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The 'Mastr' Index of GE Conversion Information
Maintained by Kevin Custer WJ8G 		   
General Electric / Ericsson / Com-Net Critical Communications / M/A-Com / Tyco / Harris (whatever their name is this month) Radios

Over the last several years the company originally known as the Land Mobile Radio Division of General Electric Company has been sold several times. The names have included General Electric, Ericsson, Com-Net Critical Communications, M/A-Com, Tyco and now Harris. Just to keep things simple on this page we are going to use the name GE exclusively, no slighting or denigration of the current owner is intended.

There are three mailing lists that cover GE radios. The first, YahooGroups GE, covers anything GE, the second, YahooGroups GE-MastrII covers just the Mastr-II series, and the third is for the Mastr-III series.

If you are at all serious about any of the GE radios I suggest that you join one or more of the mailing lists.

For quick access to model-specific information use these in-page jumps:
Century II       Custom MVP       Delta       Exec II Info       Frequency Agility       LBIs
Manuals & Technical Info       Mastr II Mobile and Station       Mastr II Mobile
Mastr II Station       Mastr III Station       Mastr Pro       MLS       Mobile Suppliers
Monogram       MPD       MPA       M-RK       MVS       PCS       Phoenix & Phoenix SX
Rangr       220 MHz Conversions       Test Sets and Tuning Tools       Trivia & Misc.

We have very little information on the Mastr IIe or III series.
Would someone like to write an article or two on them?

Technical Information:

Currently stocked manuals can be ordered from the Customer Care Center at 800-368-3277 or call the Publications department directly at 434-832-6592.
The "Mastr" list of LBIs      Over 2 gigabytes of free downloadable PDF'd GE Tech Manuals
Finding a Manual for a GE Mobile Radio      By Eric Lemmon WB6FLY
List of Ericsson Technical Publications      3 MB PDF file. Now we just need to find the two CDs!
GE Technical Information      By Duane Hall of Hall Electronics
The GE email list server      For people seeking information on General Electric or Ericsson equipment
The GE Mastr II email list server      For people seeking information on GE Mastr II's
GE Manuals from Ted Jansen      A good source for original GE manuals
GE Duplex Operation Curves      Donated by Dave Kaar KA9FUR      Curves that show how much total receiver to transmitter isolation is needed for different GE Station configurations.
GE Part Number to Generic Part Number List      Donated by Jim Cannon K7KL      A list that allows cross reference from original GE part numbers to generic part numbers
GE Product Code Publication Indexes      Compiled by Robert Meister WA1MIK      An alphabetical list of the various product code publication indexes. References to several of these are in the text descriptions above.
Some Older M/A-COM Data Sheets      Compiled by Robert Meister WA1MIK      A bunch of older (1982) M/A-COM data sheets for combiners, couplers, filters, etc.

Information applicable to both the Mastr II Mobile and Station:

Combination number decoder page for the Mastr II      An offsite page that will decyper your combination number into general information about your radio. By Dave Cochran - NØTRQ
The GE Mastr II email list server      For people seeking information on GE Mastr II's
GE Crystal Information       A 12 page PDF file about 500 KB, by Doug Bade KB8GVQ
This is a PDF of all GE crystal formulas in the Service Parts Book.
Basic GE Mastr II ICOM information      Basic differences between EC, 5C and 2C (with pictures).
GE Mastr II ICOM information      Everything you wanted to know about the GE ICOM's     (Hall Electronics offsite link)
Why should you spend $50 to re-crystal a channel element or ICOM?   by Kevin Custer WJ8G
A schematic of the exciter audio "blob"     Donated by A. Nony Mous
A cleaner schematic of the exciter audio "blob" above     Redrawn by Robert Meister WA1MIK
A Mastr II S-Meter Circuit     By Andy Kadvan KA8R from an old issue of ACC notes (see the ACC page at this web site)
A crystal frequency calculator for the Mastr II     A downloadable Excel spreadsheet from John M. Kester KD6FVA
Squelch modification for the Mastr II      A modification for making the Mastr II squelch work better by Kevin Custer and Scott Zimmerman
Installing a TS-64 into a Mastr II station      A photo article based on original information from Doug Sharp K2AD.
GE Mastr II Bandsplit Modification      Converting a 450-470 radio to 420-440 Mhz by Matt Lechliter W6KGB.
While the text was written for a station the instructions will work for a mobile as well.
Help!! My UHF Mastr II self quiets after conversion     By M. Scott Zimmerman N3XCC
Help, my Mastr II® has lost receiver sensitivity!      Some Mastr II front end helical castings grow internal whiskers and short themselves out
Mastr II intermittent sensitivity      By Joe Szczech, Jr. K1IKE
An issue with Mastr II front end helical coils that break loose from the casting.
Mastr II I-F alignment procedure      By Patrick M. Conway WA6JGM
IF alignment for Mastr II, Exec II, and Custom MVP radios.
Identifying UHF PA deck components      Donated by A. Nony Mous
A table of part numbers that will help identify what range a PA deck was made for.
A GE Technical Services Memo on substituting the UHF PA transistors      Donated by Darrell Manning KI4BST
The RF power transistors used in the 4-transistor PA deck, part number 19A134171P2 (similar to SGS-Thompson SD1366-07) are no longer available. This writeup explains how to use Motorola MRF646s instead. It requires swapping 16 capacitors (or paralleling across them).
Multiple comment threads over the years on both the GE Mastr II and the repeater-builder yahoogroups have pointed out that the earlier UHF GE Mastr II PA deck had a failure problem. The Z-Matcher was the solution to this (see the articles below). Installing an isolator at the PA output cured the problem(s) in all cases. The best solution is to install a Z-Matcher AND an isolator. Make sure that the isolator load is large enough, and always follow an isolator with a pass cavity. An article about the GE Z-Matcher can be found here. Additional information can be found in the Antennas section of the repeater-builder web site.
From the repeater-builder yahoogroup: Any time I see someone complaining they are unable to get rated sensitivity from a 150.8 to 174 MHz Mastr II receiver, I find the fix is usually correcting a low Local Oscillator injection level. The easiest way to insure you get good sensitivity when using a commercial split receiver on 2M is have the crystal company calculate and build a crystal for high-side injection. This allows the local oscillator and multiplier chain to work inside its intended range without changing any components. Otherwise, if you have a low-side injection crystal you'll have to do some mods to get the injection level up.
It's a lot easier to just use high side injection. And note in the previous paragraph that the writer said "crystal"... The crystal is inside the ICOM, and you will want to read the ICOM recrystalling article above.

