3KKC |
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The Effects of Trees
on Slant Propagation Paths 1.3 MB PDF By Vogel Hagn. This is an academic
paper that will be of special interest to UHF, 900 & 1200 MHz system owners. |
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Best Practices Guide 49 kB
PDF By Motorola Inc. This is a write up on solving interference problems at 800 MHz and
oriented towards Public Safety communications, but it's worth reading by any repeater
owner or builder. |
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Interference Technical
Appendix 682 kB PDF By Motorola Inc. This is intended to be an add-on to
the "Best Practices Guide" above. Also very worth reading. |
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Calculating Your Radio Horizon By A. Nony Mous |
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Radio Mobile Coverage
prediction software by Roger Coudé VE2DBE A bit of a learning curve,
but darn good stuff (offsite link)
A Yahoo group supporting it is at
http://groups.yahoo.com/group/Radio_Mobile_Deluxe
If anybody wants to put together a "Getting Started" article, we'll make
room for it here. |
 |
The calcualtors, especially Dale Bickels HAAT, Coordinate and Distance calculators are
useful. Scroll down to the Calculators section for them.
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Introductory Information on Cavities, Diplexers,
and Duplexers
READ THIS FIRST
If you're just starting out, I strongly suggest that you read the above article, then first nine
articles in this section, especially those by Jacques Audet VE2AZX, John Portune W6NBC and by
William F. Lieske. Yes, there is some repeated material between the articles, but if you're new
to duplexers, it won't hurt. The 9 articles collectively will give you a basic and solid education
on duplexers. |
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DUPLEXERS - An Introductory
Tutorial by Jack Daniel KD6YVL (offsite link)
This is a nice writeup that should be titled "Duplexers 101". Well worth reading. |
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Theory and Testing of
Duplexers 1.4 MB PDF by Jacques Audet VE2AZX
This is a large (60 pages) technical writeup that should be titled "Duplexers 102". Again,
well worth reading. |
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Technical Duplexer Page with
good theory and explanations, and some homebrew construction notes. By John Portune W6NBC |
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Understanding,
Maintaining & Re-Tuning Antenna Duplexers 145 KB PDF By William F. Lieske, Sr., Founder
of EMR Corporation
A good basic theory writeup, including the differences between Band Pass and Band
Reject. The
original copy at the EMR web site |
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Combating
Spurious Output And Overloading With Cavity Filters 1.2mb PDF by TX-RX Corp.
A "Seminar Series" writeup that covers the theory behind cavity filters - mandatory reading for those
unfamiliar with them. |
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Coaxial
Resonators, Applied theory and practice, with photos by Mike Pinfold ZL1BTB (offsite link) |
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Duplexer Theory and Tuning
351 KB PDF by Dave Metz WAØAUQ
An overview of duplexers from an amateurs point of view, with some good hands-on info and some photos
of a good home-brew duplexer. |
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Why are there quarter-wave coax cables
between my duplexer's cavities? Gary Schafer K4FMX
This article also explains why the fully-cabled duplexer provides more notch depth than the sum
of the separate sections. |
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Interference
Control Through The Use Of Cavity Filters And Ferrite Isolators 900 KB PDF by
TX-RX Corp. |
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Technical
Notes on Duplexer Problems and Remedies 1mb PDF By TX-RX Corp. |
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The Design of High Isolation
Duplexers and A New Antenna for Duplex Systems 772 KB PDF
An IEEE Transactions publication from March 1965 by W. B. Bryson of Communications Products Company, a
division of Phelps Dodge. |
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A Guide to Duplexer Specifications over 130
different models, by Paul Kelley N1BUG (Contributions to the list are very welcome) |
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Tuning
and Adjusting Vari-Notch-Duplexers 185 KB PDF by TX-RX Corp.
A "Seminar Series" writeup that covers the theory behind cavity filters and isolators. |
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T-Pass
Expandable Cavity Muticoupler System 500 KB PDF by TX-RX Corp.
A "Seminar Series" writeup that covers the various type of cavity-based multicouplers and the
T-Pass design. |
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The Hybrid Ring Duplexer A
comprehensive explanation of the Hybrid Ring, by Kevin Custer W3KKC |
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Six Meter Heliax Duplexer
Design by Jim Poll WB5WPA (off-site link that is no longer available)
Here's one implementation of the above design
by Oscar Quintanilla KF6YB (off-site link)
Here's
another implementation of the above design by Mike Perryman K5JMP (off-site link)
Six Meter Heliax Receive Filter Construction and Testing article
based on the above designs, by Robert Meister WA1MIK and David Malicki N1OFJ. Note that this is NOT a
full duplexer; just the receive half (but it could easily be extended to a full duplexer).
Yet another implementation of a six meter filter by Tim
Ahrens W5FN
Another Heliax notch filter, but for two meters by
Jeff Otterson N1KDO. |
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Some Tests on Duplexer
Loops 233 KB PDF by Jacques Audet VE2AZX
Some interesting observations, including scope traces. |
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Using
open stubs to notch interference By Nico PAØNHC (offsite link)
An excellent article on reducing paging transmitter (and others) interference into 2m repeaters.
Note that common European usage is that a comma is used where Westerners usea period to mark decimals,
for example 144.550 MHz is written as 144,550 MHz so readers used to the period will have to do
some mental "translation". In this article Nico has used a mix of both forms so it can be a
little confusing on the first read. |
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GE Datafile Bulletin 10002-1, A
25-250 MC Quarter Wave Stub Filter General Electric produced several useful RF engineering
DataFile Bulletins (the ones we have are available for free download from
the GE LBI page at this web site). This one is a 400 KB PDF
file, and is subtitled:
"Even though General Electric Two Way Radio Transmitters well exceed FCC requirements for spurious
radiation, the 60-80-dB sprious attenuation provided may, in a few situations, be insufficicient to
provent interference. This bulletin describes the construction of a filter, useful for supressing
spurious radiation at one specific frequency..." |
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Someone say 6 meter duplexer? A
comprehensive conversion of a lowband pass cavity to BpBr by Jeff DePolo WN3A... |
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How do I tune this notch duplexer?
by Kevin Custer W3KKC |
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Tests of the DCI VHF and UHF 4-pole bandpass
filters by Robert W. Meister WA1MIK
These filters definitely do the job, meeting or exceeding manufacturer's specs. They cover the entire
144-148 and 440-450 MHz bands and have sharp cutoffs. If you need more filtering, they also sell
6, 8, and 10-pole filters with attenuations over 80dB. These handle 200 watts and can be used at
repeater sites. |
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A Homemade Duplexer for 2-Meter Repeaters
3.1 MB PDF By John Bilodeau, W1GAN (from the July 1972 QST magazine)
Note: In the 35-plus years since this article was written, the spring-contact based BNC has fallen out
of favor. Type N connectors (and to a lesser extent the TNC connector) are much preferred over BNC
connectors as they depend on a silver-to-silver screw compression contact, plus they can handle more
power. You must use double shielded coax in the harness. RG-55 is mentioned in the
article, but I'd use RG-400 and compensate on the inter-cavity lengths. If anybody has built this
unit with better connectors and modern cable, and would like to update this article please do so, then
write an article we can put here. |
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Speaking of home-made cavities...
114 kB PDF. This writeup shows what can be accomplished with aluminum beer barrels. |
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Speaking of home-made
duplexers... This photo shows what can be accomplished with old fire extinguishers. |
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Garbage In, No Garbage
Out 2.5 MB PDF file By John E. Portune, W6NBC from the July 1996 issue of 73 Magazine.
John needed a cavity to protect his 137 MHz weather satelite receiver system from local grunge - and
discovered that a common metal garbage can made a good starting point. |
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Homebrew Diplexer Design Notes
22 KB PDF file by unknown.
Some hand-written design notes for making a simple 144/440 MHz diplexer. |
Decibel Products Click here for DB antennas
Note that Decibel Products ("DB") and Phelps Dodge ("PD") used similar model numbers at times. A DB-506
is very different from a PD506... |
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Data Sheet on DB's line of power dividers - Three
page 268 KB PDF file donated by John Lock KFØM
This writeup covers the K522 & K542 for 144-174 MHz, the K526 & K546 for 406-512 MHz, the K528 & K548
for 800-960 MHz and the K528M & K548M for 1850-1990 MHz |
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DB's pipe and tower mounting clamp kit DB-365-OS Early
version donated by John Lock KFØM |
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DB's pipe and tower mounting clamp kit DB-365-OS &
ASPR616 165 KB PDF file (later version) |
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Catalog page
for early model DB-4002 band pass cavities 3.5 MB PDF file
The 4002 cavity covers multiple ranges, the cavity is the same, the differences are in the loops.
