08-09-2015, 08:12 PM
Well... I've learned a lot reading this forum, and acquired a replacement speaker from one member, so I feel compelled to close out this thread with an accounting of "how it turned out". Perhaps others can learn from my experience. It wasn't a bad oscillator transformer and fortunately I figured that out before I removed it from the circuit.
While ohm'ing it out in-circuit, looking for anything other than a fractional ohm between terminals, I noticed that cap #31 was connected to the wrong terminal on the terminal block mounted to the chassis side wall. One pin off, resulting in connection to chassis ground instead of a leg of the 1st I. F. transformer.
Fixed that, and voila, manual dial tuning works.
Now, I replaced that cap back when I recapped the unit. So -- although I'm not the first person to be doing repairs in this unit and it didn't work when I got it -- I have to conclude that I misplaced that cap when I replaced it. A real head-shaker, since I triple checked every cap I swapped out.
I used to tell the scouts in my BSA troop that every mistake is a learning opportunity, so here I'm concluding that comparing before and after photos after *every* component replacement is the rule from now on.
I'm refinishing the cabinet next and have a question about speaker grill cloth, so I'll post that on the other forum.
While ohm'ing it out in-circuit, looking for anything other than a fractional ohm between terminals, I noticed that cap #31 was connected to the wrong terminal on the terminal block mounted to the chassis side wall. One pin off, resulting in connection to chassis ground instead of a leg of the 1st I. F. transformer.
Fixed that, and voila, manual dial tuning works.
Now, I replaced that cap back when I recapped the unit. So -- although I'm not the first person to be doing repairs in this unit and it didn't work when I got it -- I have to conclude that I misplaced that cap when I replaced it. A real head-shaker, since I triple checked every cap I swapped out.
I used to tell the scouts in my BSA troop that every mistake is a learning opportunity, so here I'm concluding that comparing before and after photos after *every* component replacement is the rule from now on.
I'm refinishing the cabinet next and have a question about speaker grill cloth, so I'll post that on the other forum.