Mastr II Station Conversion Information:

If your station conversion involves changing from from carrier to tone squelch (or digital tone squelch), or from tone squelch (or digital tone squelch) to carrier squelch then you need to change several jumpers inside the radio AND on the 10vDC regulator card. Don't forget the regulator card jumpers! If you do, you will be chasing your tail for days!
Product Code file #S3 - cracking the combination number on the later generation Mastr II Station cabinet      158 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "S3" followed by a "D", "S", "P" or "V" followed by an "O" or a "C". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your station, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
Product Code file #67 - cracking the combination number on the earlier generation Mastr II Station cabinet      302 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "D", "S", "P" or "V" followed by an "O" or a "C". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your station, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
If your station was shipped with multiple receivers you will need Product Code file #75.
If your station started out life as an IMTS station you will need Product Code file #22.
The NHRC-M2/SC Repeater Controller Interface Board for General Electric Mastr II Stations from NHRC   (offsite link)
A really handy board that plugs into the GE station card cage and allows a VERY clean interface method.
GE Mastr II Station Conversion Info      from Joseph Hogan W4XE      (offsite link)
Some writeups that Joseph Hogan W4XE put together for the Northern Alabama Repeater Association. Topics include Mastr II station Basics (includes a photo tour, is well worth reading!), the IDA Panel, battery backup, Polyphasers, CAS and RUS buffering, and the repeater transmitter CG tone encoder.
Mastr II Station to Repeater Conversion      By Don Woodward  KD4APP
GE Mastr II Station Power Supply Safety Note      By John Holden N7IQV
If you are running a "real" GE factory supply you need to read this writeup on how to fix a design / manufacturing error.
How to add a PTT disable switch to a Mastr II 10vDC Regulator / Station Control Module      By M. Scott Zimmerman N3XCC
Another take on the above that uses a single switch for both forced transmit and transmit disable   (with photos)      By Chuck Kelsey WB2EDV
No matter whose conversion article or controller interfacing article you use you need to do one of the two above mods to your 10vDC regulator card. It just makes debugging and maintenance a lot easier.
Pion & Simon Electronics      Mastr II Station Controllers that plug right in to the GE card cage! And they really work great!
Don't forget the regulator card jumpers! The Pion & Simon documentation mentions them but some folks still overlook them.
Interfacing the Mastr II Station to an ACC 850 Repeater Controller      3.15 MB PDF file.   Scanned from an old issue of the ACC Notes, developed by the folks at ACC
Interfacing a GE Mastr II Base Station/Repeater to an Scom 7K controller      An off-site link to a PDF at the Scom web site - Scroll down to the section titled "Getting the most from your S-COM products" section and look for "Interfacing a GE Mastr II Base Station/Repeater to a 7K".   The actual file that you will end up downloading is titled 7KGEM2BS.PDF and is about 19 KB.   Well worth reading, even if you end up with some other companies controller.
Comments on the GE Mastr II Power Amplifier, and why they die      By Fred Seamans W5VAY
An experience repairing a GE Mastr II 100w UHF Power Amplifier      By Robert Meister WA1MIK
Repairing the GE Mastr II Station Power Amplifier      By Ray Vaughan KD4BBM
Using the 40-50 MHz 50-100w PA as a Linear Amplifier      By Chuck Schreiber K9VPE
A photo of the intermittent and continuous Mastr II RF Power Amplifier heat sinks
This is the manual for the 19D432500G1 / G2 / G3 standard 10-bit dip-switch style Mastr-II Channel Guard board - LBI-31056 Version G
Additionally, as a shortcut, here is the tone table (see the lower right corner)     123 kB (note that "X"-marked bits are the open switches!)
Notes:
1) The G1 board is the encode-decode board,the G2 is encode-only, G3 is decode-only.
2) The G1 board is either decoding or encoding, it can't do both at the same time. Most of the repeater conversions cut the changeover line so that the board stays in decode mode.   If you need both then you will need to add a separate encoder.
3) The brand of dip switch that GE used is notorious for not making contact the first time they are closed after being open for a while. If you place one of these boards in service and change the tone and it doesn't seem to "take", rock each individual switch that you changed a couple of dozen times or so and check the tone again.   In some cases you may end up changing the DIP switch.
Click here to see a photo showing where the Channel Guard boards are placed in the station.
GE made a proto-board, or perf-board, that was designed to plug into the control shelf. If you can find a source, you want to locate part number 19D417941G1. It's very useful - even if all you want to do is make up a paddle board for connecting external equipment to a base or repeater.

