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

Pushbutton tuning problem
#1

I have restored a Philco model 41-296. The circuitry in this radio is very similar to several Philcos made in 1940 and 1941. It has seven tuned circuit pushbuttons.

The radio works perfectly in all respects but one. Although the three lowest frequency pushbuttons are clearly labeled as tunable down to 540 kHz, I can't get any of them to go lower than about 640 kHz. They all exhibit this same problem.

The ceramic trimmer capacitors associated with these buttons are antenna trimmers only and have very little effect on the tuned frequency. They have a great effect on how well a station comes in after tuning it in.

It appears that, in pushbutton mode only, the local oscillator just won't tune low enough. Any suggestions are most welcome.
#2

I don't have a schematic of the 41-296 but if it is similar to other Philcos of that vintage the fixed capacitor that is usually connected on the coil assembly in parallel with the coils is bad or has changed value. Most are 360 uuf. Replace it with a silver mica cap.

Kind regards,
Terry
http://home.comcast.net/~suptjud/
"Life is simpler when you plow around the stump."




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
New Philco Repair Bench
I am sure this is the archive, and not the Chuck's site.morzh — 09:50 PM
Made mistake & did not label connection
It's not like we are good friends with that wire and can tell it from other ptetty identical looking wires. Why'n't you...morzh — 09:49 PM
Made mistake & did not label connection
I'm not sure why that wire wasn't covered in the video. I'm pretty sure the 6A8 won't work until that pin is grounded. Y...RodB — 09:47 PM
Made mistake & did not label connection
You'll have to forgive me, I am not sure what you mean.  Can you explain what you are really saying.  If anyone does not...georgetownjohn — 08:05 PM
Made mistake & did not label connection
Those are details better left to the ones who know. Maybe you disconnected the wrong end of the wire.RodB — 06:22 PM
Made mistake & did not label connection
Maybe this is starting to make some sense in my hard head.  Is this why the wire in question was not in the great Ron Ra...georgetownjohn — 04:34 PM
Made mistake & did not label connection
I was correct with the 6A8 pin connection's, 7 and 8 are connected to ground as well as the tube shield (the broken line...RodB — 02:41 PM
Made mistake & did not label connection
What does the dotted line representing that surrounds the tube in the schematic?georgetownjohn — 02:17 PM
Made mistake & did not label connection
Hello John, I have been there either label got lost or was not labeled ! Sincerely Richardradiorich — 02:15 PM
Made mistake & did not label connection
Sorry, it is a Philco 37-640.  Does that help?--Johngeorgetownjohn — 02:14 PM

[-]
Who's Online
There are currently no members online.

>