A=118-148 MHz, B=144-174 MHz, C=406-420 MHz, D=450-512 MHz. |
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Installation
and Tuning Instructions for DB Band Pass Cavity Filters 50 KB PDF file
This information is pretty generic despite the models listed: DB-4001 (148-174 MHz),
DB-4002 (118-512 MHz), DB-4011 (70-88 MHz), DB-4013 (88-118 MHz), DB-4015 (118-148 MHz),
DB-4020 (406-420 MHz), DB-4018 (225-400 MHz), DB-4021 (406-512 MHz), DB-4026 (406-512 MHz),
DB-4028 (806-960 MHz), DB-4042 (30-50 MHz), DB-4170 (138-174 MHz), DB-4171 (450-512 MHz). |
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Tuning Instructions
for the DB-4022 (UHF) & 4029 (800 MHz) band pass / band reject cavities 32 KB PDF file |
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DB-4023 UHF duplexer (3 cavity) and 4081 (4 cavity) spec sheet
donated by W. M. Kahl N6KYD |
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Tuning Instructions for the DB-4030 (four cavity) and
4032 (six cavity) Low Band Duplexers five page 920 KB PDF donated by W. M. Kahl N6KYD
Tuning Instructions for the DB-4030
and 4032 4-cavity and 6-cavity Low Band Duplexers 24 KB PDF file (appears
to be a later version of the five page one above)
Converting the DB-4032 Low Band Duplexer to the 6M Amateur
Band 29 KB image A one-page writeup from DB Engineering on converting the
DB-4032 to the6-meter amateur band. It's a scan of a fax so it's not perfect, but it's quite
readable (oriented for printing)
Same drawing sized to be printed on 11x17 paper
Both donated by Chris Nicholson N9LLO |
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Installation and
Alignment Instructions for the DB-4036 (mid-band), 4044 and 4046 (high-band) Base Station
Duplexers 48 KB PDF file
A two-page PDF file describing wide-spaced (3 MHz and 5 MHz) duplexers that are not of much use
to hams, but would be to public safety and disaster services folks. |
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DB-4042 Resonant Filter Modifications An
offsite link to KB6MIP's Technical Information Page articles. |
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DB-4048 duplexer specs (high band - 146-174 MHz) - an eight
page 1.22 MB PDF file
DB-4048
duplexer review article from June 1975 QST magazine -
Page 1
Page 2
Scan courtesy of Glenn Little WB4UIV |
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Modifying/Improving the DB-4048 Notch Cavity Duplexer
By Ralph Hogan W4XE |
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Installation and Tuning
Instructions for the DB-4055 & 4056 (high band), 4067 & 4068 (406-420 UHF) and 4071
& 4072 (450-470 UHF) duplexers 40 KB A two-page 41 KB PDF file
Here's a photo of the internals
of a 4072 housing. |
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Installation and Tuning on
Decibel Products 4057 (three cavity) and 4058 (four cavity) high band duplexers Two page
123 KB PDF donated by A. Nony Mous |
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Catalog sheet on the DB-4060 & 4062 Band Pass/Band
Reject duplexers 55 KB PDF file
Installation and Tuning Instructions for the DB-4060
& 4062 Band Pass / Band Reject duplexers 46 KB PDF file (the DB-4060
has 4 cavities, the 4062 has 6 cavities)
Repair of the DB-4060 & 4062 Band Pass / Band Reject
duplexers 344 KB An article by Bernie K5BP detailing notch capacitor replacement for
these units, including a source for the original component.
Repair of the DB-4060 & 4062 Band Pass/Band
Reject duplexers An offsite web page by N1BUG... he writes:
I have a DB-4062, which is the 6 cavity version of the 4060. It was old when I placed it in service
in 1997 but worked OK. Over the years it just slowly deteriorated until it became essentially unusable.
Finally I took the thing apart to investigate, and was able to restore it to excellent function after
15-20 hours of work. I created a web page that covered my experience...
Specifications and Data on the DB-4075 and DB-4076 UHF
Bandpass Reject duplexers 423 KB PDF file Photo
Wiring Diagram for the DB-4076 UHF
Bandpass Reject duplexer shown in the above photo 28 KB PDF file |
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Tuning and Installation Information on the DB-4075 and
DB-4076 UHF Bandpass Reject duplexers 91 KB PDF file |
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Tuning Information on the DB-4090 806-960 MHz
Bandpass Reject duplexers 44 KB PDF file |
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Installation and Tuning
Instructions for the DB-4104 (low band), 4040 (high band) and4075 (UHF) single-cavity notch
filters 25 KB PDF file |
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Installation and
Tuning Instructions for the 4307, 4308 and 4309 Hybrid Couplers 14 KB PDF file |
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Installation
and Tuning Instructions for the DB-4318H-2C Single Channel Filter and Isolator 10 KB
PDF file describing a 164-168.5 MHz unit but the directions apply to similar units. |
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PD-506 manual 263 KB PDF Donated by
Allan Crites WA9ZZU, scanned by Eric Lemmon WB6FLY
NOTE: You CANNOT tell from the model number if a PD-506 is for 144-174 or for 220-225 MHz ! You
have to look at the frequency label !
This is a 4-cavity pass-notch duplexer than is supplied as either a 144-174 or 220-225 MHz version.
At high band it will work from 600 KHz to 7 MHz separation, and at 220 it will work at from 1 to 5
MHz separation. Rejection is specified at 80 dB, and under 2 dB insertion loss. |
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PD-506 duplexer manual 75 KB PDF Donated
by A. Nony Mous, cleaned and PDF'd by Bob Meister WA1MIK |
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Phelps-Dodge 522-509 manual 1.1
MB PDF Donated by Bill Hudson W6CBS
The manual says Celwave as they bought Phelps-Dodge, and this particular manual was printed after
the purchase.
Does anyone have the factory spec sheet or catalog sheet, the tuning instructions or can supply a
couple of photos? |
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PD-526-509 manual 492
kB PDF UHF pass/reject duplexer courtesy of Joe Szczech K1IKE.
Photo 1
Photo 2
Eric Lemmon WB6FLY wrote: This is a 6 Cavity UHF Repeater and Base Station Duplexer that is an
outstanding performer.
Specs:
Frequency Coverage = 435 to 470 MHz.
Minimum Frequency Spacing = 3 MHz.
Minimum TX to RX Isolation = 100 dB
Maximum Insertion Loss = 1.0 dB
TX Bandwidth = 0.025 MHz.
RX Bandwidth = 0.025 MHz.
Maximum Power Input = 250 watts
Connectors = "N" Female
Maximum VSWR (50 ohms) = 1.3:1
This duplexer is also sold by Motorola as part number 0185417U05, which has a current (mid 2009)
dealer price of $ 1,173.00. It is made for Motorola by RFS/Celwave, which sells the same unit as
PD526-4-2. It is the X182AD Option for Quantar, Quantro, and MTR2000 stations. I have an identical
unit in service on a 100 watt UHF MTR2000 repeater, and it is an excellent performer. Prior to
installation, I verified that its isolation was better than the 120 dB specified- a very good
figure. |
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PD-638-509-6 manual 263 KB PDF
Donated by Allan Crites WA9ZZU, scanned by Eric Lemmon WB6FLY
This is a 6-cavity pass-notch mobile duplexer that is available as a 150-162, 162-174, 220-225,
or 471-512 MHz unit.
- 150-162 or 162-174 MHz: 150 watts, 75dB rejection, 1.2 dB insertion loss at 2 MHz spacing.
At 5 MHz the insertion loss drops to 0.7 dB.
- 220-225 MHz: 100 watts, 75dB rejection, 2 dB insertion loss at 1.6 MHz spacing.
- 470-512 MHz: 75 watts, 75dB rejection, 1.7 dB insertion loss at 3 MHz spacing. |
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PD5042-1 VHF Duplexer data from Motorola
960 KB PDF scanned by Eric Lemmon WB6FLY
Motorola relabels the Celwave model PD5042-1-50 duplexers and includes them as factory option with
VHF Quantar or MTR2000 stations. Their part numbers are 0185417U01 for the 132-146 MHz range,
0185417U02 covers 144-160 MHz, and 0185417U03 covers 158-174 MHz. |
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PD-7540, PD-7560, PD-7640, PD-7660
duplexer manual 109 KB This unit is also called the "MiniPlexer".
This is a UHF flat-pack mobile notch-only duplexer that is limited to 40 watts and comes in two
ranges: 406-435 and 435-470 MHz and in 4 can or 6-can versions (7n40=4-can, 7n60=6-can). The 4-can
version provides 50 dB rejection and 1 dB insertion loss at 5 MHz spacing, and the 6-can
version provides 75 dB and 1.3 dB. Like any notch-only duplexer, any frequency outside
the notches rides right through... Donated by A. Nony Mous.
PD-7540, PD-7560, PD-7640, PD-7660 duplexer
manual 518 Kb
This is a later verion of the same manual, with enough new information to be worth having both
versions available. Donated by Allan Crites WA9ZZU, scanned by Eric Lemmon WB6FLY. |
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P-Series Duplexer Specifications Sheet Covering the
P-1C01-G, P-1C02G, P-201G, P202G, P203G, P-301G, P-302G, P-303G models by Sinclair Corporation. |
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Sinclair Q202-G cable harness drawing
88 KB courtesy of Eric Lemmon WB6FLY
Eric wrote in an email: A while back I set up a Q-202G duplexer for a local radio club. The duplexer
was originally made for and used on a commercial pair in the 152-157 MHz band, and no matter how much
work was spent on tinung the duplexer it would not perform. I had the club purchase a new low-split
harness from Sinclair. When it arrived, I took careful measurements of both the new and the old
harness, and the results are here... If the harness on your duplexer is the high-split version, with
about 12 inches between tee centers, you will never be able to achieve optimum peformance on 2m,
especially in the 145 repeater range. Some people "stretch" the cables by adding 90 degree elbow
adapters to the ends as a test, but while that works you will eventually end up buying or making a
new harness. The factory-made harness uses Delta brand crimped connectors, and is priced in the
area of $250.
