The PHILCO Phorum
Possible Fried Transformer On EMUD T7 - Printable Version

+- The PHILCO Phorum (https://philcoradio.com/phorum)
+-- Forum: Various and Sundry Categories (https://philcoradio.com/phorum/forumdisplay.php?fid=37)
+--- Forum: Other Radios (Non-Philco) (https://philcoradio.com/phorum/forumdisplay.php?fid=12)
+--- Thread: Possible Fried Transformer On EMUD T7 (/showthread.php?tid=22836)


Possible Fried Transformer On EMUD T7 - Jayce - 09-18-2021

I was listening to my restored EMUD T7 for a short bit this evening and after about a half hour I noticed it was smelling hot around the transformer in the back as I was tuning in a station and immediately shut it down. Pulled the back and the transformer was so hot I could barely touch it and also checked our power coming in and at that moment it was reading 125 volts at the outlet! Icon_eek  That might not have been the peak as while I was watching it was SLOWLY setting back down and finally settled at 122 volts before I disconnected the meter. It's a 117 volt rated transformer, so I am hoping I caught it in time before one of AEP's famous power spikes through here killed it. I've had similar crap happen even out in the buildings, which are a separate line from the house and it drives me nuts! Ancient, outdated lines that are patched on top of patches out here. Icon_evil

RE: Possible Fried Transformer On EMUD T7 - Ron Ramirez - 09-18-2021

The voltage at my house regularly runs around 125 volts, with occasional peaks at 126.

That having been said, if your Emud's transformer became that hot, it must have an issue such as shorted turns in a winding.

I remember about six years ago, I had finished recapping a radio and was trying it out. I let it play on my workbench while I did something else in the basement. After awhile, I happened to glance over at the radio and it was smoking like crazy. Icon_eek The power transformer had died the death. And, wow, was it ever HOT...but, mind you, it was still playing!

RE: Possible Fried Transformer On EMUD T7 - BrendaAnnD - 09-19-2021

I think I still have a T7 carcass sitting over on my next door porch. It has a good transformer, I accidentally destroyed one of the IF cans and couldn't get my hands on another without buying another entire radio, so I've been parting it out and sending parts to folks that need them.

RE: Possible Fried Transformer On EMUD T7 - Arran - 09-19-2021

If it became like that suddenly I suspect a leaky bypass cap somewhere in the set. Most of those West German sets have taps on the primary to set the line voltage, but I don't think a line surge was the culprit, a few volts would not cause that in such a short time, I suspect some part going bad on the secondary side.
Regards
Arran

RE: Possible Fried Transformer On EMUD T7 - Jayce - 09-19-2021

Thanks, folks. I'll keep that parts set in mind if I need a transformer after all. I have to admit the transformer on this radio was always 'buzzy', so might have been at the end of its life to begin with. You can't set the power on this unit, it is preset at 117 volts and that is it. My other two German radios can be set for different voltages by moving the fuse around. For now, it will be getting a check to to confirm things and we will see what happens after that. It had the filter caps and such changed, but anything could happen and I've had brand new capacitors suddenly short out. It played fine earlier in the day with no issues and just like Ron said, it was still playing fine even with the smell. Saw no smoke, but didn't like that smell.

RE: Possible Fried Transformer On EMUD T7 - Jayce - 09-20-2021

I did the transformer test my late friend showed and the transformer is definitely bad. It heated up fairly quick, though not so bad that I couldn't touch it. So, on the back burner the T7 goes until I get some other things taken care of. I pulled out my Olympic Goldy 250, which is the beater of my small German radio collection. First one I bought for $25, flaking finish, original tubes that all test good, very basic restoration after seeing it worked well and it still works great. Oddly, the best performing of all my German radios is the beater! I keep it hooked to my little power reduction box as it is supposedly rated for 110 volts, but the powere transformer in this radio is larger than the EMUDs by comparison and uses diodes for the rectifier or does now at least as there was never a rectifier tube.