AM Volume Low - Printable Version
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AM Volume Low - 1230AM - 02-07-2020
Greetings,
I'm new to radios (Pretty much still super green at this) and the forum, and I know just about enough to get myself in trouble. In looking for an answer here I find myself lost fairly quick. I have re-capped three sets and am so far batting .1000, until this one - but I'm getting there. Did I mention a radio schematic looks like a bunch of lines to me?
Anyway, my 47-1230 volume went down to almost nothing and then stopped when listening to AM a while back. The set has had nothing done to it and was working fine until then. Yes, I realize i was on borrowed time - but it was doing so well. So I re-capped it. Did the last one today. Discovered a weak 7AF7 tube as it was the only one that didn't look like it was lighting up, and replaced it. It helped.
Where I could never before pick up FM stations I get them now. The phono volume works great, always did, FM volume works good depending on the station, not as loud as the phono. On AM though, I now get super low volume where before it had great volume.
I checked/wiggled the antenna, connections check ok to me. Checked underneath before putting it all back and nothing looked loose, my soldering while not pretty, was solid.
I've yet to have the other tubes checked. That's my next plan unless you good folks can point me in another direction - in a way I can understand.. ha.
After that I'm kinda stumped. Although, there are a bunch of very thin - what may be caps - still in there. About 10 of them. They say 100mf. I've replaced about 15 already, didn't know they had that many and I've never seen any that small before. Those I will address if someone with a 1230 can confirm those are indeed caps as well. Resistors escape me at the moment....
Thank you all in advance.
RE: AM Volume Low - klondike98 - 02-07-2020
Welcome to the Phorum!
For those following along here's the schematic from our library.
I'm sure others will have some thoughts for you. Have you gone through the troubleshooting found in the link above?
RE: AM Volume Low - 1230AM - 02-07-2020
Thanks for the reply!
No I haven't performed any of those tests. I can do the first section with volt meter, but for the rest I do not have an r-f signal generator. Weak current at one of those points cause low volume? Here's where my naivety comes in - is there not a specific thing that can to lead to low volume on the AM side only, or is it a combination of many other things? I have zero experience in electronics other than replacing some caps and getting lucky.
Told you I know enough to get myself in trouble........ha