Eric continued with "If I were to do this again, I would consider fabricating the harness myself,
with genuine Delta brand connectors and tees, which can be purchased for a total of around $120".
If you do, don't forget to use real mil-spec RG-214 or RG-393 coax with the silver plating (look up
"duplex noise" and "LMR-400" elsewhere at this web site). |
|
|
Tuning instructions for "P" and "Q" series cavity duplexers, and
FP, FR, FQ series cavities manual CM-1008 by Sinclair Corporation. |
|
|
Tuning instructions for the Q-202G, Q-208G, Q-218G,
2B02G, Q-2B02G, Q-2B17G series cavity duplexers manual FP-1032 by Sinclair Corporation. |
|
|
Catalog sheet and Specifications for the 6 cavity
Res-Lock Q-Circuit VHF Duplexer |
|
|
Tuning instructions for the Q-Series, ResLok
4 - Q‑circuit Duplexers - manual number CM-351.
Written on the front is "Sincl Q2330E" |
|
|
Installation and Tuning instructions for the Q‑Circuit
Res-Lock Duplexers - manual number CM-1009.
This manual covers the Q-1220E (66‑88 MHz), Q-2220E (132‑174 MHz),
Q-2222E (148‑174 MHz), Q-3220E (406‑512 MHz) and Q-4220E (806‑960 MHz)
duplexers.
Photos of a new coupling loop for a 2220E:
Photo 1
Photo 2
Photo 3
Photo 4 |
|
|
Duplexer Tuning Instructions for the R101G to R116G and
R-1C01-G, R-1C02G, R-1A01G models (manual number CM-159):
Note: This manual also covers a large number of other models in the 2H-30, 2H-37, 2H-43, 2H-66,
2H-77, H-30, H-37, H-43, H-66 and H-77 series. The actual list is on the first page. |
|
|
Modification of R101, R104, or R110 for amateur
6 meter operation (manual number CI-051). |
|
|
Hybrid Ring Duplexer Tuning Instructions
(manual CM-106) (theory on the W2EUP-designed Sinclair Hybrid Ring Duplexer). |
|
|
MR-354, MR-356 and MR-3332 406-512 MHz
mobile duplexer catalog sheet 191 KB JPG file - scan of a catalog page. |
|
|
Mobile duplexer MR-354 Specification Sheet 2-page
88 KB PDF file donated by Ted Maczulat VE7TFM |
|
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Mobile duplexer MR-356 Specification Sheet 2-page
87 KB PDF file |
|
|
MR series mobile duplexer
tuning (manual number CM-1010) 150 KB PDF
Covers the MR-254 and MR-256 (high band, 4.5-10MHz separation), MR-354 and MR-356 (UHF, 5-10MHz
separation), MR-454 and MR-456 (806-952 MHz, up to 45 MHz separation) units. Note that these
duplexers are rated at 50 watts or less. The high band units are built for either 148-160 MHz or
160-174 MHz splits, the UHF are built for either the 406-450 MHz or 440-512 MHz splits,
and the 800/900 units are built for 806-890 MHz and 928-952 MHz splits. |
|
|
SRL-101C Low band antenna information
The sheet says "30-50 MHz" but gives info on 30-90 MHz. 440 KB PDF file. |
|
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SRL-229 High band antenna information |
 |
Epoxy Procedure 167 KB PDF |
|
Base Pipe 61 KB PDF |
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Installation
Instructions 143 KB PDF |
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Mounting
Detail 92 KB PDF |
|
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"FP", "FR", "FQ" Series Bandpass Filters Product Description
Page 1 34.2 KB
Page 2 28.9 KB
Donated by Eric Lemmon WB6FLY. |
|
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"FP" Series Electrical Specs
27 KB PDF file donated by Eric Lemmon WB6FLY (undated) |
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"FR" Series Electrical Specs
31 KB PDF file donated by Eric Lemmon WB6FLY (undated) |
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"FQ" Series Electrical Specs
30 KB PDF file donated by Eric Lemmon WB6FLY (undated) |
|
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"FP" Series Tuning 61 KB PDF
file donated by Eric Lemmon WB6FLY |
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"FR"Series Tuning 68 KB PDF
file donated by Eric Lemmon WB6FLY |
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"FQ"Series Tuning 71 KB PDF
file donated by Eric Lemmon WB6FLY |
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"FP","FR", "FQ" Series Parts
23 KB PDF file donated by EricLemmon WB6FLY |
|
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"FP", "FR", "FQ" Series Tuning
48 KB PDF file donated by Eric Lemmon WB6FLY (undated) |
|
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"FP", "FR", "FQ" Series Tuning
2.64 MB PDF dated August 2010
|
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"P","Q", "R" Series Description
37 KB PDF file donated byEric Lemmon WB6FLY |
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"P" Series Electrical Specs
40 KB PDF file donated by Eric Lemmon WB6FLY |
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"Q" Series Electrical Specs
41 KB PDF file donated by Eric Lemmon WB6FLY |
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"P" and "Q" Series Preliminary
Tuning 32 KB PDF file donated by Eric Lemmon WB6FLY |
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"P" and "Q" Series Outlines 42 KB
PDF file donated by Eric Lemmon WB6FLY |
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"P" Series Retuning 58 KB PDF
file donated by Eric Lemmon WB6FLY |
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"Q" Series Tuning 86 KB PDF
file donated by Eric Lemmon WB6FLY |
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"P" and "Q" Series Parts 33 KB
PDF file donated by Eric Lemmon WB6FLY |
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"C" Series Description 53 KB
PDF file donated by Eric Lemmon WB6FLY |
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"C" Series Systems 79 KB PDF
file donated by Eric Lemmon WB6FLY |
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"C" Series Electrical Specs
59 KB PDF file donated by Eric Lemmon WB6FLY |
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"C" Series Mechanical Specs
64 KB PDF file donated by Eric Lemmon WB6FLY |
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"C" Series Curves 49 KB PDF file
donated by Eric Lemmon WB6FLY |
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"C" Series Typical Systems
67 KB PDF file donated by Eric Lemmon WB6FLY |
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"C" Series Tuning 49 KB PDF
file donated by Eric Lemmon WB6FLY |
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"C" Series Parts 71 KB PDF
file donated by Eric Lemmon WB6FLY |
| WACOM and Remec |
| WACOM started out as Waco Communications in Waco, Texas. At some point WACOM was
bought by Remec, and in November of 2001 was sold to TX-RX. |
|
Notes on the Wacom WP-641 BpBr Cavity by
Kevin Custer W3KKC |
|
Field Tuning Instructions for Remec
WP-604, WP-609, WP-612, WP-621, WP-629, WP-639 and WP-641 VHF Duplexers donated by Eric
Lemmon WB6FLY
There's one repeated error in this writeup... In Figure 1 and Figure 2 you need to terminate the
unused port with a good dummy load. |
|
Field Tuning Instructions for Wacom
WP-604, WP-609, WP-612, WP-621, WP-629, WP-639, WP-641 and WP-652 units donated by Ivan
OZ1HYG
This is an earlier version of the above file (it's from Wacom), and the instructions are a little
different. |
|
Field Tuning Instructions for Wacom
WP-678-R2 and WP-665-R2 UHF Duplexers donated by Eric Lemmon WB6FLY |
|
Spec Sheet for WP-604 (low band, 4-cavity) 371 KB PDF |
|
Spec Sheet for WP-621 and WP-641 (high band, 4-cavity)
218 KB PDF |
|
Spec Sheet for WP-623 and WP-643 (high band, 6-cavity)
178 KB PDF |
|
Spec Sheet for WP-629 and WP-639 (high band, 4-cavity)
188 KB PDF |
|
Spec Sheet for WP-652 and WP-653 (220mc, 4-cavity) 248
KB PDF This is the March 1997 version of the sheet.
The September 1985 version (no image yet) has a few differences: the older sheet says 220-300 MHz,
1.0 MHz min. spacing, 350 watts max, gray enamel finish.
The newer sheet says 210-260 MHz, 1.0 MHz min. spacing, 200 watts max, black enamel finish.