Mastr II Mobile Conversion Information:

Product Code file #61 - cracking the combination number on the standard Mastr II mobile housing      215 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "MC" or "MX". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your radio, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the mobile.
If your mobile radio is in a double-high housing (where the Combination Number starts with "EC", "EX", "EJ" or a "EY", sometimes called the "E" series) you will need Product Code file #65. Click here for a photo of an "E" housing.
If your mobile radio has dual front ends you will need Product Code file #69.
Step-By-Step GE Mastr II® Mobile Duplex Conversion      by Kevin Custer W3KKC
GE Mastr II® Mobile Conversion Information page      by Kevin Custer W3KKC
Custom Built Mastr II Mobile & Station Repeater Conversions      from Scott Zimmerman N3XCC
NHRC Repeater Controllers made just for the GE Mastr II      By NHRC, Simply plugs in!
GE Mastr II® Infosite      By Jeff Otterson, and NHRC     (offsite link)
Oscillator/Multiplier modification for the VHF Mastr II      A mod for improved 2 meter sensitivity by Jeff DePolo and Kevin Custer
FM'ing the Phase Modulated Mastr II      Converting the PM Mastr II to true FM Modulation by Jeff DePolo WN3A
Mastr II Mobile Power Amplifier considerations for reliability      Modifying the Mastr II PA by Ray Vaughan KD4BBM
GE Tech Memo on replacing the output transistors in a Mastr II UHF      By David Hopper WD4JKH
The elimination of spurious emmissions in early Mastr II VHF PA decks      By George Burton K7WWA
Mastr II UHF mobile modifications      By Paul Lorona KB6MIP (offsite link)
An informative writeup on GE Mastr II cables, with part numbers, and connector repair info
S.E.I.T.S.Mastr II Information      (offsite link)
WX7Y's Mastr II Duplex Modification      (offsite link)
W4XE's Mastr-Pro and Mastr II Information      (offsite link)
NW6H and WB6ZSU's Mastr II to TNC Connection Chart      (offsite link)

Mastr II Miscellaneous:

How to remove the second front end in a dual front end (DFE) mobile       By Scott Zimmerman   N3XCC
Painting a GE Mastr II Mobile With Paint That Almost Matches...      By Phil Heck  KE3EI
GE Mastr II PLL Highband Exciter Manual - LBI-30398      Courtesy David Hopper WD4JKH
Duplex Isolation Curves for highband TX with PM vs. PLL exciter (from GE)      provided by Jeff DePolo WN3A & Dave Karr KA9FUR
The Mastr-II Aux Receiver (LBI-30766L)      Includes the 19D417546G7 and G8 and antenna matching unit 19C321150G1 and G2   1.13 MB PDF file, 28 pages
Converting a Mastr-Exec II and a Mastr-II to 900 MHz      By Gene Colson W7UVH - a 10.5 MB PDF of a 7 page article from CQ VHF June 1999
Another scan of the 900 MHz Mastr-Exec II and Mastr-II article

Mastr II Highband to 220 MHz.Conversions:
A definitive guide to GE Mastr II 220 Rx conversions.      By M. Scott Zimmerman N3XCC
Conversion of Highband PLL Exciter to 222 MHz.      By Rob Mang K2ROB
WB6RHQ's Highband Mastr II to 222 Modifications      From Southern California's Condor Connection      (offsite link)
The Condor Connections Highband Mastr II to 220 MHz. Modifications      (offsite link)
An Excel spreadsheet to assist in crystal calculations for the 220 MHz MVP conversion
Complete Conversion of the Mastr II multiplier exciter and receiver to 222 MHz      By W4UWH      (offsite link)
How to modify a VHF UHS factory preamp for use in the 220 band        By Scott Zimmerman   N3XCC
Mastr II 220 MHz Repeater Conversions from Repeater Builder - the company      222 Mastr II conversions from Scott Zimmerman N3XCC

