Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Possible Fried Transformer On EMUD T7
#1

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 Ancient, outdated lines that are patched on top of patches out here.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

No matter where you go, there you are.
#2

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!

--
Ron Ramirez
Ferdinand IN
#3

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.
#4

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
#5

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.

No matter where you go, there you are.
#6

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.

No matter where you go, there you are.




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
Philco P45-6365 Universal Transformer Instruction Manual
Can anyone guide me to where this may be found?GRG — 03:00 PM
54C Complete Teardown/Rebuild
I don't think that I have encountered a 12Z3 before, curious how it uses one of those but includes a #43, which is a 25 ...Arran — 02:17 PM
HiFi (Chifi) tube amp build - but my own design.
It's the other forum. I'm also in DIY, but mostly read there. Honestly, I kinda jumped into this without much thought to...TV MAN — 10:43 AM
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM

[-]
Who's Online
There are currently 1880 online users. [Complete List]
» 2 Member(s) | 1878 Guest(s)
AvatarAvatar

>