24-04-2012, 09:39 AM
(23-04-2012, 10:35 PM)Skywave Wrote: One day, this radio will be fixed - keep that in the back of your mind; it's just a question of when, not if.
I quite agree, Al, and the sooner the radio itself realises that the better!
I had a revelation just before nodding off last night: that I was trying to set the quiescent current while the set was playing so obviously it would be far higher than when off-load.
This morning I had a go at doing it properly.
With RV2 set to maximum resistance the current is at zero. Advancing this control smoothly increases it 'til it's getting towards 3mA at which point it suddenly jumps up to 30mA. I've closely examined that with both my eyes and an ohmmeter which seems to rule out it being damaged.
With it set as high a it will go, prior to the jump, it plays OK at low volume but as it's increased it starts to distort. It's difficult to describe sound in words but the best way I can describe it is like a cheap transistor radio sounds when turned full on, but this is nowhere near as loud. I'll get my 'scope across the speaker later and see what that looks like.
It is actually fine so I'm going to get on with cutting the wood for my new PSU while I can.
- Joe
