17-11-2012, 06:09 PM
Hi,
I'm trying to fix one of these. Not fun, I can tell you :o
It's very very deaf on FM. But, injecting a 10.7MHz connection at the output of the FM tuner shows that the IF sections are working fine - the IF amplifier seems to be very sensitive indeed.
So, problem is in the tuner. Osc is working, because I can tune to signals from my generator (can only pick up R2 very weakly here with a direct feed from the aerial amplifier).
When I cut the IF cable, the background hiss got quieter. This suggests that the second transistor in there is working. So, I'm guessing that the input amplifier is dead.
It took me a couple of hours to dismantle the damn thing. I'm not altogether sure I'll be able to put it all back together again - the mechanical construction is astonishing!
Anyway, I'm looking at the FM tuner PCB, but really need a schematic for this. I can't even identify the transistor types as they are funny little "bugs" - I'm really hoping they are OK, and that it's a problem with a passive component.
So, a copy of the schematic would be really useful. Just the FM tuner would help enormously. Can anyone help?
I know that RM.org have it, but I don't yet have enough "credit" there yet
Many thanks in advance,
Mark
I'm trying to fix one of these. Not fun, I can tell you :o
It's very very deaf on FM. But, injecting a 10.7MHz connection at the output of the FM tuner shows that the IF sections are working fine - the IF amplifier seems to be very sensitive indeed.
So, problem is in the tuner. Osc is working, because I can tune to signals from my generator (can only pick up R2 very weakly here with a direct feed from the aerial amplifier).
When I cut the IF cable, the background hiss got quieter. This suggests that the second transistor in there is working. So, I'm guessing that the input amplifier is dead.
It took me a couple of hours to dismantle the damn thing. I'm not altogether sure I'll be able to put it all back together again - the mechanical construction is astonishing!
Anyway, I'm looking at the FM tuner PCB, but really need a schematic for this. I can't even identify the transistor types as they are funny little "bugs" - I'm really hoping they are OK, and that it's a problem with a passive component.
So, a copy of the schematic would be really useful. Just the FM tuner would help enormously. Can anyone help?
I know that RM.org have it, but I don't yet have enough "credit" there yet
Many thanks in advance,
Mark
