Posts: 15
Threads: 8
Joined: Sep 2019
City: Eau Claire
State, Province, Country: Wisconsin
I am in need of two new type 41 tubes (from a 41-290 Philco). Is this the replacement?
https://www.tubesandmore.com/products/41...e-st-glass
Thanks for the help!
Posts: 7,273
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
Yup...
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 1,824
Threads: 114
Joined: Jul 2014
City: Sneedville, TN
The ST refers to the glass envelope. It means a tubular envelope. It will be a constant diameter all the way from the base up, rather than bulging like a regular 41G. It is a direct replacement despite looking different because of the envelope.
Posts: 112
Threads: 36
Joined: May 2015
City: Brandon, SD
I thought ST stood for “shouldered type”, and the GT type was the consistent diameter type? ST and G are the same thing and GT was the later, non-shouldered glass versions?
Posts: 124
Threads: 18
Joined: Jan 2018
City: Kingsville Ohio
Best place I've found to get tubes: findatube.com Bob Dobush has tons of tubes and I checked; 41 new $6.50 used $3.00. Hope this helps.
Dick
Posts: 1,824
Threads: 114
Joined: Jul 2014
City: Sneedville, TN
ST is not actually a standard abbreviation. I believe I saw it on only one tube I ordered which was Russian made. G is what you call "shoulder type, GT is the later, smaller, straight side version, and later many GT types are marked GT/G to save confusion, clearly showing it replaces either. Except for looks they are the same , BUT, if there is NO SUFFIX, and the tube has a metal outside, it can be a problem in Philco radios. These metal tubes use the case as an RF shield, and it connects to a pin that is connected to the ground plane of the radio. Philco radios use the G or GT types which do not use this pin, and so use the socket solder lug as a tie point, which can be live, so you can't use a metal tube in Philcos safely, metal does not substitute for a G or GT type. This is why many RCA radios don't use tube shields for their RF, oscillator, and IF tubes, the metal tube IS the shield, but Philcos and other radios use those shields and G or GT tubes.
Posts: 301
Threads: 31
Joined: Dec 2019
City: Elkhart
State, Province, Country: Indiana
Quote:Except for looks they are the same , BUT, if there is NO SUFFIX, and the tube has a metal outside, it can be a problem in Philco radios. These metal tubes use the case as an RF shield, and it connects to a pin that is connected to the ground plane of the radio. Philco radios use the G or GT types which do not use this pin, and so use the socket solder lug as a tie point, which can be live, so you can't use a metal tube in Philcos safely, metal does not substitute for a G or GT type. This is why many RCA radios don't use tube shields for their RF, oscillator, and IF tubes, the metal tube IS the shield, but Philcos and other radios use those shields and G or GT tubes.
Hi Mike, does this also apply to Zenith radios as well?
I'm wondering because I have a 1942 Zenith 10S690 Radio that all of the tubes in the radio are of the G type variety of tubes and all of the critical tubes in the set had shields around them, there was one tube in my Zenith that was replaced at one point in time that was replaced with a metal cased tube and the original tube shield was tossed when they installed that metal cased tube into the radio (the radio other than the 6A8 tube and the 5Y4G tube has all of its original Zenith tubes in it yet).
Posts: 1,824
Threads: 114
Joined: Jul 2014
City: Sneedville, TN
Pull out the chassis and the metal tube, with the radio unplugged, of course. Then ring out between pin 1 and ground, as well as between pin 1 and the other 7 pins. Pin 1 should either not be connected to anything, or it should be connected to ground. If it is connected any other way, the tube should be a G or GT type, not a metal tube.
(This post was last modified: 02-11-2020, 04:22 AM by mikethedruid.
Edit Reason: spelling
)
Users browsing this thread:
|
Recent Posts
|
Correct model 84 Ac plug an cord type
|
From what I read Philco went to using brown rubber power cords in 1936, so cloth was used in the 1935 and earlier models...Arran — 11:25 PM |
Correct model 84 Ac plug an cord type
|
Hi Bruce,
I have not worked on an 84, but in general, power cords for almost any radio prior to 1938 was cloth covered...MrFixr55 — 08:34 PM |
Restoring Philco 38-14
|
OK, well, so after staring at the sch again, I realized the problem had to be the #12/12A padder.
I put a scope on the o...morzh — 08:15 PM |
Correct model 84 Ac plug an cord type
|
Hello Bruce,
I mostly use brown far as my cloth powercords go !
Here is the plug that I have used bakelite Acorn style...radiorich — 08:05 PM |
Correct model 84 Ac plug an cord type
|
Looking for as correct as can find the right Ac plug an the correct colored cloth line. Ive seen many old photos but mos...Bruce — 04:13 PM |
Restoring Philco 38-14
|
Rod
Two Y-caps make sense if you use them from L/N to the chassis; this is only makes sense in the transformer radios...morzh — 10:11 AM |
Restoring Philco 38-14
|
Mike, I'm curious about a specific use of he Y cap. Lately I've seen a single cap across the power transformer primary. ...RodB — 09:01 AM |
Restoring Philco 38-14
|
hello morzh ,
That sounds like a plan !
Sincerely Richardradiorich — 07:45 AM |
Restoring Philco 38-14
|
Richard,
It helped some, but I still had the whining when engaging the rear power strip (I did not realize it was fro...morzh — 07:07 AM |
Restoring Philco 38-14
|
Hello morzh,
Yes , that dreaded hum in my room where i do alighment I have my cable modem and router plus desktop plus ...radiorich — 11:25 PM |
Who's Online
|
There are currently 3193 online users. [Complete List] » 2 Member(s) | 3191 Guest(s)
|
|
|
|