DD1US , I think I agree with you, because in my case, the problem had appeared when I changed the way the 28 V was apply to the amp. At the beggining I switched the power supply, all was fine. In a second time, I switch the 28 V of the amp via a manual switch, with power supply ON, and the fault appears...
So may-be we need to slowly supply the amp...
73,
Roland F8CHK
Faulty resistors: in my case it was a change in value, they got a high value, so no bias at all. Why that change? this is the question ! and it appears to arrive frequently...
Hope it will be good for a while now!
73,
Roland F8CHK.
Hi Oscar,
Tnx for the reply, this is exactly what I wanted to know! yes my resistors were faulty, and I replace them by 150 Ohms, amp is working again, may be with a slight different bias current.
I think I will go for the 2 x 22 ohms in parallel next time I will open the case!
I am also thinking of using the 28 V bias as a PTT, instead of permanently consumming some 2 amps even in receiving periods, looks like it is possible, what do you think?
73,
Roland F8CHK
Hi all,
Using a Nokia with 2 BLD6G22L 150N/2, after a while I had the same problem as some OM on the list, Bias current disapears...
I am a bit confused with the solution to this problem, some post (#353) refers to a 11 ohms value, and other post (363) to 150 ohms value, or may-be they are not speaking of the same resistors?
Can you help me to be sure?
Tnx and see you on QO-100!
73,
Roland F8CHK
