GE MASTR II Repeater

[n4gix]

I just bought a full-sized GE MASTR II repeater for $199.99. If nothing else, the two power supplies and two 100 watt continuous duty Class C amplifiers are worth far more than the entire unit, so I don't think I got a bad deal...

 

I already have a Decibel DB4076W-A copper duplexer that should work well with this.

This is the high power version of the GE MASTR II repeater, it has the typical rack mountable MASTR II with two additional RF power amplifiers and power supplies. The Combination Number is VCS5TAD88B. The repeater is currently on 454.650 R / 459.650 T, and was used for a short time as a GMRS repeater. The RF output was recently measured at 160 watts continuous output.This is a large floor mounted cabinet that measures 69" H, 23" W, 21" D, weight is 400 lbs. Operates from 120 VAC single phase power.

Now I just need to make arrangements for a friend to drive me up to Milwaukee in his pickup truck to haul this H U G E monster back down to Hammond, Indiana.

http://puu.sh/r5Csw.jpghttp://puu.sh/r5Cug.jpghttp://puu.sh/r5Cvk.jpg

[WQYC236]

WOW, what a deal! Now if you could only find a mountain somewhere in Indiana ,  (I grew up 20 miles south of Ft. Wayne, IN)

[PastorGary]

Courtesy reminder for all MyGMRS members:  47CFR95.135 (a) -

 

§95.135   Maximum authorized transmitting power.

(a) No station may transmit with more than 50 watts output power.

[n4gix]

WOW, what a deal! Now if you could only find a mountain somewhere in Indiana ,  (I grew up 20 miles south of Ft. Wayne, IN)

My plan is to part out one of the amplifiers and power supplies on eBay to recoup the investment, then throttle the power back on the exciter to limit the output to 50 watts. With the massive heat sinks and fans, it should just loaf along...

[WQYC236]

That is going to be one cool machine.  How did you find it?

[n4gix]

That is going to be one cool machine.  How did you find it?

eBay... It's been listed and relisted for the past seven months, so I just threw in my first bid of $199.99 and was the "winner" so to speak.

 

They tell me they have another one just like it for sale. I'll take a look at it while I up there and maybe buy that one as well since I'll already be there with a pickup truck.

[quarterwave]

These were nice stations, base or repeater. In their day had better audio than Motorola. The trick will be getting the amplifier down to 50 watts and stable. Sometimes the high power amps have trouble running at 50% or less rated power. 

[n4gix]

These were nice stations, base or repeater. In their day had better audio than Motorola. The trick will be getting the amplifier down to 50 watts and stable. Sometimes the high power amps have trouble running at 50% or less rated power.

The TX/RX deck itself has a PA capable of 40 to 50 watts all by itself. I plan however to remove one of the pair of amps and power supplies and drive the remaining amp with less power from the deck's RF amp.

[zap]

Reminds me of a DPS surplus Mastr Pro in Lubbock. Dual receivers, 200W out on low band…

 

 

Sent from my iPhone using Tapatalk

[n4gix]

Based on the frequency pair, this repeater was used for UHF IMTS service on channel QF.

[quarterwave]

I saw alot of these stations back in the early 90's...I'm vearing off topic here....

 

The sheriff's department where I live had a Motorola Micor station that was their 39.58 receiver (and backup TX), but it was dual receive for 39.78 (and back up 39.72 TX), which was their 1/2 duplex car tx frequency, and then they had a MASTR II station which was the 39.72 TX to the cars, and 39.58 tx too. Reason - full duplex on the car to base / base to car..they could hear one car while talking to another (on separate stations), redundant 39.58 (statewide in those days), and mostly because the Motorola received better, and the GE had better TX audio. I think the Moto was 100 watts and the GE was 250 running about 175. They were on the same building, both on DB201 antennae and at different heights and sides of a water tower.

 

The cars had Micor mobiles and could TX on 39.78 to talk to the base, 39.58, and 39.72...because they also scanned 39.78, along with 39.58, and 39,72 (priority). Interesting setup.

 

Oddest station I ever saw was a UHF MSF that was a T4 4R configuration, and was a 12 watt station. It was used for a control base, 4 different repeaters, could TX to them one at a time, but hear all 4 anytime. It had preselectors, and a duplexor like a repeater. The rx audio from the repeater you were txing to was simply muted at the console, and the position you were using, to prevent feedback. It was for a fire dispatch.

 

And lastly i knew of a VHF IMTS that ran 330 watts, had a receive antenna at 180 feet on a 1800ft hill, and the tx was at 100 feet on that tower....that thing would talk. Once it was down to about 80 watts and no one noticed, but at that point only 1 Moto service guy in our shop still had a mobile and the company it belonged to had 5 or 6 and didnt use it much.   

[n4gix]

I had my handyman drive me up to Milwaukee, WI today to pickup the "monster" repeater. Good grief that bloody thing is heavy. Between us though we managed to get it loaded onto his pickup truck and secured, then trundled back down to Hammond, IN.

 

It was a major PITA to get the bloody thing up the front steps and placed in it's temporary home in the front area of my living room. Just the perfect accessory for anyone's décor! Eventually I'll get the 2C ICOMs re-crystalled on my GMRS frequency, tune the receiver and transmitter, and find a more appropriate home for it...

 

...like at a tower site!

 

Oh yes, Terry had quite a few 50 amp GE power supplies so I snagged another one for $20 while I was there. One can never have too many power supplies, especially those really well-built transformer GE units.

 

He also has a couple dozen Motorola Motrac mobile units he's giving away for the taking, but I have no use for them. I've got enough junk already!

 

http://puu.sh/rczsv.jpg

[rfmedic]

Bill if you need any help with the MASTR 2 or any questions let me know. I ran several of those exact stations both ham and commercial (@ the full 200watts) and they do work well. However they are aging so hopefully you don't have any major issues to sort out. Repair is usually a piece of cake as long as the exciter and receiver decks are in good shape. The PA's are the most common failure point. Station PA is approximately 250-500mw drive for 75-100out and the upper 2 standalone PA's are around 25-35watts in for 100watts out each.

[n4gix]

Thanks for the offer. I'll keep that in mind. It's been many long decades since I sold my GESS in South Texas (Kingsville/Corpus Christi) where I had several hundred MASTR II repeaters installed. Of course all of my service equipment and manual went along with the sale.

 

At least I do still remember most of what I'll need to know. Oddly enough, I've not even powered this up yet as I've really had no time. I'll get around to it over the winter though. I'm going to thoroughly test the receiver and exciter on the current frequencies before sending the 2C ICOMs off to International Crystal though.

 

If I need any replacement parts, I'll have to buzz up to where I bought this as Terry has a couple dozen trays and other parts taking up space...

[Logan5]

That thing will play double duty in the winter. If it get's cold inside just key it up a few times. LOL..

[n4gix]

At least I do still remember most of what I'll need to know. Oddly enough, I've not even powered this up yet as I've really had no time. I'll get around to it over the winter though. I'm going to thoroughly test the receiver and exciter on the current frequencies before sending the 2C ICOMs off to International Crystal though.

Three years later. Unfortunately, International Crystals went out of business just a few weeks after I bought this repeater, and they were the very last company to grow and frequency/temperature compensate ICOMs in the world as far as I can determine.

 

I did part out the twin PAs for $100 each, so at least I recovered my investment. I've got a couple of Ritron repeaters lying around, so I may use one of them instead of the GE exciter/receiver to drive the Station PA, and find a smaller cabinet for the final build out.