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

Philco 90 question
#1

I have a 90 chassis, the one with a single '47 output tube. I've been recapping this thing, and it's coming along pretty well, but there's one odd thing that I've noticed.

I keep having trouble with the '24 IF amp. Every once in a while it dies until I tap on it (the original one had an intermittent short in it, if it died and I tapped on it, it would come back, but I could see it arcing inside). What is interesting is, when the tube dies, or when I remove it completely, I can still hear the tuned in station in the speaker, although the volume control has no effect. I've tracked the signal paths and I find that all the bypass caps in the signal paths have already been replaced.

Both of the shields are missing. I have fashioned a shield around the IF amp, which seems to be very touchy, and breaks into oscillation at the drop of a hat, and this cleared up the oscillations.

Is it possible that I am going to have to locate the original shields in order to keep this 'ghost' signal out? I would not worry too much about it, but I'm thinking it may be out of phase and therefor cancelling some of the signal.

TIA
#2

Someone here once mentioned someone else who makes shields for Philcos. Pretty close looking to those original ones.


Are you saying that the shield makes the IF work normally and it no longer dies? Or you just mixed the two together?
#3

The tube still dies on occasion, it just no longer throws the radio into oscillation. Time to order some more '24's.

Don't suppose you remember who it was that makes those shields?
#4

The gentleman's name is Chuck Paci; he may be reached at cpaci1 at verizon dot net. He does not make the round shields, but he does make the large shields that fit over multiple tubes in Philco 70, 90, 112 and a few others.

--
Ron Ramirez
Ferdinand IN
#5

Thanks, Ron. I'll contact him. Those are the ones I'm looking for.




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.

>