[UK-CONTEST] A Question for all you 'MP experts out there...

[John Wayman]

Hello,
A while ago, my FT1000mpDC started playing up - a bit chirpy, and occasionally, 
on full power, it would do a firmware reset.
I did some digging about with the DVM and the 'scope, and discovered the DC 
power relay (operated by the front panel on/off switch) had gone high 
resistance. I replaced it, and all was well. Until, that is, a few weeks later, 
when it started chirping again, worse than ever. People started giving me 59C 
reports! No sign of the firmware reset, though, and the voltmeter on the front 
panel was not dipping by a couple of volts like it used to!
I have done some measurements again, and the volts at the PA feed seem to drop 
by just over a volt at full power. If I drop the power to 30 or 40W, the chirp 
(at least in the monitor on the transceiver) seems to go away. The chirp sounds 
much worse on the higher bands than it does on 160, 80 or 40.
It seems to me that something else has now gone wrong, not the original relay 
problem again, because there is very little drop across the relay contacts - a 
few hundred millivolts, maybe.
Do you have any idea what the problem may be? Have you come across this problem 
before? I am only a humble Mechanical Engineer, and I have just about reached 
the limit of my incompetence at fault-finding, so I need some ideas of where to 
look.

Thanks for reading. I look forward to hearing some ideas of how to fix it.


73,


John
G4DRS