Batboard

Have gotten a MSR2000 repeater that will not transmit at this point, beleive that it is the exciter / control board that is the problem. Anywho, have come up with an idea on this, any body have any comments or see something I might have forgotten, post it!

As far as can be found out right now, the power supply / transformer and the power amplifier are still functioning. The plan is to remove the control boards, and put in it's place a shelf. Then put 2 Maxtracs and a RICK (or similar setup) on the shelf and wire into the power supply. Would use the Maxtrac (turned down of course) as the exciter to feed the PA. The PA's in the other MSR2000's (that came out of the same batch that we have got) have been pushing 175-200 watts easy. So in effect we would have a 175 watt repeater. Any ideas / thoughts / concerns / comments / rude remarks / practical jokes? I'm interested to find out if anyone has tried this before or not... Thanks!

I had an MSR 2000 one time that would not transmit. No matter what jumpers I tried, it seemed that the PA or exciter was bad. I found that there was one card missing. Once I plug it in everything came to life. There are three horizontal card slots above the normal vertical card cage. It plugged into the horizontal slot. Just off the top of my head I am trying to remember, I think it was an F1 Control Module, but not sure.

Big BOB

Big Bob, you are right if any cards are missing the switchec channel element ground and switched A+ is not there. In a Tone Remote system there are the Gaurd Tone decoder and F1/F2 module. Also in the bottem section there needs to be the Station Control card. 3 cards total.
These cards can be "jumpered out" but that is a involved process if you are not familare with the station's signal paths. It is much the same as the MICOR base/rptrs.

Sounds possible, however I wish to point out, from real-life experience, that MaxTracs and Radiuses get HOT when transmitting, even if cranked way down in power, and the microprocessor inside will shut down the transmitter (by slowly lowering the output power to zero) after the radio has been transmitting continuously for anywhere from 20 minutes to 1 hour. Even with more than adequate cooling air on the heatsink, something else could be getting hot inside, and all the smarts in the radio will just "assume" that the PA is getting hot as well, and start shutting things down. For a repeater that could see 100% duty cycle for half an hour or more, these radios just don't quite make the grade. They do work well as long as they don't think they're getting hot.

There was a thread here on the BBS about exactly this subject. However, if you're using the mobile radios in a base station configuration, where the duty cycle is low, then they really do work great.

Bob M.

Ok, have some ideas now... Had already tried switching out the vertical cards in the card cage with another working repeater (from the same batch this one came from) and no luck, will try the horizontal cards as well... and also thanks for the information on the maxtracs getting too warm and shutting down... better to find out here then after we have the system setup and running....