Mastr II Mobile Suppliers:
Hamblin Communications      Supplier of GE Mastr II mobile radios and parts

Mastr III Station Information:
Product Code file #SX - cracking the combination number on the standard Mastr III station      215 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "SXH" or "SXU". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your radio, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
The Mastr III Station programming cable is a straight-through DB9 serial cable. Connect either to the Data Port on the front of the repeater or the DB-9 connection on the rear of the interface board.
Thoughts on Mastr III to ham conversion      By Paul Robertson N2XZF
GE Mastr III Module Number Band Decoder Chart      By Matt Krick K3MK
Converting the GE VHF Mastr III 150-174 MHz Repeater to 144-148 MHz Amateur Operation      By Matt Krick K3MK
Converting the GE UHF Mastr III 403-430 MHz Repeater to 440-450 MHz Amateur Operation      By Matt Krick K3MK
Interfacing External Repeater Controllers to GE Mastr III Stations      Submitted by Matt Krick K3MK
Mastr-III Station Parts and Accessories Quick Reference Guide      A 1.7 MB PDF file submitted by Matt Krick K3MK

Mastr Executive II Information:
. Adding CTCSS (Channel Guard) encode/decode to the Mastr Exec II   By Stewart Rabinowitz KE5UT   56 kB PDF
. GE Mastr Exec II Modification and Information Site   By Ray Vaughan KD4BBM   (offsite link)
Product Code file #05 - cracking the combination number on the standard Mastr-Executive II station      102 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number starting with "FI" or "WI". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your radio, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
Exec II mobiles are covered by Product Code file #06       (Combination Numbers starting with "R" or "S" followed by "X" or "T" followed by "4" or"5").
High power Exec II mobiles are covered by Product Code file #13       (Combination Numbers starting with "R" or "S" followed by "X" or "T" followed by "6" or"7").
RCC and IMTS mobiles are coverd by Product Code file #18       (Combination Numbers starting with "CC", "XC", "YC", "CS", "XS" or "YS").
Exec II-based Mobile Repeaters are covered by Product Code File #82      (Combination Numbers starting with "MVR", "EVR", "DVR", or "RVR").
Mastr Exec II VHF mobile modifications      By Paul Lorona KB6MIP (offsite link)
Mastr Exec II UHF 40w Power Amplifier modifications      Improves operation in the 420-440 MHz range. By Harold Reasoner K5SXK. 135 kB PDF file. (Originally a powerpoint presentation.)
Exec II I-F alignment procedure      By Patrick M. Conway WA6JGM
IF alignment for Mastr II, Exec II, and Custom MVP radios.

Mastr Professional Information:

Product Code file #31 - cracking the combination number on the Mastr Pro mobile housing      250 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "M" or "S", followed by "T", "A", "E", "U" or "J". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your station, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
Product Code file #32 - cracking the combination number on the Mastr Pro Station cabinet      352 kB PDF
This is a "Rosetta Stone" document that will help you figure out what you have when you have a Combination Number that starts with "DM", "PM" or "VM". The first page is the translator for the combination number. The second page will help you determine which LBIs are the "top level" ones for your station, and from them you can find all the lower level LBIs. From those you can build up a complete manual identical to what was shipped with the station.
KA1OKQ's Modification of the Mastr Pro ER-41-C Receiver to 220 MHz
WB4TUR'sMastr Pro Page

Delta Information:
CAUTION:     DON'T LET THE SMOKE OUT !
The radios that preceeded the Delta and Rangr in the GE product line mostly used push-pull audio power amplifiers and audio output transformers, and drove the speakers as a hot wire to ground. The Delta, and many later radios eliminated the audio transformer and they run the the speaker as the push-pull load directly... both sides floating off of ground. This quirk is significant on your workbench: any audio test equipment that connects to the speaker (such as you would use to make a quieting measurement) must be on the far side of a audio isolation transformer. Motorola has a low-power one as part number SLN6435 in their test equipment catalog (being "test equipment", it's high priced - at about $80), and they also include a cheaper but higher audio power one in every tabletop base station (part number 25-80188B01, about $35 in late 2006) since common wireline remote controls expect ground-referenced audio to drive the remote sepakers. You can order either of the transformers separately, or you can get one from a web-based car stereo seller or at a local high-end car stereo shop (many dash-mount radios expect floating speakers, and many trunk mount audio amplifiers have gounded inputs). In a pinch you can connect a 2 watt resistor of any value from 8 to 22 ohms to the radio as a load, and use a 600 ohm to 600 ohm line transformer between the radio and the test equipment. Note that the audio bandpass characteristics of whatever isolation transformer you use will have to be wider than the audio frequencies you hope to pass through the radio.

