There are other good articles on the Construction Projects page.

This web page was created in July 2004 by consolidating two technical index pages and the downloads page. On 14-Oct-2004 the information about intermod calculators,cavities, duplexers, feedlines, isolators, circulators, preamps, and other antenna system items was split off to the Antenna Systems page.   In March 2005 the antenna information was moved to its own directory.

	USA Spectrum Allocation Chart   The official chart straight from the US National Telecommunications & Information Administration (NTIA) Office of Spectrum Management (OSM)   (95kb PDF file) Alternate source - from the NTIA server: http//www.ntia.doc.gov/osmhome/allochrt.pdf (off-site link)
	Repeater Application notes and Articles   offsite link to Chip Angle's web site Look for the "Repeater applications notes" - proven repeater system design techniques from a VHF / UHF / weak signal / contesting fan and RF design guru
	How to look up an FCC ID number   Sometimes being able to determine who made that device is sometimes very useful... (offsite link - to the FCC server)
	How to look up a tower location   Lists all FCC registered towers - broadcast, cellular, everything... (offsite link - to the Berkana server)
	Tower lookup page at the FCC web site   (offsite link - to the FCC server)
	ChipDir   The Master Chip Lookup Web Site (offsite link to a Dutch server)
	How do I measure sensitivity on this FM receiver?   Measuring receiver sensitivity by Jeff DePolo  WN3A.
	Measuring Sensitivity - SINAD vs Quieting   There are two ways to measure sensitivity, and this article compares them, complete with clickable audio files... by Robert W. Meister WA1MIK
	Measuring Receiver Effective Sensitivity   Repeater receiver sensitivity on the workbench is irrelevant - it's how well it works at the repeater site in its intended use... by Chris Boone, WB5ITT
	Speaking of Preamps...   A discussion thread about 900 MHz preamps extracted from the AR902MHz Yahoo! Group. The information presented herein is applicable to other bands as well.
	Fundamentals of RF and Microwave Noise Figure Measurements - Application Note 57-1   712KB PDF by Agilent Technologies (the old HP Instrument Division)
	10 Hints for Making Successful Noise Figure Measurements - Application Note 57-3   967KB PDF by Agilent Technologies (the old HP Instrument Division)
	Practical Noise-Figure Measurement and Analysis for Low-Noise Amplifier Designs - Application Note 1354   1.7MB PDF by Agilent Technologies (the old HP Instrument Division)
	Resolving high-band paging transmitter interference   by Bryan Dorbert N3ST
	An explanation of Audio Processing   A reply by Jeff DePolo WN3A.
	900 MHz Frequencies to Avoid When You Set Up Your New Repeater   There's a lot of grunge on 900MHz and amateur radio is secondary there, and we just have to avoid it. Here's a list of channels to avoid, plus some important information that restricts amateur use in some areas of the United States...
	While it's not worth a separate article, you don't want to have a UHF repeater input between 446.0 and 446.100. The European FRS radios (the service is called "PMR 446") uses 8 narrowband channels in that range (complete with user-selectable CTCSS codes), specifically: (1) 446.00625, (2) 446.01875, (3) 446.03125, (4) 446.04375, (5) 446.05625, (6) 446.06875, (7) 446.08125, (8) 446.09375 ... sounds like a good area for P25 repeater outputs or point-to-point packet links.
	How to install RF modules and transistors   A step-by-step procedure from the experts   by RF Parts company Original source - from the RF Parts server: http://www.rfparts.com/install.html (off-site link)
	The FCC Class of Station Code list   Ever wonder what an FB2J, or a FB4, or a FB6L is?   This is a local copy of the one at the Percon Corporation web site.
	How about 1200mHz?  Any thoughts on this?   A reply by Jeff DePolo WN3A.
	1200 MHz / 23 cm repeaters in the U.K.  An article by Andy G8VLL.
	Terminology used around repeaters     An on going glossary updated regularly. Contributions welcome.
	Why should you really spend $50 to re-crystal a channel element or ICOM?   by Kevin Custer W3KKC, Eric Lemmon WB6FLY, Jeff DePolo WN3A, Robert Meister WA1MIK and Mike Morris WA6ILQ
	Flat Audio, and Pre & De Emphasis explained.  By Morris, DePolo, Schmid, and Custer.
	Pre & De Emphasis, Explanation and Assistance: Running the Numbers.   By Matt Lechliter W6KGB
