Thanks Vinny. I'll check the power supply and see if droop is occuring on
Tx. I need to take a close look at the schematic and check the low current
line. I think it is 8VDC. The seller was nice enough to tell me that he
removed the battery from the microphone so that damage wouldn't occur. He
probably figured that it would take me a few days before tested the radio.
Whenever I get ahold of an eBay item, the first thing I do is open up the
unit and make sure that somebody didn't try to align it. Next, I connect up
an RF generator and measure the sensitivity, after which I check the RF
output and modulation index of the transmitter on a service moniter. Looks
like I picked up another "tech special".
This unit isn't as bad as the Drake TR7 I picked up from a fellow in Ohio
last year. He conveniently didn't include a microphone or a power cord, but
he was nice enough to include a Cinch Jones connector for the 12V input.
I had a PS7 power supply on hand, and I noticed that power output was low on
10M. I found a cold solder joint on one of the exciter boards. In an attempt
to cover up the problem, he defeated the ALC circuit, so after I repaired
the unit and checked the power output it was putting out over 275 watts. I
readjusted the ALC and everything was fine.
When I contacted the seller and shared my findings with him, he said "Oh, I
was wondering why I had to crank up the mic gain with this one".

Pete

"Vinnie S." wrote in message
...
On Sat, 17 Feb 2007 01:59:59 -0600, "Pete KE9OA"
wrote:

Another eBay special that "worked perfectly". It doesn't matter if I put
in
an external audio source from an audio oscillator or a microphone. I've
tried three good microphones, and have the same problem. When I first key
the mic, Tx audio is fine, but it quickly, almost abruptly fades after
about
2 seconds. Has anybody seen this problem?

Pete



I had this problem on my 2510. Ended up finding out that my power supply
wasn't
cutting it. I went to a larger power supply. Since yours in internal, I am
not
sure that is the problem. But the damn symptom iwas the exact same.

Vinnie S.