This is a low band split GE Mastr II station conversion for use in the ham band. The receiver has been modified. The 4EX3A-11 standard test set and a Simpson 260. LBI's are being accumulated and read.

The current repeater is / was a S3D040TFURB

S3 = Mastr II

D = 30" Desk Mate

040 = 40 Watts

T = Tone Remote

F = 4/4 TX-RX Frequency number

U = CG Channel Guard

R = 406-420 (front end modified for 444 use)




February 20 - 23rd, 2009

Had some help moving the completed repeater project in place and ran into issues that required a consultation phone call for tech support, thank you N9QIP, available and helpful as always.

The DTMF tones 1-3 are not working and others are marginal. The CTCSS tone decode is functional, the encode is not. I have some ideas but if you care to share some others, send them over. A VA3TO interface has been purchased to utilize an external DTMF decoder. After using IRLP and experiencing 100% reliability and function with their board, an external seems like logical course of action.

The cabinet is now an old Motorola 72 inch, the main repeater is a re-aligned and tuned low split UHF Mastr II brought up into the ham band. FSJ4-50B hardline is on all transmit lines and some RG400 is still in the receive side but will be changed for FSJ1-50A.

Preamp testing with Angle Linear units needs to be done (ARR is installed for now).

Duplexer analysis and tuning: the current 526-4-2 unit is within spec but has not been checked with the pass cans attached (used an IFR A-7550 with an Eagle return loss bridge).

Transmission line analysis was not done (7/8's Heliax) and the antenna review was not done (DB413 favoring an Easterly direction).

APRS IGATE seems to be working well although the Diamond antenna has been in the air for a long time. The antenna has endured many winters of ice and wind and has never failed but it is looking worn. Need to test the cable (LDF4-50) and antenna.


The original lead for an external controller has been replaced with a new one, shielded.


Audios on the GE were very hot into the controller and both from and to Echolink. Resistors on the input and output audio lines brought them to the correct levels. Interesting thing as all the audios on every set up have required us to leave them wide open, this is the first one I ever had to reduce. Very nice having some margin to work with.

Heliax SuperFlex is fun to work with and the ends are nice to install. 

April 2009

The Vocom PA has been disconnected and a 100 watt GE PA installed on the Mastr II unit. The Astron power supply failed and has been replaced with a GE unit that has a  battery back up option. Battery back up was tested and works well but no idea how long the two deep cycle units will maintain operations. No inverter on the system so the computer will go down on a power outage.

Motorola 6' cabinet, original meters not connected but they fill the space above the door and may be used in the future. Two cool lights, one for power and one for transmit should be easy to connect. Not sure about the milli-something meters. If you don't have a source, I have 2553 keys if you need them - $3 each plus shipping.

PK-88 TNC, IBM computer - APRS, Echolink and server storage, light on next to the Kenwood repeater is for the Echolink keying, TKR-820 - maybe for GMRS, Maxtrac low-split 25 watt VHF for APRS, MCC RC-1000 controller, GE MastrII Uhf repeater, two Motorola 1507 pass cans and DC wiring, RFS 526-4-2 duplexer, Vocom UHF amplifier - offline, Geist surge protector and 120 volt power strip, GE Power Supply

IDA controller, Repeater Drawer

Back of the repeater - PK-88 TNC, IBM computer

TKR-820, Maxtrac

RC-1000, GE Mastr II with IDA controller, ( low power PA-for the Vocom now removed), High Power GE PA is now installed - 100 watt

IDA Controller and J1200 Connections for an external controller, trouble with DTMF tones so the audio connection is not recommended until it is figured out

IDA: LBI-31807D, there are others I believe

ARR preamp, RFS duplexer, Motorola pass cans

Vocom power amplifier - not in use and (Astron now removed)

 GE power supply, Batteries and Charger for Back Up power

May-June-July 2009

Installed the VA3TO interface, zero DTMF decode. Worked with the internal DTMF decoder on Echolink enough to get 3-9 most of the time but it is hit or miss. Then, I did something to the controller to make the tail beep go away and Echolink audio to not pass one direction. Sent the RC-1000 to Ron at MCC in Florida, he checked it over and there isn't anything wrong. He reprogrammed the unit and it was reinstalled by N9QIP and AB9NS. The controller connects via a DB25 connector a std coaxial power plug.

The VA3TO did key and unkey and pass audios correctly. It did hear one or two DTMF tones, usually 1 or 3 but nothing else. I will play with it some more and try to figure out why the DTMF tones are being so difficult to decode, maybe one I have that figured out both the internal and external DTMF will work correctly and I can not use the interface. The system loses a bit of the Echotime features using the interface.

Might go away from the IDA controller the next round of repeater change outs. I did find good interface connection information so we'll see. A carded unit could be set up that has encode, decode and PLL using the large ICOM. The ICOMS were sent to ICM to be recrystalled and compensated. The new ICOMS are 2PPM units, some pictures are on the 444.675 page already.

Anyone have their favorite external controller and Echolink connection points for the standard Mastr II? I emailed no less than 10 Mastr II owners and posted on some popular groups inquiring about how to interface an external controller to a Mastr II, guess how many response were received, 3! I post and share about radio but there are a lot of Mastr II owners that either don't know how to wire their own units or were not willing to share the information.

