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General Electric / Ericsson / Com-Net

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For quick access to model-specific information use these in-page jumps:
      GE Mastr II Mobile and Station       GE Mastr II Station       GE Mastr II Mobile       GE Mastr III Station
Mobile Suppliers     Exec II Info      Mastr-Pro     Delta      Rangr      MLS       220 MHz Conversions
Century II       Custom MVP       Monogram       Phoenix & Phoenix SX       EX3 Test Set
DIP-Switch CG Board       Frequency Agility       Technical Info, LBI's & Manuals       Trivia & Misc.

We have zero information on the GE Mastr IIe or III series - would
someone like to write an article or two on them?

GE Mastr II Mobile and Station Conversion Information:

GE Crystal Information   A 12 page PDF file about 500kb, 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)
A schematic of the exciter audio "blob"     Donated by A. Nony Mous
A Mastr II S-Meter Circuit     By Andy Kadvan KA8R from ACC notes
A crystal frequency calculator for the Mastr II     By 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      By Matt Lechliter W6KGB
Help!! My UHF Mastr II self quiets after conversion     By M. Scott Zimmerman N3XCC      new
Help, my Mastr II® has lost receiver sensitivity!      Some Mastr II front end helical castings grow internal whiskers and short themselves out
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.
Tuning Tools: A while back there was a question on the GE Mastr II mailing list about which tuning tool(s) were the best for working on Mastr IIs and MVPs. Eric Lemmon WB6FLY responded with: "All of the tuning adjustments on the Mastr II are handled by the Micor "Universal Tuning Tool" part number 6684387C01, currently priced at about $5.50 from Motorola Parts. This handy tool has a thin steel blade on one end that mates with the ICOM and front-end capacitors, and both 0.075" and 0.100" hex drives on the other end. Most coils on Mastr II radios require the 0.075" tool, but a few coils on the RF assembly require the 0.100" tool. The body of the Micor tuning tool is large enough to get a good grip, making it easy to make very small adjustments. Overall, it's a must-have tool !

GE Mastr II Station Conversion Information:

Mastr II Station to Repeater Conversion      By Don Woodward  KD4APP
How to add a PTT disable switch to a GE 10v/Station Control Module      By M. Scott Zimmerman N3XCC     
Pion & Simon Electronics      Mastr II Station Controllers that plug right in!     
Mastr II Station to ACC 850 Repeater Controller      3.15 Mb PDF file by ACC
SCOM 7K Controller Connections to Mastr II      An off-site link to a PDF at the Scom web site - Scroll down to the "Getting the most from your S-COM products" section
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.
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

GE Mastr II Mobile Conversion Information:

Step-By-StepGE Mastr II® Mobile Conversion Site and other Mastr II information
CustomBuilt Mastr II Mobile & Station Repeater Conversions      from Kevin Custer and Scott Zimmerman
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
GE Mastr II® Conversion Site      MastrII and Mastr Exec II site by Bob Walchli N8ZCC      (offsite link)
KD4APP's Mastr II mobile to a repeater modification      (offsite link)
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)

GE Mastr II Misc:

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 De Polo, WN3A
The Master-II Aux Receiver (LBI-30766L)      19D417546G7 and G8 and antenna matching unit 19C321150G1 and G2   1.13mbpdf file, 28 pages
Converting a Mastr-Exec II and a Mastr-II to 900mhz      By Gene Colson W7UVH - a 10.5mb PDF of a 7 page article from CQ VHF June 1999
Another scan of the 900 MHz Mastr-Exec II and Mastr-II article
The GE Mastr II email list server      For people seeking information on GE Mastr II's

GE Mastr II Highband to 220 MHz.Conversions:
A definitive guide to GE Mastr II 220 Rx conversions.      By M. Scott Zimmerman N3XCC     
Conversionof 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)
Excelspreadsheet to assist in crystal calculations for the 220 Mhz. MVP conversion
CompleteConversion of Mastr II multiplier exciter and receiver to 222 MHz.      By W4UWH      (offsite link)
How to modify a VHF UHS preamp for use in the 220 band.        By Scott Zimmerman   N3XCC     
Mastr II 220 Repeater Conversions from Repeater Builder      222Mastr II conversions from Scott Zimmerman - Kevin Custer
GE Mastr II Mobile Suppliers:
Hamblin Communications      Supplier of GE Mastr II mobile radios and parts
GE Mastr III Station Information:
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 1.7MB PDF file submitted by Matt Krick K3MK
The Mastr III Station programming cable is a straight-through DB9 serial cable.
GE Mastr Executive II Information:
The"Mastr Index" of Exec II Information
GE Mastr Professional Information:
KA1OKQ'sMastr Pro ER-41-C Receiver to 220 MHz Modification
WB4TUR'sMastr Pro Page
GE 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 PA decks 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 3.2 ohm or 8 ohm 1:1 audio transformer.   You can get one from most any 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 grounded inputs).   In a pinch you can put a 2 watt resistor of any value from 8 to 22 ohms on 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 that isolation transformer 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 speaker leads 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 an ungrounded stand-alone speaker.