In short, if you ground one of the Delta or Rangr speaker leads the odds are better than 75-25 that you will let some of the magic smoke out of your radio. So use an audio isolation transformer to prevent this - just put the transformer between the radio and any load that isn't a floating (an ungrounded) stand-alone speaker.

Note from WA6ILQ:
If you are looking to buy a "real" audio isolation transformer, check the car stereo shops in your area - sometimes they are marketed as "audio ground loop eliminators", or as "balanced to unbalanced adapters" - but look at them carefully as some are R-C networks, some are designed to work at millivolt levels - very limited as to the power level, and some are at 600 ohm impedance levels. You really want one that is at 8 ohms both in and out and can handle a watt or two of audio... (the audio level alone precludes using a transformer salvaged from a old modem or PC sound card). Always check the schematic - you want a transformer-based one that has no DC path from either input lead to either of the output leads.
You may already have something that will work - if your junk box includes two identical audio transformers that have an 8 ohm secondary (no matter what the primary is, as long as both transformers are identical) then you can use the pair to make a single substitute 8 ohm to 8 ohm audio isolation transformer. Just tie the primaries together and ignore them, then use the secondaries of the two transformers as if they were one 8 ohm to 8 ohm transformer.
And some times you can recycle something - the most flexible audio isolation transformer I ever found was an aircraft radio power transformer from the 1940s - the two separate 6.3 volt windings worked fine as 8 ohm windings, the primary 110/120 volt winding worked fine as a line level connection (as a source or destination), and the 400 Hz design worked just fine from 250 Hz to over 3500 Hz.
On the other hand, if you are just feeding a test meter (like for SINAD checks) or feeding the input of a repeater controller then you can get away with a non-1:1 transformer. I've had good luck with 600 Ohm-to-600 Ohm transformer (like a Triad TY145 - available from Mouser Electronics (p/n:553-TY145P) under $4 as I write this). I put one side across the radio speaker output leads with a 1 watt 8 ohm resistor as a speaker load with the other side of the transformer feeding the test equipment.

Another caution: The name "Delta" covers three different product lines, and all are different internally. The earliest "Delta" design is a crystal controlled design. Then the geniuses at GE came up with a synthesized design, and it was marketed as "Delta-S" - but it only covers about 2 or 3 MHz from highest to lowest frequency. Then they got a chance at a redesign and came up with the "Delta-SX" which can cover a range of about 37-38 MHz before the VCO falls out of lock - but it was made only for VHF and UHF - it was never made in a low band version. If you want a broad bandwidth radio on low band you need to find a Motorola "Syntor X" or "Syntor X9000" - they can cover from 28 to 54 MHz in one range (but the mobile antenna can't)... more details on those radios (and an antenna bandwidth workaround) on the Motorola pages.
When using the TQ2310 Suitcase Programmer (LBI-31229) to program Delta radios you need to refer to LBI-31263.

Anybody want to contribute a few Delta, Delta S, or Delta SX photos? (exterior and interior)
GE Delta Information by Dave Kaar KA9FUR      Converting and programming the Delta series radio      (offsite link)
More GE Delta Information      from a group of New England hams      (offsite link)

Rangr Information:
Anybody want to contribute a few photos? (exterior and interior)
Anyone what to do an overview article?
Converting the low-band GE Rangr to 6 meters      By Gary L. Peterson, NZ5V      (a work in progress)
When using the TQ2310 Suitcase Programmer (LBI-31229) to program Rangr radios refer to LBI-31630.

MLS and MLS-II Information:     (sometimes referred to as the MLS-1 and MLS-2)
There is a yahoogroup oriented towards the MLS at http://groups.yahoo.com/group/GE_MLS.   Note that it's "GE(underscore)MLS".
An Overview of the MLS Mobile Radio by Robert Meister WA1MIK.
Comparison with the GE MLS-II models. Photos, features, etc. Please read the MLS-II Overview (below) first.
An Overview of the MLS-II Mobile Radio by Robert Meister WA1MIK.
Model numbers, comparison with the Motorola MaxTrac radios, photos, features, etc.
Replacing MLS-II Mobile Radio Power Supply Caps by Robert Meister WA1MIK.
If your radio has an annoying 100 Hz hum coming out of the speaker, this may be the fix for it.
TQ-3342 Programming Software Guide
This is the instruction manual for the MLS-II programming software, direct from Ericsson.
The MLS was a synthesized mobile that used a PROM chip to hold the frequency information. Programming the PROM chip takes specialized equipment that is not too common. Anybody want to do a programming article?
The MLS-II is programmed by PC software, a RIB, and a connection cable. Anybody want to do a programming article?

