Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

AM Volume Low
#1

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.
#2

Welcome to the Phorum!
Icon_wave

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?
#3

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




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 42-1008 conversion kit
I read about a kit to convert the variable speed changer in the Philco 42-1008 into a single speed unit.  That would rem...alangard — 09:30 PM
HiFi (Chifi) tube amp build - but my own design.
Tim Well...a chassis is metal. Magnetic or not, it does not matter. A transformer has some hum to it. It is natural....morzh — 08:40 PM
Hickok AC51 tube tester
I thought the 83 tube was bad because it looked white but it tests strong. Blue gassy though. I checked the fuse, it was...martinj — 08:37 PM
Shadow Meter Bulb
Ross I am not sure what current limiting effect the incandescent provides. They are two different parts of the sch...morzh — 08:31 PM
12' Philco
Bob Thanks for that photo. I have been looking for it, and I cannot find anythinmg on the web. I forgot it was here...morzh — 08:29 PM
Shadow Meter Bulb
I think after all has been said, I will use the same bulb that is specified for the dial pilot light which is a #55. I ...georgetownjohn — 07:31 PM
12' Philco
There was also this Philco! klondike98 — 07:25 PM
HiFi (Chifi) tube amp build - but my own design.
I expected a challenge and this is just part of it. But, it's also supposed to be fun, entertaining, informative and enj...TV MAN — 07:12 PM
Shadow Meter Bulb
Butting in here with a question. Since the shadow meter is connected directly to the 1st and 2nd I.F.'s wouldn't the met...RossH — 06:43 PM
HiFi (Chifi) tube amp build - but my own design.
Mike, Tim; you are about to enter the twilight zone. Doo doo doo doo, doo doo doo doo This is something alright. I'm go...RodB — 06:26 PM

[-]
Who's Online
There are currently 7425 online users. [Complete List]
» 2 Member(s) | 7423 Guest(s)
AvatarAvatar

>