The frequency response charts look identical, as do the loss & isolation specs. |
|
Spec Sheet for WP-665 and WP-678 (UHF, 4-cavity)
215 KB PDF |
|
WP-687-3943 Catalog Sheet (900 MHz, 4-cavity)
145 KB GIF |
|
WP-687-3943 Spec Sheet (900 MHz, 4-cavity)
1.65mb PDF |
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WP-687-3943 Test Sheet (900 MHz, 4-cavity)
1.35MB PDF |
|
WP-687-3943 Field Tuning
Instructions (900 MHz, 4-cavity) 409 KB PDF |
|
WP-4941-7941 Spec Sheet (900 MHz, 2-cavity) 2MB PDF |
|
Introductory Information on Antennas READ THIS
FIRST There is a section on mobile antennas and projects towards the bottom
of this web page. |
|
Radio Antenna Engineering By
Edmund A. Laport This is a 1952 textbook and the original copyright has
expired. The PDF file is 24.5 MB. At the time, Mr. Laport was the Chief Engineer
of RCA International Division. While the book is oriented towards antennas up to
30 MHz, the Preface is worth reading (4 pages) as theory doesn't depend that
much on wavelength. The Introduction (11 pages) has some math, but it's also
very interesting. |
|
The W1GHZ Online
Microwave Antenna Book By Paul Wade W1GHZ (ex N1BWT) An excellent
text, and worth reading. (offsite link) |
|
Antenna Design for
Omnidirectional Repeater Coverage 1 MB PDF By James Ruxlow N9SN
What do you do when you need omni coverage, and you have to side mount the antenna
to a triangular tower that is over fifteen feet on each face? The Western
Illinois ARC figured it out. And their solution works well. |
| Precipitation Static and
Duplex Radio... The Phenomena and the Cure! Rain and snow
clouds contain more than rain and snow By Kevin Custer
W3KKC. |
|
Help!! I have a crackling
noise in my repeater Why it's there and how to cure it... By
Kevin Custer W3KKC. |
|
Vertical and Horizontal antenna
separation charts Provided by Kevin Custer W3KKC. |
|
Information on a Cycloid Dipole
(also known as circular polarization) antennas By the WA7X crew (offsite link) |
|
Calculating Downtilt 39 kB PDF By Scala Division
of Kathrein Corp (Technical Bulletin #112) |
|
Calculating Downtilt and Distance By Bryan K. Dorbert N3ST |
|
Side Mounted Radiation
Patterns 123 kB PDF By Scala Division of Kathrein Corp
Appears to be a scan of a page from from a catalog. |
|
Side mount antenna patterns
279 KB PDF file
A scan of a page from the "Engineering Notes" section in an old DB Products catalog |
|
Omni-Directional Gain Vertical Collinear Construction
Project By Mike Collis WA6SVT
Yes, you too can build a Stationmaster - for any frequency from 2 meters to 1.3 GHz
This writeup originally appeared in the May 1982 issue of 73 magazine, later revised in the
August 1990 issue of 73 magazine. |
|
|
Some variations and constructions ideas on the WA6SVT
collinear by Kevin Custer W3KKC |
|
|
One ham's experiences with the WA6SVT antenna by
Paul Kelly N1BUG |
|
|
Here's the construction article promised in the
above article by Paul Kelly N1BUG |
|
|
Build A 9 dB, 70cm, Collinear
Antenna From Coax By Michael Martell N1HFX (offsite link)
Yes, you can build a decent home base station antenna from RG-58 coax. |
|
|
Fiberglass Antenna Painting
Procedure 318 kB PDF By Celwave Corp. provided by Mike Dees N3EZD. See the
next article as well. |
|
Some Notes on Fiberglass Antenna Painting
Comments from several folks that accompany the above article. |
|
Retuning a Stationmaster
type antenna By Jim Barbour WD8CHL |
|
Some Notes On
Stationmaster-Type Antennas by Karl Shoemaker, AK2O of the Spokane Repeater Group
(offsite link) |
 |
There's a homebrew antenna projects section further down on this page - if anyone has something
to share just let WA6ILQ know. |
| |
Decibel Products / RFS |
 |
IMPORTANT !! A letter suffix indicates the range that an antenna is built for: 138-150
MHz, 150-160 MHz, 155-165 MHz, or 164-174 MHz but that the actual end frequencies and the assigned
letter is NOT consistent across the product line. For example, on one product (i.e. one model
number) an "A" model might be 150-159 MHz, while on another product an "A" model might be
150-155 MHz (4 MHz narrower). While in many cases an "A" range is the one that starts at 150
MHz, it can vary with EACH antenna model number: one antenna might have "A" be the 138-150 MHz range,
and another might have "E" be the 138-150 MHz range. Be very careful that you check your range letter
definition before you spend your money (on new or used antennas) ! |
|
A list of DB Products antenna models and data
68 KB PDF file compiled by Robert Meister WA1MIK in August 2012. |
|
Data sheet on the DB-201 ground plane omni antenna:
This is the so-called "bent-over" ground plane that is rated at unit gain and 500 watts.
This is a one-page version from the Allen Telecom
vintage 733 KB PDF file
It was available for any frequency from 30 MHz to 512 MHz. The ranges are: A=30-33 MHz, B=33-37
MHz, C=37-42 MHz, D=42-50 MHz, E=66-88 MHz, F=100-144 MHz, G=144-150 MHz, H=150-174 MHz, J=225-406
MHz, JJ=220-222 MHz, K=406-512 MHz, L=Uncut 30-50 MHz, M=Uncut 144-174 MHz, N=Uncut 406-512 MHz.
This is a two-page version from DB Products
166 KB PDF file dated 1995.
|
|
Cutting chart for the DB-201 Page 1 159 KB
Page 2 111 KB Allen Telecom version courtesy
of Russ Stafford W3CH
The same info in a 4 page PDF, better presented, from DB
Products 855 KB PDF file |
|
The complete cutting chart for the DB-205 coaxial
antenna 185 KB PDF file donated by Jim K1VTY, cleaned up and reduced
in size by Bob WA1MIK. The charts cover 33-174 MHz. |
|
A poor scan of the data sheet on the DB-212 side mount omni antenna (33-88 MHz)
Page 1 260 KB Page 2
203 KB Drawing of the diagram on Page 2 34kb
Here's the Andrew version of the same catalog
sheet 108 KB PDF file (a much better scan) courtesy of Allen Wilde N1IOE
and here's the DB-212
tower mounting instructions 141 KB PDF also courtesy of Allen Wilde N1IOE |
| |
You can move a low band DB-212 to 6m by basically freeing up the trombone section of the
antenna, adjusting the postion, then locking it down again. Just measure the current length of
the dipole and then multiply this length by (current-freq divided by the new-freq). So if the
current length is 184 inches and the current freq is 46 MHz and your destination frequency is
52.5 MHz the new length (in inches) is therefore 184*(46/52.5).... To change the length you will
need to remove the pop-rivet and a little dimple that the production line uses to hold the
trombone in place until the rivet is installed. Sometimes the VSWR depends on the tower face.
If you want to super tune the antenna set the antenna up on a tower leg several feet off the
ground, preferrably a little over a 1/2 wave if you can do it. Then adjust the trombone to the
length you calculated and apply a little RF power and check the reflected power. Then get a long
stick and start moving the trombone slowly while watching the reflected power. When you get the
best possible VSWR, stop and redo the rivets. Personally I'd add a bead of non-acidic silicone
bathub sealer to water-seal the joint. |
|
Detailed measured diagram of the low-band four-element
DB-212 wiring harness Courtesy Bill Cotter N4LG. |
|
WA1ZYX's web page about modifying the
DB-212 elements for 6 meters Off-site Link. |
|
Detailed harness lengths for various DB-222 multi-bay
antennas Courtesy of Paul Dumdie W9DWP. |
|
DB-224 catalog data (PDF files): Decibel DB-224
Data Sheet 154 KB PDF file Andrew
DB-224 Data Sheet 140 KB PDF file
DB-224 Instruction Sheet 158 KB PDF file
Here's the instruction sheet that comes in the box with the DB-224
Page 1 964 KB
Page 2 1,032 KB
Page 3 819 KB Courtesy John Lock KFØM.
The DB-224 is the standard antenna that all other 2m/ high band repeater antennas are
measured against. The nearest substitute for the DB-224 is the RFS Celewave 340. Both cost a
little more than a fiberglass antenna but will easily last 20-30 years, and don't have
the cracked joint duplex noise problem, nor will you have
a pile of fiberglass toothpicks on the ground after a nearby lightning strike. How many Hustler,
Comet or Diamond antennas will you go through in 20-30 years?
The DB-224 is rated at 80 MPH winds, but that's wishful thinking unless you side mount it with
clamps on BOTH the top AND the bottom. Frankly, chosing to mount your antenna on the tower top
only to get a few extra feet isn't worth a bent or broken metal support tube, and if your
antenna is side mounted (even if the tip is only 6 feet down from the tower top) the tower
itself (or someone else's antenna) can be the lightning rod and take the hit.
Note that all "DB-224"s are not the same... they may all be tower-mounted exposed dipole arrays
with 6 to 8 dB of gain (depending on the pattern), it's the suffix letter that is of utmost
importance:
- the DB-224-A model is 150-160 MHz circular pattern,
- the DB-224-B model is 155-165 MHz circular pattern,
- the DB-224-C model is 164-174 MHz circular pattern,
- the DB-224-E model is 138-150 MHz circular pattern (but try and find one second hand...),
- the DB-224-FAA model is 127-141 MHz circular pattern (it can be shortened to 2m),
- the DB-224-F model is 160-170 MHz circular pattern,
- the DB-224-J model is 276-285 MHz circular pattern,
- and the DB-224-JJ model is 220-225 MHz circular pattern,
- the DB-224E-A model is 150-160 MHz offset pattern,
- the DB-224E-B model is 155-165 MHz offset pattern,
- the DB-224E-C model is 164-174 MHz offset pattern,
- the DB-224E-E model is 138-150 MHz offset pattern (again, try and find one second hand...),
- and the DB-224E-JJ model is 220-225 MHz offset pattern,
- The DB-224 series can be ordered as a single or dual antenna. Just modify the model number by
adding an "S" in the right spot - a DB-224-JJ single antenna becomes a DB-224S-JJ as a dual antenna.
It amounts to separating the elements into two independent antennas on the same mast. Each antenna
has a separate feedline terminated at the bottom of the mast. A DB-224ES-A or DB-224ES-JJ is a dual
feedline antenna with the offset pattern.
