Batboard

I have 3 GR1225 (P1225 radios) repeaters that have the same symptoms.
They have transmitt power for less than a second and then no transmitt power. The red light stays on and the power amplifiers do not have an overcurrent feedback shutting the controlled voltage down. It seems like a logic problem. There is a DAC converter that affects the PA bias and is shutting it down. I have a common problem somewhere. Voltage or corrupted proms?? Motorola has no PSD/SRN

There was a known problem with some of the GR500/GR1225 repeater power supplies shutting down under heavy curant loads, and even some would kick out at only two amps. They had a faulty/wrong value resistor in them.
Substitute a known good power supply, disconnecting the original one in the GRxxx.
Also check the transciever on the bench.
There is also an over voltage detection on the controlled A+ going to the PA. Make sure that you do NOT have high VSWR or that the soft pot(s) for the transmit power are not set too high, this causes shut down, and sometimes after 5 seconds keyed. Some PA boards may have poor or overheated solder on the A+ current sense circuit. All due to running them too high power and getting too hot.

<font size=-1>[ This Message was edited by: Will on 2001-11-10 04:30 ]</font>