	More on why Pre-emphasis & De-emphasis, with examples on the Motorola Micor   By Paul Sexauer K3VIX.
	FM Standards Article from Ham Radio magazine 1970   This article is a technical analysis of the wideband (+/-15KHz) and narrowband (+/- 5KHz) modulation standards. With the conversion from narrowband to even lesser deviation standards it's worth reading. By Les Cobb W6TEE
	Two Meter FM repeater separation - 20 kHz Yes, 15 kHz No... from Ham Radio magazine 1985   5 kHz deviation with a 3 kHz audio cutoff creates a signal at least 13 kHz wide, counting only the first set of sidebands. That's why many states went from 15 kHz to a 20 kHz channel bandplan on 2m.   This article gives the theoretical information and proves the point (through VHF FM receiver selectivity measurements) that you have more usable repeater pairs using 20KHz spacing than with 15KHz spacing.   By By Chris Kelly WD5IBS and Virgil Leenerts WØINK
	The Remote Base - An Alternative to Repeaters... from Ham Radio magazine 1977   Recommended reading for those wishing to relieve congestion on the vhf bands - a definitive description of the difference between remote-base stations and repeater stations   By By Gordon Schlesinger WA6LBV, and William F. Kelsey WA6FVC
	How much PL Deviation should I run?   by Kevin K. Custer  W3KKC
	Eliminating the long squelch noise bursts when using CTCSS (PL / CG)   The use of "And Gating" the logic signals, by Kevin K. Custer  W3KKC
	Motorola PL and DPL codes   The standard list of codes extraced from a Motorola RSS Help file, compiled by Robert W. Meister WA1MIK
	How do I link two or more systems together?   by Kevin K. Custer  W3KKC
	How can I remote a phone line to my repeater site?   by Kevin K. Custer  W3KKC
	Programming your repeater controller without a radio or a phone line.   by Mike Morris WA6ILQ
	Repeater Courtesy Beeps   by Mike Morris WA6ILQ   Sample tone info plus telephone call progress tone specs
	How do voting comparators work?   by Mike Morris WA6ILQ
	How does a Voter and Remote Receiver work ?   by Duane Hall and Kevin Custer W3KKC
	Passive Repeaters   by Kevin K. Custer  W3KKC
	Some Thoughts on Solar Power and Other Off-The-Grid Repeaters   by Mike Morris WA6ILQ   Some ideas on what to do when there's no power line...
	Weather radios, SAME decoders, and amateur repeaters   by Mike Morris WA6ILQ   Yes, you can have a weather alert or warning receiver activate your repeater - as long as you stay withing the rules...
	A Phone Line Busy Sensing Circuit   By Monte Smith, WDØDIR, from ACC Notes, April, 1986
	A very interesting Pacific Bell press release from 1990 that a number of California repeater and remote base operators have used to force Pacific Bell to grant residential phone rates to mountaintop radio sites.   The arguments made are simple and compelling and might work anywhere.   Well worth reading! (the monthly rate certainly has changed!)
	AC Power Information - Safety Issues when dealing with commercial AC power.   by Mike Morris WA6ILQ
	But it's only a couple of dB !    by Mike Morris WA6ILQ     Feed line losses DO add up!
	dB to voltage conversion table (both 50 ohm and 75 ohm)   by Mike Morris WA6ILQ
	Return loss to VSWR table   by Mike Morris WA6ILQ
	Building Your Own CATV Hardline Matching Transformers   By Kevin Custer W3KKC
	CANUSA Heat Shrinkable Tubing   Great for sealing antenna and coax joints
	Poor Man's Spectrum Analyzer   Spectrum Analyzer Kit by Science Workshop (offsite link)
	Modulation Spectrums   How audio frequency, filtering, and deviation affect your transmitted FM signal, how to prevent excessive deviation and splatter, shown with dozens of spectrum analyzer traces. By Robert W. Meister WA1MIK
	Why every ham owes Art Gentry W6MEP a dept of thanks   The story of how one man started a repeater revolution. By Bill Pasternak WA6ITF (From QST March 2004)
	A very good primer on basic, single-supply, op-amp circuits   A Texas Instruments Application Note. 160kB PDF file.
	Op-Amp Design Reference   Another Texas Instruments Application Note. A lot more technical detail info than the primer above. 2MB PDF file.

There are some more good articles at http://www.ad5x.com/articles.htm and at http://www.ad5x.com/presentations.htm.

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This web page created 20-Aug-2004

This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors.   All Rights Reserved, including that of paper and web publication elsewhere.