- And I've been told that at one point (maybe still can) you could order a new DB-224 less the
tubular mast, and supply your own. Supposedly one group built up a "single antenna" as defined by
their tower agreement that was made up of a UHF stationmaster-type fiberglass stick on the top of
an extended length tube, a VHF DB-224 in the middle, and a end-mount UHF beam clamped a couple of
feet below the bottom element and a few inches above the lower end of the tube.
|
|
A detailed drawing of the DB-224-A and DB-224-E
106 KB PDF file donated by Skipp. Note that the element length
measurements are shown for both the "A" (150-160 MHz) range and the "E"
(138-150 MHz) range. There is enough information here that anyone with some experience bending
aluminum tubing can build one for themselves. Or if you are going to build your own and want
extra strength you could use aluminum rod. |
|
A detailed drawing of the DB-224-JJ
14 KB PDF file Roger White W5RDW measured a DB-224-JJ, the drawing is by Skipp. |
|
Another detailed drawing of the DB-224-E
61 KB PDF file Donated by Doug Zastrow WBØUPJ. Note that the element length
measurements shown in the diagram are for 136-150 MHz frequencies. |
|
More DB-224 wiring harness drawings 56 KB
PDF file Donated by A. Nony Mous. Complete with calculations. |
|
Details of the DB-224-E wiring
harness 1.7 MB PDF file Donated by A. Nony Mous. Additional detailed drawings of
various parts of the wiring harness can be found below (all are PDF files):
|
|
Conversion calculations for moving your DB-224 to
a different band split. 90 KB PDF file All of the magic calculations plus coax
types necessary to redo your DB-224's wiring harness and set the element length and spacing. |
|
Converting a DB-224 or DB-222 to the 2M ham band
Original author KC4WC |
|
The DB-225 is a single element, 5 dB gain dipole station antenna that provides a "semi-circular
radiation pattern" (their term, not mine). It uses a director element that is built into the dipole
assembly to shape the pattern - if you end up with a used one and it is missing the director there's
no telling what the final pattern will look like... The antenna can be ordered for any frequency
from 30 MHz to 174 MHz. The catalog claims that you can stack the antennas and get 8 dB gain
with 2 antennas and 11 dB gain with 4 antennas. The data sheet is very specific that it must
be mounted "2 to 3 feet below the top of the tower or pipe support. At the same time it must be
clear of all guy wires or metal objects for 2 to 3 feet." |
|
From an email from Ken Decker WA6OSB: Here's the paperwork that was shipped with a DB-225. I
thought it might be useful in the R-B Antenna section.
DB-225 data 303 KB PDF file |
|
The DB-228 is essentially two DB-224s on one 41-foot long mast, and can be ordered with a phasing
harness that makes it one antenna - and that makes it the ultimate 2m repeater antenna (10
to 12 dB depending on the pattern). The catalog sheet shows the "normal" mounting has being
a split mount: the top half is above and the bottom half is below the top of a tower (i.e. the
bottom half is side mounted with two clamps at the middle and bottom); however, unless you want to
be the lightning rod the DB-228 can be fully side mounted with the two brackets at top and bottom,
or an optional third bracket can be added in the middle (I certainly would, especially in any area
that has a problem with high winds, antenna icing, or both).
Or if you need extra RX-TX separation: order it with the -S (split kit) option and use it with two
feedlines and a split duplexer as separate DB-224 receiving and transmitting antennas.
Note that on this antenna an A suffix indicates 150-160 MHz, B=155-165 MHz, C=164-174 MHz and
E=138-150 MHz.
DB-228 Data
Sheet 89 KB PDF file DB-228
Instruction Sheet 62 KB PDF file
Here's the instruction sheet that comes in the box with
the DB-228 772 KB PDF Courtesy John Lock KFØM |
|
DB's installation instruction sheet on the DB-264
159 KB PDF file Courtesy of Paul Kelly N1BUG
The DB-264 is a 4 element dipole array that is constructed for any 10 MHz segment of 150-285 MHz.
This is the model that has the feed harness hidden inside the support pipe. I've seen one of these
on 224 MHz, and it's rugged! |
|
Anyone have any data sheets or instruction sheets on the DB-304 ?? |
|
DB's instruction sheet on the DB-314 114 KB PDF
file Courtesy A. Nony Mous
The DB-314 is essentially a 8 UHF dipoles (a DB-408,6.6 dB gain) and 4 high band dipoles
(half of a DB-304, 3.2 dB) on the samemast, with separate feedlines. If you need a commercial
grade dual band antenna, this is it. Or if you are limited to one antenna, then order this guy and
use it as separate 2m and 440 antennas with two feedlines, or with a pair of commercial-grade TX-RX
Corp. (or similar)"diplexers" that put both antennas on one feedline. But don't try and use one on
a 147.09 MHz; repeater paired with a second repeater whose input is 441.275 MHz, or
147.36 MHz; and paired with 442.075 MHz; (I shouldn't have to tell you to do the math...
and it doesn't matter what antenna you have in that situation). |
|
The DB-404 UHF dipole array is two pairs of UHF dipoles mounted to a mast.
Photo Here is the factory data:
DB 404 Data Sheet 95 KB PDF
DB 404 Instruction Sheet 134 KB PDF
Catalog sheet Page 1 879 KB
Catalog sheet Page 2 568 KB
The frequency range suffix: A = 406-420, B = 450-470, C = 470-488, D = 488-512, and the "E" range
is either 482-494 or 440-450 depending on which catalog you read, be very, very careful when
ordering one of these. Do it by frequency range, not suffix letter. The SWR is specified as
under 1.5 (or less) across the entire range specified in the suffix letter. According to the spec
sheet the standard connector is a male N, but I've seen installations with a PL-259 on the harness,
and it looked like a factory harness. |
|
A detailed drawing of the DB-404-B 30 KB PDF file
Donated by Skipp. Note that the element length measurements shown in the diagram are for 450-470 MHz
frequencies. |
|
A detailed drawing of the DB-404-D 28 KB PDF file
Donated by Skipp. Note that the element length measurements shown in the diagram are for 488-512 MHz
frequencies. |
|
The DB-408 is essentially two DB-404s stacked on one longer mast (almost 9.5 feet long) and
can be ordered with one or with two feedlines (the "split kit"). Specify Omni or Offset pattern when
ordering, and if top or side mounting when ordering. For side mounting order the DB-5012 mounting kit.
Here is the DB-408 UHF dipole array factory data: DB-408
Data Sheet 92 KB PDF file DB-408
Instruction Sheet 81 KB PDF file
On this antenna the power limit is 250w, the frequency range A = 406-420, B = 450-470, C = 470-488,
D = 488-512.
The "E" range is either 482-494 or 440-450 depending on which catalog you read, be very, very
careful when ordering one of these. Do it by frequency range, not suffix letter. |
|
A detailed drawing of the DB-408-B 29 KB PDF file Donated
by Skipp. Note that the element length measurements shown in the diagram are for 450-470 MHz
frequencies. |
|
DB-411 UHF dipole array factory data: (PDF files) DB
411 Data Sheet 75 KB PDF file DB
411 Instruction Sheet 223 KB PDF file
|
|
A detailed drawing of the DB-411-B 25 KB PDF
file Donated by Skipp. Note that the element length measurements shown in the diagram are for
450-470 MHz frequencies. |
|
The DB-420 is essentially two DB-408s stacked on one longer mast and can be ordered with
one or with two feedlines (the "split kit"). Specify Omni or Offset pattern, and if top or side
mounting when ordering. |
|
A drawing of the DB-420-B phasing harness
143 KB PDF file
This is the 450-470 MHz version. Anybody have a drawing (or the measurements) for 440-450 MHz ? |
|
The data sheet on the DB-420 UHF dipole array
117 KB PDF file The DB-420 is an array of 8 dual dipoles that can be configured as a single
8-element antenna or as two 4-element antennas on the same mast (conversion requires a different
harness).
