02-21-2015, 01:37 AM
Hi Guys,
It's time to pick everyone's brain again.
I have this Zenith H725 with a problem. On AM, with full volume, barely able to hear any stations. FM nothing. I have replaced all caps (not micas). All resistors have been tested and replaced if out of specs. All tubes tested. I've also swapped them with known good ones. All connections double checked for accurate component replacement. On AM, I'm not concerned about FM for the moment, with my signal tracer I go as far as pin 6 on the 12BA6-the 2nd IF where it connects to the 3rd IF can. The signal stops there. I replaced the 3rd IF can-no change. I did find out that if I jump from where the signal stopped (pin 6 of 12BA6, 2nd IF) to pin 6 of the 12AU6 Limiter, I get great volume and all AM stations up and down the dial.
Any ideas where to look?
Thanks,
It's time to pick everyone's brain again.
I have this Zenith H725 with a problem. On AM, with full volume, barely able to hear any stations. FM nothing. I have replaced all caps (not micas). All resistors have been tested and replaced if out of specs. All tubes tested. I've also swapped them with known good ones. All connections double checked for accurate component replacement. On AM, I'm not concerned about FM for the moment, with my signal tracer I go as far as pin 6 on the 12BA6-the 2nd IF where it connects to the 3rd IF can. The signal stops there. I replaced the 3rd IF can-no change. I did find out that if I jump from where the signal stopped (pin 6 of 12BA6, 2nd IF) to pin 6 of the 12AU6 Limiter, I get great volume and all AM stations up and down the dial.
Any ideas where to look?
Thanks,
Eric
Lake in the Hills, IL
Member: Philco Phorum, ARF, ARCI & Radiomuseum.org