Another option for the station is to change the unit over to an EchoIRLP, very intriguing and I like the idea of working with CentOs.

After reading stories of the Mastr II units going out due to a bad match, and this PA not having a Z match, a new Telewave was ordered and installed.

July 2009

Possible future repeater is a SC74VAV88D if I can't figure out the IDA controller interfacing, looks like a nice machine

S = Mastr II 44" Desk Mate

C = Continuous

7 = 66-128 Watts

5 = 25 KHz

V = Tone Remote / Repeat

A = 1/1 TX-RX Frequency

V = DCG Duplex & Channel Guard

88 = 450-470

D = UHF PLL .0002% Sweet!


Model and ID tag, RF shelf cover, Repeater front, Repeater cars

RF deck, RF deck, Encode, Decoder?

UHF PLL exciter, 2PPM ICOM, PLL board, Power supply

ICOMS were sent to ICM for re-cry$talling and compen$ation.

See the Equipment Page for another repeater from this lot.


December 2009

The IDA controller Mastr II is still in place.

An Arcom 210 controller has been installed in place of the RC-1000. The controller has three ports, one is used for the UHF repeater and one for the link for now. The other port will go to either another repeater or a VOIP service (IRLP, EchoIRLP).

The autopatch (not connected) and audio delay for two ports (bypassed because it isn't working correctly). There are many programmable features and more programming will be done over the next few visits or when a serial port card can be added to the Echolink/APRS computer (serial ports all in use).

Link radio (GE MLS), APRS radio (low split VHF Maxtrac) and Arcom 210 controller from the front in the two left pictures, and back in the middle and fourth pictures, IDA controller J1200 with controller and transmit light connections in the far right picture. The GE link radio and Mastr II power amplifier cooling fans are triggered by a ground signal from the controller through a 4N33 opto-isolator, TIP121 transistor and an Omron relay (all from Mouser) as seen on the left side in the second picture from the right.

The repeater is now linked into the WINetwork (this is a large system, please allow extra time between key up and talking and extra time for the system to drop). The RF link between Coloma/Hancock is using an M2 440-18 from AES with just a bit of noise on the signal.

The original lights in the repeater cabinet were removed and replaced with LED's and resistors courtesy of KD4RAA (thanks Danny). The Power light is wired to the GE repeater power and the Transmit light is wired to the antenna relay via a 4N33 and 2N3906, both work great. The 4N33's are being pulled low on the ground side and the positive side with a 4.7K to the system voltage (14.8 idle, 13.5 in transmit)


The repeater sounds very good locally but still needs a thorough check including duplexer fine tuning, pass band cavities and cabling.

Cannot get the DTMF tones to decode. The Arcom LED's do indicate that DTMF's are being received and the controller mutes and cover tones them. The wiring was tried from its current J1200 location and from the receiver directly (the Arcom has a built in de-emphasis circuit), but still didn't decode. So far it seems that the GE with the IDA controller will not allow DTMF tones to decode for some reason. Emails have been sent to numerous GE Mastr II repeater owners and the responses have usually pointed to another site's work but none of their connection hints have worked out so far. Either the audio connection is so simple that no one thinks it needs explanation or it is so complex that no one can explain it, either way, this repeater is still not decoding DTMF tones. Very frustrating with all the trips, time and money spent and still no positive results. Will send out some more inquiries in the hope of finding an answer.

When I figure out how the controller must be fed from the GE, the information will be clearly posted for anyone else that would like to read and learn how to accomplish the feat.


Heliax is beautiful.

FSJ4-50B is used for all transmit lines. FSJ1-50A is used on part of the receive lines that will all go be Heliax eventually.

Any thoughts about the station, please email aa9nv at arrl dot net,

Thank you very much.


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This is a complaining story about a bad business transaction, not a must read but it was nice to get it off my chest.

Three of the IDA controller Mastr II units were originally purchased as crystalled, tuned and wired units ready for Amateur Radio use on the UHF band. The .100 and .475 came in as fair to good units both operationally and cosmetically so I ordered a third unit from the same person with specific and agreed to additional requests regarding condition and performance. The .675 arrived with great expectation but rapidly turned out to be a huge disappointment as a beat up, dirty, and non-functioning unit. The unit was dented, filthy and non-functional in all but basic power to the exciter and receiver but even then, the tuning was off. The receiver and exciter were still alive thank goodness so I pulled them out and put them in what was supposed to be the .475 repeater in order to have a good working .675 unit. I probably should have retuned the .475 exciter and receiver with the .675 channel elements looking back on all the changeover and retuning work that had to be done anyway. The extra IDA controller that shipped with the original .675 unit should have been my first clue as to the multitude of problems to come but even with the controller change out, nothing worked.

While cannibalizing the units was never the intent, neither was spending a fortune on a pile of beat up junk, non-working parts and many hours of extra labor trouble shooting and changing out components. Buyers beware, even if you purchase one or two good units and even if the seller is another Amateur as yourself, you still run the risk of getting took for a lot of money. It isn't right to do people like this so please don't. This type of unethical and immoral activity soils the reputation of  Amateurs and the hobby.