|
|
The DB-420 UHF dipole array Assembly
and Mounting Instructions 148 KB PDF file |
|
Factory 1-page data sheet on the DB-492, DB-493 and DB-498
806-960 MHz Yagi beam antennas 133 KB PDF file
This is the data sheet on the welded beams that are 6, 8 or 9 dB. The 492 and 493 are light
duty, the 498 is heavy duty. Phasing harnesses for 2 or 4 antennas are available for up to
15 dB of gain. |
|
Factory 2-page data sheet on the DB-844H90E-XY directed
dipole antenna 122 KB PDF file
806-896 MHz and 870-960 MHz antennas with 12-15 dB of gain. |
|
Factory 4-page data sheet on the DB380
pipe mounts 237 KB PDF file
Also for DB5083 downtilt mounts for panel antennas. |
|
Factory data sheet on the DB-5004 / DB-5030
Outrigger 387 KB PDF file
This is the data sheet on the fiberglass outrigger that supports the Stationmaster and
SuperStationmaster style fiberglass monopoles. You want to use at least one, in really high
wind/bad weather areas I've seen two on a 21 foot SuperStationmaster). |
| | Telewave
Click here for the Telewave on-line catalog |
| |
|
Does anyone have additional data sheets or scans of the box-stuffing literature that
Telewave ships with their antennas? |
| |
|
Telewave
Antenna Connection weatherproofing 89 KB PDF |
| |
|
Telewave
138-152-MHz-Yagi 189 KB PDF
3 elements, 5dB, 500w, 38 inches boom length, 42 inches longest element |
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Telewave 415-450-MHz-Yagi
166 KB PDF
7 elements, 10 dB, 500w, 41 inches boom length, 13 inches longest element |
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Telewave Discone
Antenna 75 MHz to 3 GHz 75 KB PDF
(500w, SWR is between 3:1 and 1.5:1 below 95 MHz, 110 degree vertical beamwidth, 53 inches
tall, 26 inches diameter, shipping weight is 102 pounds) |
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Telewave Discone
Antenna 118 MHz to 3 GHz 90 KB PDF
(500w, SWR is less than 1.5:1, 110 degree vertical beamwidth, 36 inches tall, 25.5 inches
diameter, shipping weight is 10 pounds) |
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Telewave Discone
Antenna 400 MHz to 3 GHz 65 KB PDF
(500w, SWR is less than 1.7:1, 110 degree vertical beamwidth, 48 inches tall, 8 inches
diameter, shipping weight is 41 pounds) |
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Telewave
Dipole Mounting 32 KB PDF |
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Telewave
Dipole Pattern Configuration 30-300-MHz 171 KB PDF |
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Telewave
Dipole Pattern Configuration 300-1000 MHz 179 KB PDF |
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Telewave 45-54 MHz dipole
antenna 127 KB PDF
500 watts, 1 to 2.5 dB, occupies 9 feet of tower space |
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Telewave 138-174 MHz dipole
array 161 KB PDF
(single, dual and four elements, 500w, 1-9 dB depending on element count and pattern) |
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Telewave 138-174 MHz
dipole array 161 KB PDF
(8 elements, 500w, 7-12 dB depending on pattern - and it occupies 41 vertical feet of tower!) |
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Telewave 216-252 MHz dipole
array 161 KB PDF
(single, dual and four elements, 500w, 1-9 dB depending on element count and pattern) |
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Telewave 216-252 MHz
dipole array 161 KB PDF
(8 elements, 500w, 7-12 dB depending on pattern) |
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Telewave 406-512 MHz dipole
array 164 KB PDF
(single, dual and four elements, 500w, 1-9 dB depending on element count and pattern) |
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Telewave 406-512 MHz
dipole array 171 KB PDF
(8 elements, 500w, 7-12 dB depending on pattern) |
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Telewave 800-1,000 MHz dipole
array 162 KB PDF
(single, dual and four elements, 500w, 1-9 dB depending on element count and pattern) |
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Introductory Information for Feedline, Connectors, and Coax
READ THIS FIRST |
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What Does "RG-6" Mean? A
nice explanation of where the "RG" in cable numbers came from. (Offsite link)
Yes, it's TV and Video oriented, but it's still pertinent. And he explains why you want to specify
Belden 1505A for any RG-59 sized video cable, and Belden 1694A for an RG-6 sized cable. |
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A document on the properties of different types
of UHF (PL259) connectors. 4.6 MB PDF file by Allan B. Crites WA9ZZU
As a result of my extensive review of documents in my possession and in response to
the document referenced above I am the author and others only extracted parts to be
used in an Engineering Report which included my measurements and log book gathered
data, and drawings, to which my engineering supervisor appointed by the company
assembled the data and other pages, and added his name first above mine, even
tho I had done the work.
You Kevin Custer, do hereby have my permission to publish this document in its
entirety on your website Repeater Builder. Allan Crites WA9ZZU |
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WA2ISE's chart of the specs of common coax
cables By Robert Casey WA2ISE |
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Another chart of the specs
of common coax cables (offsite link) Courtesy of Coastel Cable Tools of
Syracuse, New York |
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More specifications (bend radius, velocity factor, loss)
of common coaxial cable types By A Nony Mous |
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Yet another chart of cable specifications
of common coaxial cable types By TX-RX Corporation |
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But it's only a couple of dB ! by
Mike Morris WA6ILQ
Connector and feed line losses DO add up! |
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Amphenol Coax Cable Catalog version W1
16 MB PDF Courtesy of John Lovallo W9GC
I have no idea what year this was published, but it has to be pre-1963 as it's pre-ZIP codes. |
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Double Shielded Coax Cable The differences
between RG-142 and RG-400, and why sometimes you DON'T want to use RG-142... by Eric Lemmon WB6FLY
With a few additional notes on RG-214 and RG-223... |
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Shielding Effectiveness.... A 283 kB PDF
Document by Andrew Corp. covering the types and parameters of shielded cables. This is a local copy here
at repeater-builder, the original copy
is offsite at andrew.com. |
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Installing PL-259 connectors on
FSJ1-50A 1/4" Superflex Heliax a photo article by Tony King W4ZT. |
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9913 data sheet 98 KB PDF
from the Belden web site
Belden 9913 has an aluminum foil shield under a tinned copper braid. Like the LMR-nnn cable
(where nnn is any 3 or 4 digit number) it is not appropriate for duplex service. The
original Belden 9913 was an indoor-only low loss version of RG-8/U designed for the old
thick Ethernet. Later versions have a tougher outer jacket, and at one point jumpers made from
9913 were shipped with commercial LMR antennas. |
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MIL-SPEC-C17 for RG-9/U dated
25-July-1946 40 KB PDF courtesy of Eric Lemmon WB6FLY
RG-9 is an older double shielded cable that had a center conductor of 7 strands of 21 ga silver
plated wire, an inner braid of 34 ga silver plated braid and an outer shield of 34 ga unplated
copper braid. |
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MIL-SPEC-C17 for RG-9A/U dated
25-July-1946 40 KB PDF courtesy of Eric Lemmon WB6FLY
RG-9A/U was the same as RG-9/U except that on the A series cable both braids were silver plated. |
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MIL-SPEC-C17 for RG-9B/U dated
07-September-1955 32.3 KB PDF courtesy of Eric Lemmon WB6FLY
This cable has a loss of 5.5 dB per 100 feet at 400 MHz.
Genuine RG-9B/U cable has two silver-plated copper shields and a silver-plated stranded copper center
conductor- just like RG-214/U. In fact, the Cancellation Notice for RG-9 dated 12 November 1969 states,
"Forfuture procurement, use the latest issue of Military Specification Sheet MIL-C-17/75, which covers
Cable, Radio Frequency, Coaxial, RG-214/U." |
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MIL-SPEC-C17
for RG-21A/U and RG-222/U dated 7-sep-1955 82 KB PDF courtesy of Eric Lemmon WB6FLY
RG-21 is considered obsolete and has been replaced by RG-222 in all new designs. This is a high loss
cable, over 30 dB per 100 feet at 400 MHz. |
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MIL-SPEC-C17 for RG-58A/U dated
18-July-1985 268 KB PDF courtesy of Eric Lemmon WB6FLY
This is the mil-spec for real RG-58. Most of what is sold as RG-58 these days isn't anywhere close
to mil-spec stuff - all you have to do is check the density or tightness of the braid, then count the
strands on the inner conductor (and make sure it's tinned).
The mil-spec calls for a tinned copper braid and a center conductor of 19 tinned strands - and I've
found "mil spec" RG-58A/U with a solid center conductor at one HRO store, and I've found "mil spec"
RG-58A/U without the tinned braid or tinned center conductor at both HRO and AES retail stores.
The data sheet says that the good mil-spec stuff has a loss of 4 dB per 100 feet at 50 MHz,
9 dB per 100 feet at 150 MHz, and 17 dB per 100 feet at 400 MHz!
If the good stuff loses 1/4 of your power at 2m or half your power at 440 MHz in just 20 feet
of cable, what's the loss on the cheap stuff going to be?
Note that this is a PVC based cable that can no longer be used in aerospace applications due to the
fact that when PVC is burnt (i.e. with flames) it gives off toxic gas. |
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JAN-C17 for RG-83/U dated
25-JUL-1946 68 KB PDF courtesy of Eric Lemmon WB6FLY
This is the Joint-Army-Navy spec for the 35 ohm coaxial cable whose major use today is in the phasing
harnesses for multi-antenna (or multi-element in a single antenna) arrays. |
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MIL-C-17_92D for
RG-115 Note 2 dated 23-Oct-2000 136 KB PDF courtesy of Eric Lemmon WB6FLY
This cable has a silver plated center conductor, double silver plated shields, is appropriate for
temperatures from -55 degrees C / -67 degrees F to +230
degrees C / 446 degrees F and due to the fiberglass outer jacket is suitable for
direct burial applications. It has a loss (per 100 feet) of 1.6 dB at 50MHz, 2.5 dB
at 100 MHz and 9.8 dB at 1,000 MHz (about 6 dB at 450 MHz from my reading
of the graph on page 6 of the PDF file). The PDF file also has return loss specifications. |
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MIL-DTL-17/60D (with
Ammendment 1) for cable type RG-142 dated 12-Oct-2006 135 KB PDF courtesy of Eric Lemmon
WB6FLY
This is the mil-spec for real M17/60-RG142 - the stiff stuff with a solid inner conductor of silver
plated copper covered steel wire, a solid, extruded PTFE dielectric core, dual 36 ga silver-coated
copper braids, and less than 30pf of capacitance per foot. Note that this coax is intended for use
as RF jumpers in general purpose, high temperature, vibration and movement-free applications,
NOT as feedline. The loss per 100 feet is 3 dB at 50 MHz, and 9.3 dB at 400 MHz. |
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MIL-C-17_119G for RG-174: both courtesy of Eric Lemmon WB6FLY
JAN-C17-119G for RG-174 dated
20-FEB-1991 191 KB PDF
JAN-C17-196B for RG-174 dated
13-AUG-1993 27.2 KB PDF
This is small (less than .15 inch) diameter coax that is the proper size for SMA and SMB connectors.
