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5X4 tube socket replacement - Printable Version

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+--- Thread: 5X4 tube socket replacement (/showthread.php?tid=16464)


5X4 tube socket replacement - murf - 03-30-2017

Hello guy's,
Looking for a replacement tube socket for the 5x4 rectifier tube that is parked on top of the transformer on my Philco 38-116.
Looks like someone has replaced it before with a cheap generic socket.
It is mounted with a couple sheet metal screws located 1 5/16 center to center.
Looks like the 4 wires could use some spaghetti tubing once it is apart.
If I remove the top cover on the tranny, can I gain better access to these wires or are they buried in the coil?
Don't want to dig into it until I have a good socket.
Anyone on the forum have any advise on doing this repair?
Was going to sell this one as I have another already, but no interest on the forum, so, I will fiddle with it when I have spare time.
Thanks,
murf

RE: 5X4 tube socket replacement - Ron Ramirez - 03-30-2017

Murf

Sorry I have not had a chance to answer your email, so I will just answer it here.

The original tube socket was held in place by a cylindrical piece of metal with a flange on top to retain the tube socket. This has two slots in the top of it. Four tabs which protrude from the top transformer bell go through the two slots and were spread out at the factory to hold the cylindrical piece in place, which in turn holds the rectifier tube socket in place.

You can gain access to the wires as soon as you remove the cylindrical piece and the tube socket. WARNING - the wires are cloth-covered, but the insulation will disintegrate once you start messing with them. I do think that removing the top bell (cover) is a good thing to do, once you have removed the tube socket. Then you can resleeve the wires with heat shrink tubing before reattaching a tube socket.

The tube socket that will fit the best is one from a 1937-38 Philco power transformer, as they were made for the purpose (proper fit and all). Any octal socket from any 1937-38 Philco power transformer will work; the sockets themselves (as well as their cylindrical keeper sleeves) are all the same size, I believe.

Advice? Find a donor chassis to obtain the proper tube socket (and cylindrical sleeve if yours is missing). Carefully remove the old tube socket; don't move those wires any more than you have to while unsoldering the wires from the old tube socket. Remove the top bell (cover). Resleeve the wires as their insulation will crumble once you start messing with them. Good luck...you'll need it. Yes, you can do it, but you will have to be careful and patient.

RE: 5X4 tube socket replacement - murf - 03-30-2017

Thanks for the reply Ron,
Mine still has the original cap and sleeve, but they drilled a couple holes in it and screwed the generic socket to it.
I will see if I can find the correct socket.
Apprarrently the original was just held in by the cap?
Thanks Ron,
murf

RE: 5X4 tube socket replacement - Ron Ramirez - 03-30-2017

(03-30-2017, 08:02 PM)murf Wrote:  Apprarrently the original was just held in by the cap?

Correct. Well, that plus the tabs I mentioned previously.

RE: 5X4 tube socket replacement - murf - 03-31-2017

Interesting question.
I found an octal socket and swapped it out after using a shrink tube on the old wires.
Re-wired same as the socket I removed that was put in by someone previously.
Hooked it up to my variac and brought it up slowly without the tube.
Then installed the tube and again brought it up slowly.
Tube filaments not lighting up.
Tried another good tube and the same.
Used my volt meter and checked voltages on the pins.
Looking at the top of the socket, have 2 wires on pins 1 and 7. pin 1 checks .236v AC
 and pin 7 checks 4.93v AC
High voltage wires are connected to pins 3 and 5. Both check 367 volts AC.
Are these the correct pins for this tube?
My schematics are not readable as far as pin voltages.
All I can make out is there are 2 marked plate and 2 marked heater.
Did I duplicate a mistake made by the previous repairman?
I can always drag out my other 116 and measure the voltages on the pins on that one and see if maybe they are not connected to the proper pins.
Lets see if we can light her up tonight.
murf

RE: 5X4 tube socket replacement - Ron Ramirez - 03-31-2017

You miswired the socket. The plates are pins 3 and 5, yes, but...the filament connects to pins 7 and 8.

http://nj7p.org/Tubes/SQL/Tube_query.php?Type=5X4G

RE: 5X4 tube socket replacement - murf - 03-31-2017

Will fix that tonight.
Thanks again Ron.
Murf

RE: 5X4 tube socket replacement - murf - 03-31-2017

Good news Ron and crew,
Wired the rectifier socket per master Ron and the radio came to life.
It is receiving well to boot.
Apparently the previous owner attempted to replace the socket and wired it wrong.
It was wired to pins 1,7,3,and 5.
Ron told me it should be 7,8,3,and 5.
I wired it the same as the previous owner did and of course that was wrong.
Also discovered the center lugs were broken off of both 6L6 tubes and they were installed wrong as the timing was off.
This blew a resistor.
Replaced that and we now have a restorable chassis.
Many thanks to Ron and the forum.
Now for the re-cap.
murf

RE: 5X4 tube socket replacement - Radioroslyn - 03-31-2017

If you to save your 6L6's :
https://reverb.com/item/2465597-6-pieces-vacuum-tube-octal-socket-saver-missing-broken-guide-key-fix-repair?gclid=COmuia2pgtMCFUVYDQod5AUG8g&pla=1
May be some cheaper ones around.

RE: 5X4 tube socket replacement - murf - 04-01-2017

Great idea.