Repeater-Builder does not have any programming software. It can probably be found "out there" on the web; better yet, ask on the the GE mailing list.

From a private email:   GE had a problem with electrolytic capacitors failing and leaking, especially in mobiles in hot parts of the country (like southern Texas in the summer). Many GE mobiles (including the MLS series) had several electrolytic capacitors on the sloping front panel boards. When these leaked the corrosive electrolyte would eat up the copper traces, including the copper plating in the pass-through holes in the PC boards (the plating in the holes was too thin). In most cases the boards were just replaced. The traces on the boards could be repaired with 30 or 32 gauge wire soldered onto what was left of the traces but the only cure for the holes was to insert a piece of thin wire in each plated hole and solder both sides. When you replace the caps you will probably want to use caps with a a higher temperature rating.

MPD Information:
The MPD came out around 1984 and was dropped around 1989.
Anybody want to contribute a few photos? (exterior and interior)
Anybody want to contribute some information on the series?

MPA Information:
The MPA came out around 1988 or 1989 and was dropped in 1996. It was the successor to the MPD. It is a programmable radio.
There is a yahoogroup oriented towards the MPA at http://groups.yahoo.com/group/GE-MPA.   Note that it's "GE(hyphen or dash)MPA".
Anybody want to contribute a few photos? (exterior and interior) and some information on the series?
How to Use the M-PA Radios on the 902-928 MHz Amateur Band   168 kB PDF   By: Mark A. Cobbeldick KB4CVN
This is a compellation of the experiences of long-term efforts by several hams, including: Doug Bade KD8B (Creator of the modified software to support 902-928 MHz and dozens of hours of testing), Gary Peterson NZ5V (Reviewing the data and testing methods) and John Belstner W9EN. This information applies equally to the following radios: M-PA, MTL & P400. The GeNet 900 model of the MTL is not supported due to the modem/clock differences.

MR-K Information:
Anybody want to contribute a few photos? (exterior and interior) and some information on the MR-K series?
A schematic of the MR-K programming cable   26.1 kB GIF

MVS Information:       Front panel photo   257 kB JPG
Anybody want to contribute a few more photos? (exterior and interior)
Most of the MVS radios "out there" have 16 channels. Some have only 2, and a very few have 128.
The MVS uses the TQ-3310/TQ-3370 programming interface (RIB) and the TQ3315 (p/n 19B801417P4) programming cable, and programs through the microphone jack.
There is very little MVS information in amateur radio circles - anybody want to write a programming article?
Repeater-Builder does not have any programming software. It can probably be found "out there" on the web; or better yet, ask on the GE mailing list.
The MVS implements the tone squelch mic clip hangup feature by using a microphone that has a reed switch mounted inside the back of the microphone case, and a permanent magnet mounted in the GE-supplied mic clip that is mounted on the dashboard. When the user lifted the microphone out of the clip the reed switch changes the receiver mode from CG mode to carrier squelch mode. The microphone clips with the built-in magnets are almost impossible to find in the second-hand marketplace. Some have had luck making a hangup clip with a magnet. Others have added a slide switch to the microphone case. Fortunately you can disable the hangup feature in the programming software.
The LBI sections you will need to build the manual for your MVS will depend on if you are a user or a maintainer and if it is VHF or UHF. The list below is in LBI number sequence. Users will need only #7. Bench techs will need numbers 4, 5, 12 and 15 plus 1, 2, 3, and 6 for VHF, and 8, 8, 9, 10 and 11 for UHF. Remote mount (i.e. trunk mount) radios will need #13 added to the list. Desktop bases will need #14 added.
  1. LBI-31919E   1.5 MB   High band 40 watt MVS maintenance manual
  2. LBI-31920D   625 kB   High band RF board 19D901835G1 (136-153 MHz), G2 (150-174 MHz)
  3. LBI-31921C   126 kB   High band Power Amplifier board 19C851540G1 (136-153 MHz), 9C851540G2 (150-174 MHz)
  4. LBI-31922D   630 kB   Audio board 19D901870G1
  5. LBI-31924F   1.15 MB   MDR, MTD, MVS, TMX-8825 System Board 19D901891G1
  6. LBI-31926C   193 kB   Service section for high band combinations
  7. LBI-31927D   MVS - Operators manual   Covers 2 channel, 8 or 16 channel, scan, selective calling (SelCal) and PA operation
  8. LBI-31932F   421 kB   UHF 25 watt MVS maintenance manual
  9. LBI-31934C   1.1 MB   UHF power amplifier board 19C851617G1 (403-440 MHz), G2 (440-470 MHz) or G3 (470-512 MHZ)
  10. LBI-38258D   637 kB   MVS UHF RF Board
  11. LBI-38292   205 kB   Service Section for UHF MVS combinations
  12. LBI-38387B   374 kB   MVS Front cap assembly 19D901913G1 (this is the front panel)
  13. LBI-38465B   388 kB   Remote mount option 19A705306G3
  14. LBI-38635D   1.6 MB   MVS, TMX or MTD Desktop Station
  15. LBI-38899   285 kB   MVS / MCS / TMX-8712 / TMX-8310 Logic boards 19D901690G11
There is another front cap LBI that we do not have- LBI-31925. If anyone has it we'd appreciate a scan, or an opportunity to scan it.
VE3FYN has some information here. The manual he offers for download is the LBI-31919E manual above.
KD4BBM has some notes on the MVS as well.
Ralph Hogan W4XE has some good MVS notes, some photos, interfacing information and pointers.
Converting a VHF MVS radio to 220 MHz      by Matt Krick K3MK. This is a 7.5 MB PDF file.
A few notes on programming the MVS:
If your turn on a new-to-you radio and get an E0 error that means that the receive synthesizer is unlocked. An E1 error indicates the radio is not programmed. Both can be caused by a missing (or blank EEPROM - it may have to do with which fault the CPU catches first. Many used radios have been found with missing EEPROM chips - the right way to deprogram a radio so the new owner can't just plug and play is to over-write the department frequencies with new channels programmed as receive only (likely candidates are the 7 weather channels for VHF, or the FRS channels (receive only) for UHF).