It works OK up to 1 GHz, but has a 85% braid coverage. The braid coverage is important, but the
major drawback is the very high loss - per 100 feet is 10 dB at 100 MHz, and about 25 dB
loss at 450 MHz. The small size contributes to the low power handling capability - don't run more
than 25 to 30 watts through it at 150 MHz or 20 to 25 watts through it at 450 MHz.
I've seen a melted piece of RG-174... not pretty. And when it shorted it killed the PA deck.
Personally, I won't use it at RF unless I have to, and despite the negatives listed above I do have
a roll of it in my shop: I use it for audio coax in everything I build. My dad (WB6SOX) taught me
a trick that you can use on both RG-58 and RG-174... you can peel back the outer jacket an inch or
more, spread the braid a little just above the end of the jacket and use a spring hook to pull the
center conductor through the hole in the braid. You can then put some tubing (heat shrink or normal)
over the braid pigtail. This trick gives you two conductors that you can solder to dual pin
termination, be they solder lugs, pins on a connector, etc. |
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MIL-SPEC-C17/74C for
"Cables, Radio Frequency, Flexible, Coaxial, 50 Ohms, Unarmored M17/74-RG-213 and Armored M17/74-RG-215
dated 18-July-1985 311 KB PDF courtesy of Eric Lemmon WB6FLY
This is the mil-spec for real RG-213 - the stuff with 17 strands of copper wire, a solid, polyethelene
dielectric core, a copper braided shield with better than 95% coverage. Note that this cable is intended
for use as feedline in general purpose low temperature applications. It has a loss of 1.2 dB
per 100 feet at 50 MHz, and 4.8 dB per 100 feet at 400 MHz (over 50% of your
power!).
Note that this is a PVC based cable that can no longer be used in aerospace applications due to the
fact that when PVC is burnt (i.e. with flames) it gives off toxic gas. |
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MIL-SPEC for RG-214 dated
24-Sep-1986 335 KB PDF courtesy of Eric Lemmon WB6FLY
RG-214 is the good double-shielded coax that has the stranded silver plated center conductor (each strand
is individually silver plated). Both shields are made from 34ga silver plated copper wire. The inner
shield exceeds 95% coverage and the outer shield equals or exceeds 98% coverage. It has a loss of
1.7 dB per 100 feet at 50 MHz, and 6.8 dB per 100 feet at 400 MHz (over
3/4 of your power!).
Note that this is a PVC based cable that can no longer be used in aerospace applications due to the
fact that when PVC is burnt (i.e. with flames) it gives off toxic gas. |
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MIL-SPEC for RG-214 dated
1991 215 KB PDF courtesy of Eric Lemmon WB6FLY
This is the new RG-214 that meets the requirement of the vertical flame test. It has the aluminum coated
polyester tape layer between the outer braid and the outer jacket. |
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This
is Amendment 1 to MIL-SPEC C-17/75F for RG-214 and RG-365 dated 1998 4.4 KB PDF courtesy
of Eric Lemmon WB6FLY
This is simply an administrative update. |
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RG-222/U - see RG-21 above |
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MIL-SPEC C-17/84B for RG-223 dated
1977 388 KB PDF courtesy of Eric Lemmon WB6FLY
RG-223 has been pretty much replaced in all amateur and LMR applications by RG-400. RG-223 is an
RG58-sized coaxial cable that has a silver plated solid center conductor and double shielded silver
plated braid. It has a loss of 4.8 dB per 100 feet at 50 MHz, and 12 dB per
100 feet at 400 MHz (in other words, less than 10% of your power makes it to the other
end...)
If you read the spec sheet carefully you will see that RG-223 is rated for just 86 watts at 400 MHz.
For higher power in this size cable you will want to use RG-400. RG-223 also has 50% greater attenuation
at 50 MHz and 15% greater attenuation at 400 MHz than RG-400.
Note that this is a PVC based cable that can no longer be used in aerospace applications due to the
fact that when PVC is burnt (i.e. with flames) it gives off toxic gas. |
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MIL-SPEC C17/127C-RG-393 for cable
type RG-393 dated 11-May-1981 293 KB PDF courtesy of Eric Lemmon WB6FLY
RG-393 is the modern replacement for RG-214. It has similar construction with the stranded silver plated
center conductor (each strand is individually silver plated). It has a solid extruded PFTE dielectric core.
Both shields are made from 34ga silver plated copper wire. The inner shield exceeds 95% coverage and the
outer shield equals or exceeds 98% coverage. It has a loss of 1.7 dB per 100 feet at
50 MHz, and 5 dB per 100 feet at 400 MHz. Page 4 of this PDF has a return loss
spec and graph. |
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MIL-DTL-17/128B (with
amendment 2) for cable type RG-400 dated 25-Feb-2005 94 KB PDF courtesy of Eric Lemmon WB6FLY
RG-400 is the RG58 size coax that has construction similar to RG-214. It has the stranded silver plated
center conductor (each strand is individually silver plated). It has a solid extruded PFTE dielectric
core. Both shields are made from 34ga silver plated copper wire. Both the inner and outer shields exceed
93% coverage. It has a loss of 3.2 dB per 100 feet at 50 MHz, 6 dB per 100 feet at
150 MHz and 10.55 dB per 100 feet at 400 MHz. Page 4 of this PDF has a return loss
spec and graph.
Note that if you put 100 watts at UHF into a three-foot long jumper you will get about 93-94 watts out
the other end, with a 6 to 7 watt loss in just THREE feet. It is high grade jumper material, not feedline! |
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Andrew FSJ1-50A spec sheet 124 KB PDF
This is the 1/4" superflex product with the copper plated aluminum center conductor... It has
2.2 dB loss per 100 feet at 150 MHz and 4 dB loss per 100 feet at 450 MHz. |
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Andrew LDF1-50 spec sheet 126 KB PDF
This is the 1/4" regular product with the corrugated copper jacket and the copper plated aluminum center
conductor... It has 1.52 dB loss per 100 feet at 150 MHz and 2.71 dB loss per
100 feet at 450 MHz. |
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Andrew LDF2-50 spec sheet 121 KB PDF
This is the 3/8" regular product with the corrugated copper jacket and the copper plated aluminum center
conductor... It has 1.28 dB loss per 100 feet at 150 MHz and 2.29 dB loss per
100 feet at 450 MHz. |
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Andrew LDF4-50A spec sheet 199 KB PDF
This is the 1/2" regular product with the corrugated copper jacket and the copper plated aluminum center
conductor... It has 0.815 dB loss per 100 feet at 150 MHz and 1.447 dB loss per
100 feet at 450 MHz. |
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Andrew LDF5-50A spec sheet 167 KB PDF
This is the 7/8" regular product with the corrugated copper jacket and the copper plated aluminum center
conductor... It has 0.45 dB loss per 100 feet at 150 MHz and 0.81 dB loss per
100 feet at 450 MHz. |
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Andrew LDF6-50 spec sheet 118 KB PDF
This is the 1 and 1/4" regular product with the corrugated copper jacket and the copper plated aluminum
center conductor... It has 0.3 dB loss per 100 feet at 150 MHz and 0.544 dB loss per
100 feet at 450 MHz. |
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Andrew LDF7-50A spec sheet 128 KB PDF
This is the 1 and 5/8" regular product with the corrugated copper jacket and the copper plated aluminum
center conductor... It has 0.25 dB loss per 100 feet at 150 MHz and 0.467 dB loss per
100 feet at 450 MHz. |
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We'd like to have similar info on the Heliax connectors. |
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Converting between dbm and millivolts or microvolts A
no-math graphical calculator. It's only a xerox copy of the metal rim of a attenuator wheel from a
Measurements Corp. Model 80 RF Signal Generator... but it's very handy. Courtesy of Ray Von Neumann
K6PUW
I suggest that you print this out and tape it to the front panel of your signal generator
that is calibrated in µV and mV only. Once you realize how dbM numbers work
you will find yourself referring to it on a regular basis. |
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Converting between dbm and millivolts or microvolts
A no-math tabular calculator (a lookup table). The above xerox of the attenuator scale is easier
to use. |
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dBm to Microvolts Conversion Chart 8 kB PDF By
IFR Corp. The above xerox of the attenuator scale is easier to use. |
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An online intermod calculator
from Audio Technica Note that this is oriented to wireless microphones, but since it handles
up to 30 frequencies it is very handy. (offsite link). |
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Another downloadable intermod calculator This one is
shareware written by KE6QH. |
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This downloadable calculator program figures
intercept points and device intermod levels This one is is from Kessler Systems Inc.
(offsite link) |
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This online calculator program from TCS
Consultants, Inc. saves the site description to a 'cookie' file on your computer. (offsite
link) |
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Online fade margin calculator
program from TCS Consultants, Inc. This is neat! (offsite link) |
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FCC HAAT (Height Above Average
Terrain) Calculator (offsite link to the FCC web site) |
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FCC Coordinate Calculation Program
(offsite link to the FCC web site)
This is a useful calcualtor for point-to-point links... "This program will calculate the end
coordinates, in degrees, minutes and seconds, given an initial set of coordinates, a bearing or
azimuth (referenced to True North or 0 degrees), and a distance..." |
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FCC Coordinate Conversion
Program (offsite link to the FCC web site)
This utility permits the user to convert latitude and longitude between decimal degrees and degrees,
minutes, and seconds. For convenience, a link is included to
the National Geodetic Survey's NADCON
program, which allows conversions between the NAD83 / WGS84 coordinate system
and the older NAD27 coordinate system. NAD27 coordinates are presently used for broadcast
authorizations and applications." |
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FCC Distance Calculation Program
(offsite link to the FCC web site)
This program will calculate the distance and azimuth (referenced to True North) between two sets of
coordinates on the earth."
