New here at Chuck Schwark's recommendation. I have a power transformer on my Philco 38-12T that is fried. Has anyone found a suitable replacement and if so from where and what model? I've been striking out in my search.
Thanks.
Ron
The transformers will do for 38-15, 39-7, 39-6.
38-12 in a table mod uses small speaker and a small transformer, but the one from the chairside version will work fine except it will have to be maneuvered to go the small enclosure (possible, did it on mine).
I do not have voice coil impedance for these, but if you unsolder the secondary of the xfmr and measure (accounting for your meter leads' resistance) the Voice coil, then you could match it to 41 tube output and see whether the 125 SE has a tap that is close enough.
Hi Ron, Welcome to the Phorum!!
Put a Wanted Ad in the wanted ad section...someone might have one and see your request there.
You don't list your location but if anywhere near Kutztown PA there is a big swap meet coming up (see the Swap meet section).
Are you the same person who started the thread as the unregistered guest? If not, I'll split the thread to avoid confusion.
(04-16-2015, 04:27 PM)morzh Wrote: [ -> ]The transformers will do for 38-15, 39-7, 39-6.
38-12 in a table mod uses small speaker and a small transformer, but the one from the chairside version will work fine except it will have to be maneuvered to go the small enclosure (possible, did it on mine).
I do not have voice coil impedance for these, but if you unsolder the secondary of the xfmr and measure (accounting for your meter leads' resistance) the Voice coil, then you could match it to 41 tube output and see whether the 125 SE has a tap that is close enough.
Thanks much. I'm pretty new to this game and learning a ton. I've been restoring old box fans and moving on to something more challenging ;) Any preferred sources such as Radio Daze where I should look? Again thanks.
Ron
(04-16-2015, 06:09 PM)klondike98 Wrote: [ -> ]Hi Ron, Welcome to the Phorum!!
Put a Wanted Ad in the wanted ad section...someone might have one and see your request there.
You don't list your location but if anywhere near Kutztown PA there is a big swap meet coming up (see the Swap meet section).
Are you the same person who started the thread as the unregistered guest? If not, I'll split the thread to avoid confusion.
Thanks. It wasn't me who started. I didn't want to clutter board since it was same topic. I'm in Knoxville, TN... Wish I was up in PA. ;) Appreciate the help.
Ron (ronlubke)
Drive over to Nashville Saturday morning. There is a swap meet going on there. Details:
http://musiccityvintageradio.org/
It starts early - around 7 am CDT - and wraps up by 10:30 am.
Of course, no guarantees that there will be a 38-12, 38-15, 39-6 or 39-7 there...but you never know...
Just to clarify things, the power transformer is DOA in your 38-12, not the output transformer? Is the field coil on the speaker fine as well? Yes, I think that hitting the upcoming swap meet might be the best solution for a replacement, given that a 38-12 was a popular set, and that there were later versions of it and the 38-14 that had Bakelite cabinets, you may be able to find a parts chassis with an original power transformer. If not there are a whole host of different makes and models that used power transformers of a similar size and style that used either a #41 and a #84 or a 6K6GT and a 6X5GT or a 6X4 and a 6AQ5 (no not every 6X5 equipped set was badly designed like the brand Z sets) , but a some even had a proper 5 volt rectifier winding.
Regards
Arran
I misread it as outut, but same thing applies - the same listed models have very similar or the same power xfmr.
The B+ voltage will be lower with a 39-6 or 39-7 power transformer, but that might be a good thing.
Thanks all. I really appreciate it. I did not make it to Nashville -- my kids wanted attention from me so I spent the day playing baseball and digging in the yard with them ;)... Really, couldn't have asked for a better day.
I found a 38-12 at a good price. I picked it up and see how it comes together. The chassis and components look in much better shape than what I have but the cabinet is worse for the wear. I may Frankenstein the two together.
Arran -- thanks. Right now what I get is smoke and a burning smell coming from the transformer when the rectifier tube is in.
Well.....it is likely your rectifier tube/bad caps and not your transformer, though you could've killed it by now.......
(04-20-2015, 02:53 PM)morzh Wrote: [ -> ]Well.....it is likely your rectifier tube/bad caps and not your transformer, though you could've killed it by now.......
morzh:
Love the signature ;)
A couple of things:
1. I did replace the rectifier tube. Still had the same issue
2. I recapped the radio prior to even turning on
3. I used variac and brought power up slowly
4. The "under carriage" was a mess when I got it especially when looking at caps.
5. A lot of the caps including electrolytics used were not close to the same size that the parts list had. I rectified that.
6. I'm going to remeasure the readings coming off the power transformer later this week to compare again to schematics
7. Thank you for taking time to help me learn and offer suggestions.
Ron
Ron
Simple question: if you power WITHOUT rect tube, does it still smoke?
If yes,
If you fully disconnect all your xfmr outputs from wherever they go (filaments etc), and then power, does it still smoke?