GE Delta Information by Dave Kaar KA9FUR      Converting and programming the Delta series radio      (offsitelink)
More GE Delta Information      from a group of New England hams      (offsitelink)
    When using the TQ2310 Suitcase Programmer (LBI-31229) to program Delta radios refer to LBI-31263
GE Rangr Information:
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
GE MLS Information:
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. The MLS II is programmed by PC software and a connection cable. If anyone wants to do an overview article on the MLS and the MLS II radios please let us know.
GE Century II Information:
GE Century II highband to 2 meter conversion      Converting the highband Century II to the 2 meter ham band
GE Custom MVP:
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
WB6RFW's GE MVP Radio Modifications
A VHF MVP/Exec II 222 MHz Conversion      From Southern California's Condor Connection
KC7GSA'sTune Up Instructions for the VHF MVP and EXEC II     Receiver    and   Transmitter
MVP Connectors and Pin kits for Sale from Eric Homa N6NMZ
The Manual on the Parkinson controller that fits inside the GE MVP
      The system manual is LBI 3772, the board manual is LBI32792 and both can be found in the LBI master index.
Custom MVP Mobile Repeater Conversions from Kevin Custer W3KKC      GE conversions from the author of this site
Temperature Compensation Capacitor information for 5C ICOMS      13kb PDF   provided by Chuck WB2EDV
GE Monogram Information:
The Monogram was a rebranded Maxon SM4000 series radio. Look on the web for the Maxon SM4000 series information and programming software.
If anyone has the information and the software we'll be happy to host it (assuming it's legal to do so).
Phoenix and Phoenix SX:
Phoenix 2 channel to 16 channel modification      By Joel Huntley WA1ZYX      (offsite link)
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
The Standard GE Test Set
This is the manual for the 4EX3A-11 standard GE test set - LBI-4454 Version B
Additionally, here are the schematics for the metering cables for various radios:
Porta Mobile, Mastr-Pro and Exec     74 kb
Mastr II, Exec II and MVP     68 kb
Delta mobile     84 kb
Metering cables parts list    40kb
With the information from the above LBI you could design a metering cable for almost any radio... even a Micor.
The 10-bit dip-switch style Mastr-II Channel Guard board
This is the manual for the 19D432500G1 / G2 / G3 standard CG board - LBI-31056 Version G
Additionally, as a shortcut, here is the tone table (see the lower right corner)     123kb (note that "X"-marked bits are open switches!)
Notes:
1) The G1 board is the encode-decode board,theG2 is encode-only, G3 is decode-only.
2) The brand of dip switch that GE used is proneto not making contact the first time they are closed after being open fora 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 a couple of dozen times or so and check the tone again.
GE Frequency Agile Modifications for Commercial Radios
GE Phoenix, Rangr, Delta, and Ramsey FX Series      By Joe Burch K3JLS        (offsite link)
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.
GE Technical Information:
Currently stocked manuals can be ordered from the M/A-COM Customer Care Center at 800-368-3277 or call Publications directly at 434-832-6592.
The "Mastr" list of LBIs      Over 1.6 gigabytes of free downloadable PDF'd GE Tech Manuals (the index alone is over 70 pages)
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
GEManuals from Ted Jansen      A good source for original GE manuals
GE Duplex Operation Curves      from Dave Kaar KA9FUR      Curves that show how much isolation is needed for different GE Station configurations
GE Trivia & Miscellaneous Information:
GE Mastr Trivia Question      By Mark A. Cobbeldick KB4CVN

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Mastr II® is a registered trademark of Ericsson/Com-Net Inc.     GE / Ericsson image used with permission.

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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.