The last four calculators above are courtesy of Dale Bickel of the USA Federal Communications
Commission. The FCC also has a number
of "Conversions" calculators including FM Channel to Frequency, FM Frequency to Channel, TV
Channel to Frequency Band, Feet to/from Meters, Miles to/from Kilometers, dBu to/from mV/m, kW
to/from dBk, Relative Field, Transmission Line Efficiency, and more.
|
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An old DB Products DOS program that calculates down-tilt for
antennas 128 KB ZIP file |
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An old DB Products DOS program that plots some antenna patterns
383 KB ZIP file |
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An old DB Products DOS program that gives you some insight into
the effects of side-mounting vertical antennas 134 KB ZIP file
The above three programs were supplied by Dave Gartner WD6AXM.
|
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Introductory Information on mobile antennas
READ THIS FIRST |
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A Motorized Mag Mount for Mobile
Antennas 1.53 MB PDF from the May 2005 issue of QST
An interesting modification to an off-the-shelf Diamond mount. |
|
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Base and mobile antenna cutting chart from Larsen
Antennas 684 kB PDF from the Larsen web
site, specifically the Technical
Reference page. (offsite link) |
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Mobile antenna patterns and
designations 1.6 MB PDF from the Larsen web
site. |
|
|
Low band radios that cover a wide frequency range (like the GE Delta, GE Rangr, Motorola
Syntor X or Syntor X-9000 which covers 28-54 MHz in one range) have a big problem: the antenna
bandwidth is much narrower than the radio is - most low band antennas are limited to roughly
750 KHz to 1 MHz in bandwidth.
The mobile HF antenna tuners made by YaeComWood (Yaesu, Icom and Kenwood) all require
serial data from the HF mobile for the frequency information. In addition, very few of them will
work on 6 meter frequencies. Motorized autotuning antennas have been around since before
World War II, but a really good design is fairly recent (the so-called "screwdriver" design,
invented and patented by Don Johnson W6AAQ in 1991 - almost all other units on the market are
a direct pirated copy or a enhanced redesign of the original). Back in mid-1985 Motorola came up
with a no-moving-parts solution: a "Diplex Antenna Matching" kit that allowed two differently cut
low band whip antennas on one radio (i.e. one antenna could be on 36 MHz and the other on
43 MHz), and set up in a way that prevented them from interfering with each other. The two
antennas can be cut to any two low band frequencies. Here
is the complete documentation on the kit (Motorola manual part number 6880100W86, a 1.9 MB PDF),
which contains three pages of info - enough to duplicate it yourself.
There is a local rumor that someone has extended the Motorola writeup and come up with a way
to use three different whip antennas to allow three 1-mhz-wide "windows" but I've not seen it.
At the moment if you need more than two fixed 1-mhz-wide "windows" then you need a good screwdriver
antenna and a self-contained autotuner like one made by SGC. The phrase "self-contained" is
important here, as the autotuners from YaeComWood are dependent on the radio they are connected
to for serial frequency data and cannot be made to work with common low band Motorola or GE land
mobile radios.
I have heard that there is an antenna tuner made for the "screwdriver" antennas that
will work in this situation (from 28-54 MHz) but do not know who the manufacturer
is. Let me now who it is and I'll put a link here.
Yes, there is a need. Picture a mobile EOC comm van that has a wideband Syntor X9000.
Air Force SAR uses 33 Mhz frequencies. The California Highway Patrol uses 39-43 MHz.
Red Cross has several channels around 47.3 to 47.6 MHz. The National Guard has channels in
the 49 MHz range. Plus any 10m or 6m channels.
PS - if anyone wants to complete the Motorola writeup with the the coax measurents for 10m and
6m, or supply a replacement cutting chart that goes down to 28 MHz (or even 27 MHz)
and up to 54 MHz we will publish it. |
|
|
The KØBG web site (link to another web site)
Alan Applegate KØBG lives in Roswell, New Mexico and has created a very good reference
web site for mobile amateur radio operators. I was pointed to it by a police department radio
tech. While the site has a lot of material oriented to HF mobile, there is a lot of information
that is relevant to VHF operation as well. Just look at the index along the left edge. If you
look at nothing else, the Alternators and Batteries page and the Antenna Mounts page is worth
your time. And if you have (or are going to buy) a screwdriver antenna then his comments are
REALLY worth your time. |
|
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W8JI's page on Inductors and
Loading Coil Current (Mobile and Loaded Antennas) (link to another web site)
Charles Rouch has a good web page on loading coils and how they work. It's HF oriented but the
math is the same. |
|
|
Urgent Communications
Mobile Radio Installation Notes (link to another web site)
Urgent Communications is a two-way radio industry publication, and their web site has some
notes on mobile radio installations. |
|
|
You've heard of co-phased antennas? Well, here's the
co-tanger antenna. |
|
|
A mobile coaxial sleeve
dipole antenna for 2m 450 kB PDF from the Aug 2001 issue of QST
The sleeve vertial (actually a coaxial dipole) is handy when you have no ground plane to work
with, like on a bicycle, a motorcycle saddle bag or a Corvette rear deck. Back in the 1970s
Art Gentry K6MYK used to have both VHF and UHF homebrew ones on his car, and said that
they outperformed any 1/4 or 5/8 wave antenna. |
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440 MHz Folded Dipole Repeater Antenna
222 kB PDF file This is a two page PDF file of the classic 73 Magazine construction
article by Chuck Kelsey WB2EDV - yes, you can build yourself a DB-224 folded dipole array. |
|
A Portable Quad for 2 Meters
1.19 MB PDF by R. J. Decesari WA9GDZ from the September 1980 QST.
While this was designed as a backpacking antenna it makes a decent t-hunting / fox
hunting antenna that you can store in a hard case made from a piece of plastic sewer pipe with a
glued plug on one end and a threaded cap on the other end. |
|
Homebrew Coaxial Dipole for VHF
or UHF 1 MB PDF from the July 2009 QST by John E. Portune, W6NBC
Another variation on the coaxial dipole originally intended for base station use for 146, 220
or 440 MHz. Performance is equal to a J-pole, but it is smaller, less obtrusive and easily
weatherproofed. Personally, I think John's design could be easily adapted to be used as a mobile
no-ground-plane-required antenna. |
|
Garbage In, No Garbage
Out 2.5 MB PDF By John E. Portune, W6NBC from the July 1996 issue of 73 Magazine.
Another John Portune article - this one on a homemade VHF cavity. |
|
The Quadrifilar Helix as a 2 Meter
Base Station Antenna 3.16 MB PDF By John E. Portune, W6NBC from the October 2009 QST
Yet another John Portune article - this one on a homemade VHF antenna that is equally good on satelites
as on mobiles. |
|
Cheap Yagi Antennas for
VHF / UHF 404 kB PDF By Kent Britain, WA5VJB for the Clear Lake Amateur Radio Club
of Houston, Texas.
This article describes a easy-to-build inexpensive yagi (beam) antenna that can be customized to cover
any VHF to UHF frequency. Measurements are given for 144, 222, 420, 432, 450, 902 and 1296 Mhz. |
|
Ground Plane Antennas
for 2m, 220 and 440 Mhz 93 kB PDF courtesy of the ARRL |
|
6 meter low-pass
filter 285 kB PDF courtesy of the ARRL |
|
A QST article on a homebrew
discone 374 kB PDF file from the May 2003 issue
The article describes it as 144 through 450 MHz but it would work just fine at Civil Air Patrol
(CAP) frequencies (just plug 139 MHz into the sizing formula) and at GMRS frequencies. Personally,
I'd use copper screening, not steel hardware cloth. And discones aren't limited to 2m and up, as
this photo of a commercial 25-75 MHz discone will
show (photo by WA6ILQ). While it looks like the support mast is on a rooftop air conditioner, it is
actually mounted into a tripod base about 20 feet on the far side of the unit. A search of the QST
archives shows a 302 kB PDF article on constructing a 40 through 10 meter
discone in the July 1975 issue and a follow-up/correction in September. |
|
A Copper Cactus Dual-Band
J-Pole Antenna Project By Tony Petersen N7QVC |
|
Build a Rugged Half-Wave Coaxial
Antenna This is a coaxial sleeve dipole antenna and is the same basic design as the
California Highway Patrol uses at some base stations (others use full dipoles, ot even a pair of
them). Courtesy of the Scanner Buff Network (offsite link) |
|
A homebrew Digital TV Antenna
Project 644 kB PDF By Make Magazine
If you are going to make one I suggest you first seal the wood with two or three coats of sealer. |
|
Seven dB for Seven Dollars
844 kB PDF by Nathan Loucks WBØCMT
A homebrew three element two meter beam made from PVC pipe. You might want to use outdoor-rated pipe. |
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Homebrew vertical antennas for 2m and 6m
from PVC pipe Courtesy J. C. Bishop, VK2ZOI (offsite link) |
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If anyone has any other good homebrew antenna projects let WA6ILQ know. |
This web page created and first posted 14-Oct-2004.
Layout and hand coded HTML © Copyright 1995 and date of last update by Mike Morris WA6ILQ