An E3 error indicates no communication with the front control panel.

All of the error codes are defined in LBI-31926.

The programming software is a DOS application and you will need real DOS (or the DOS side of Win 95/98/ME), a real serial port and a TQ-3370 or P-96-A MVS programming cable. I believe that the cable can be made from an old IDE hard drive cable. The software comes in versions versions 1.1, 2.2 and 3.0. Once you program a radio with a higher version you can't go back to the older version.

Each channel will have entries for TX, RX, CG TX, CG RX, STE TX and CCT.
This translates to transmit RF frequency, receive RF frequency, transmit tone frequency, receive tone frequency, STE (y/n), and a numeric value for CCT.

STE means Squelch Tail Eliminator. Turning it on causes the transmitter tone encoder to invert the phase of the tone when you release the PTT, and keeps the transmitter on the air for about 100-200 mS. This mutes the receiver audio on the other end BEFORE your transmitter goes off the air, resulting in no squelch tail (some folks call it the squelch crash). Motorola calls this same system "reverse burst". It's EXTREMELY rare that you would want to turn STE TX off.

CCT is the Carrier Control Timer which is GEs name for the transmitter timeout timer. It turns the MVS transmitter off after a certain period, which is normally set between 60 and 90 seconds. This prevents locked-up repeaters and cooked mobile transmitters when (not if, when) the user sits on the microphone.
A few notes on the MVS firmware, from a comment thread on the the GE mailing list:
If you end up with a MVS that was "deprogrammed" by pulling the wront chip (the firmware chip instead of the EEPROm chip) you will need to get a new formware chip. The older logic boards use the 87C64-20 chips and the newer logic boards use the 87C257 chip. The firmware images are "out there". The funny thing is that if the EEPROM is still there, once the firmware PROM is put back in one of these "depreogrammed" radios it will come back working on the original frequencies programmed and on the last channel and volume setting selected.

Century II Information:
Anybody want to contribute a few photos? (exterior and interior)
Anyone what to do an overview article?
 GE Century II highband to 2 meter conversion      Converting the highband Century II to the 2 meter ham band

Custom MVP:
The Custom MVP (commonly called the MVP) is essentially a dash-mount low power Mastr II.

Step By Step GE Custom MVP Conversion Site:      By Kevin Custer W3KKC
GE MVP Bandsplit Modification      By Matt Lechliter   W6KGB
MVP to Repeater Conversion      By Bob Dengler NO6B
Installation instructions for Parkinson RP3A Repeater-Controller with GE UHF MVP mobile radio   580 kB PDF file.
WB6RFW's GE MVP Radio Modifications
A VHF MVP/Exec II 222 MHz Conversion      From Southern California's Condor Connection
UHF MVP TX and RX Tuning Instructions      By Bob Dengler NO6B
Tune Up Instructions for the MVP and EXEC II     VHF Receiver   and   VHF Exciter   and   UHF Exciter
Custom MVP I-F alignment procedure      By Patrick M. Conway WA6JGM
IF alignment for Mastr II, Exec II, and Custom MVP radios.
Some GE MVPs have shown up with a controller board made by Parkinson inside the case.
The system manual is LBI-3772, the board manual is LBI-32792 and both can be found in the LBI master index at this web site.
Custom MVP Mobile Repeater Conversions from Scott Zimmerman N3XCC     GE conversions from Repeater Builder (the company).
Temperature Compensation Capacitor information for 5C ICOMS      13 kB PDF   provided by Chuck WB2EDV
Converting a UHF 20/35w PA to 5 watts for link transmitter use      By Doug Crompton WA3DSP
Regarding UHF units: While there are duplex conversions of the MVP that will enable its use as a repeater or as a link radio, please understand that the MVP was designed as a 5, 20 or 35w mobile, and was designed for an intermittent duty. The 35w version has all three RF power amplifier stages (the pre-driver, driver and final), the 20w has two (the pre-driver and the driver), and the 5w has only one stage (the pre-driver). A common modification is to take a heat sink intended for a P4 CPU and adapt it to the back of the radio. Even the driver transistor gets hot and needs additional heat sinking. So if you intend to run an MVP with any kind of duty cycle (i.e. as a link or as a repeater) you really need a heat sink with a fan. And use a real metal ball bearing fan, not a sleeve or bushing fan.

