Posts: 933
Threads: 140
Joined: Mar 2015
City: Lansdale
State, Province, Country: PA
Not sure where this should go.. Please move if its not in the right place
Question about a 50L6 tube.. I have 5 tubes that all check bad for shorts.. Is this normal ? Does this tube have high leakage? I cannot seem to believe all the tubes are shorted.. Or is this a common problem...
Thanks
Skip..
Posts: 16,272
Threads: 566
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
I forgot but in one of Kirk's radios where I had a 42 tube in the output I had the 42 that had a filament short (and was working). I bought another one and it was shorted too. And then another (the short disappeared after a while....????) Eventually I got one that was not shorted.
I do not think it could be normal for a tube to show a short. Even if it works (which is quite possible depending on the arrangement).
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 1,195
Threads: 83
Joined: Jan 2014
City: Annapolis, IL
State, Province, Country: USA
Maybe your tube tester? What tester(s) do you have? My Hickok did something weird like that on a 6SN7GT recently, even with the tube out of the socket... haven't gotten into it yet..
If I could find the place called "Somewhere", I could find "Anything" 
Tim
Jesus cried out and said, "Whoever believes in me , believes not in me but in him who sent me" John 12:44
Posts: 16,272
Threads: 566
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
Possible....though a similar suggestion was expressed to me back then and no, it was not the tester.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 933
Threads: 140
Joined: Mar 2015
City: Lansdale
State, Province, Country: PA
Ok I used a Hickok 600A tester and a Heathkit IT-17.. All showed short on 5 tubes.. Doesn't seem right. But maybe all 5 are bad? I wouldn't think so But who knows..
Going to see if I have any 25L6 or similar to see what they read..
Skip..
Posts: 16,272
Threads: 566
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
I think all 5 are bad.
This said, you might be able to use some of them in some circuits. It depends on how they are powered.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 933
Threads: 140
Joined: Mar 2015
City: Lansdale
State, Province, Country: PA
Ok plugged one of the tubes into radio the Zenith 5D011. All is well plays good with load and clear volume... No excessive current draw 117 Volts at .25 amps...
Thanks
all for the help..
Skip...
Posts: 5,129
Threads: 271
Joined: Nov 2012
City: Wilsonville
State, Province, Country: OR
I'm curious. If there is a short in the tube, does that mean that there is an unwanted connection between elements inside the tube? For example, between a grid and the plate. If so, shouldn't you be able to detect a short by putting your ohm meter across the various pin combinations? Or is there something else that can cause tube shorts?
Posts: 933
Threads: 140
Joined: Mar 2015
City: Lansdale
State, Province, Country: PA
I tried that. The tube I am using I checked for shorts pin to pin Tube cold. No shorts.. But when put in Tester showed short I think between Cathode and Filament according to the chart with my Hickok 600A..
Tube works in radio No problems..
Skip...
Posts: 16,272
Threads: 566
Joined: Oct 2011
City: Jackson
State, Province, Country: NJ
The short is mostly between the filament and the cathode, and this could be benign in some arrangements. In some others you might have hum. If it works, you are fine.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Posts: 2,031
Threads: 367
Joined: Jun 2010
City: Dover, OH
It can be amazing how you sometimes find faulty tubes in groups. Usually that doesn't happen, so it can throw one off when it occurs and it can be easy to blame the tube checker. One reason why my friend always said to keep a couple testers around. I have had a similar issue with type 47 tubes lately. I've managed to get three radios with push-pull 47s now and in all three cases one 47 in each radio was burnt out or would burn out as I was testing it. Tapping the tubes lightly would cause an arc inside them, but nothing else. I actually watched one burn the filament out on my tester when I tested the tubes in my Philco 90X.
No matter where you go, there you are.
Posts: 670
Threads: 11
Joined: Sep 2014
City: Bellmawr, NJ
THAT is what ,,I was show,,was to flick your finger against the tube ,,in tester,,while pushing the test button,,for any kind of short,,be-side the short test,,,CHEERS
Posts: 1,238
Threads: 30
Joined: Jan 2014
City: Wellborn Florida
50l6, 50C5, 35W4, 35Z5, If working on a All American set (AC DC) that has a bad tube good chance one of the following. David
Posts: 4,410
Threads: 416
Joined: Jun 2011
City: Boston
State, Province, Country: Massachusetts
Outputs and rectifiers often are candidates to go, if they were pulls maybe they are all bad, really.
Paul
Tubetalk1
Posts: 462
Threads: 40
Joined: Jun 2010
City: Lehighton
State, Province, Country: PA
I have 7 50L6GT here and none test as a short.
Users browsing this thread: 3 Guest(s)
|
|
Recent Posts
|
|
RCA T62 is playing.....
|
| Beautiful set.morzh — 09:07 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Well....here it is.
The green stuff. Unfortunately, probably penetrates deep.
I opened the top layer and saw that:
...morzh — 08:58 PM |
|
Philco 91 Restore Code ??
|
| :clap: :clap: :clap: :clap:
Really nice workmanship!!! Top of the chassis looks great.
Sorry about the long winded e...MrFixr55 — 08:09 PM |
|
Philco 40-120C Restoration
|
| Thank you for your reply. I will check voltages on the other tubes, look at resistor 23 and cap 25, etc. If all else fai...bluecap — 07:58 PM |
|
RCA T62 is playing.....
|
| Nice looking set great save. DavidDavid — 07:48 PM |
|
Philco 89 indicator light.
|
| Hello Jim, I have done several 89s. The trick is to move the drum in or out on it's shaft. You will need to loosen a set...dconant — 07:36 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| MrFixr
Yes, it is my plan to go with 45rpm spider if I go that far.
No, the pole was not left-handed as I unscrewed ...morzh — 07:14 PM |
|
Philco 40-120C Restoration
|
| Change the tube. Check the tube's bias network.
Are any other tubes experience the drop or just this?`
Is resistor 23 OK...morzh — 07:09 PM |
|
Philco 89 indicator light.
|
| I forgot how the pointer is formed: could you show the way it is formed and how you tried to change it?morzh — 07:01 PM |
|
An attempt to remove the Field Coil from a G speaker
|
| Was that pole piece left handed ?
Since the metal "spider" is toast, wonder if you can either get the "4...MrFixr55 — 06:54 PM |
|
Who's Online
|
There are currently 6925 online users. [Complete List]
» 3 Member(s) | 6922 Guest(s)
|
|
|
|
 
|
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