Monogram Information:
Programming the Monogram and Maxon mobile radios      By Scott Lichtsinn KBØNLY
We have zero info on the Monogram series other than at least one of them was a rebranded Maxon SM4000 series radio. If you have one of these then look on the web for the Maxon SM4000 series information and programming software.
However, the following LBIs cover the mobile radios (they are all on this site):
Operators Manual: LBI-38862A
VHF Maintenance Manual: LBI-38864B
UHF Maintenance Manual: LBI-38865A
If anyone has any other Monogram information and the software we'll be happy to host it (assuming it's legal to do so).

PCS Information:
Anyone want to do an overview article?
Converting a VHF PCS radio to 220 MHz      by Matt Krick K3MK. This is a 2 MB PDF file.

Phoenix and Phoenix SX:
Anyone want to do an overview article?
The screws that are used to hold the mounting bracket to the radio housing are metric, M4-0.7x10, which translates to M4 diameter, 0.7mm thread pitch and 10mm (1cm) long. Thanks to Tedd Doda, VE3TJD for the info.
Phoenix 2 channel to 16 channel modification      By Joel Huntley WA1ZYX      (offsite link)
Interfacing the Phoenix to a packet TNC   offsite link to an article by Ray Vaughan KD4BBM
While the particle is packet oriented the info will be useful to anyone that needs to interface a Phoenix to a repeater controller - as a control receiver, point-to-point link, remote base, whatever.
KG4LNE's Phoenix Resources Page      By Robert Starr KG4LNE      (offsite link)
When using the TQ2310 Suitcase Programmer (LBI-31229) to program Phoenix radios refer to LBI-31262.

Frequency Agile Modifications for Commercial Radios
Modifying the S990 head for direct frequency entry      By David Hopper WD4JKH        (offsite link)
       The 9xx heads will work with all Delta S, Delta SX and Ranger series radios.

Trivia, Miscellaneous Information, and Datasheets:
GE Mastr Trivia Question      By Mark A. Cobbeldick KB4CVN

Shure 890TT mobile DTMF microphone Also goes by M/A-Com model numbers 344A4611P1, KRY1011637/3, KRY1011654/10. Possibly for the Orion product line. Submitted by A. Nony Mous (950 kB PDF file)

Radio Service Training Seminar (1969) General procedures for testing and measuring mobile radio performance. While primarily aimed at older (tube) equipment, the techniques are equally useful for today's modern radios. Submitted by A. Nony Mous (917 kB PDF file)

GE C800 and C900 Control Heads Sales Brochure   for Mastr II and Executive II Mobile Radios. 6.4 MB PDF file. 1977 vintage.
GE Mastr Executive II Sales Brochure and Specs   6.7 MB PDF file. 1978 vintage.
GE Mastr Base Station and Control Equipment Sales Brochure   3.9 MB PDF file. 1978 vintage.
GE Mastr Executive II VHF Base Station Specs   2.1 MB PDF file. 1978 vintage.
GE Power Call and Power Call/Siren Sales Brochure and Specs   2.5 MB PDF file. 1977 vintage.
GE Mastr Remote Control Consoles Sales Brochures and Specs   Includes Tone and DC remotes, DESKON II, and Command Control Centers. 17 MB PDF file. 1978 vintage.
GE Mastr PE Personal Radio Sales Brochures, Part 1 of 2   Includes MPR, MVP, Porta-Mobile II, and accessories. 3.1 MB PDF file. 1979 vintage.
GE Mastr PE Personal Radio Sales Brochures, Part 2 of 2   Includes Mastr Personal, Mastr MVP Personal, Accessories, POWR Mastr add-on power amplifiers, MPR Personal. 3.2 MB PDF file. 1979 vintage.
GE Mastr II mobile radios Sales Brochure and Specs   Includes Mastr II M, Mastr II E. 11 MB PDF file. 1978 vintage.
GE Mastr II repeater and base stations Sales Brochure and Specs   Includes Mastr II M, Mastr II E. 6 MB PDF file. 1978 vintage.

Test Sets and Tuning Tools

Information on GE Test Sets and Tuning Tools



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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.