Hello Guys;

Last week I was lucky enough to drive by a garage sale in the area and when I left, I was the proud owner of two German radios. (Both at a very good price)

A Telefunken Opus 7 Usa model and a Telefunken Gavotte 8 U (USA model also)

I've been searching and learning about them as much as I can and I underestand that both should be recaped etc.!

My knowledge in electronics is very limited, but I'm very, very handy and I am confident enough to know that I'll get them both going with a little help from you guys.:yes:

Could anybody point me in the right direction as far as trying to obtain schematics for them (there were none in the back) and maybe, just maybe if someone happens to have a parts list for me to order the right capacitors, diodes etc. for them??

Any help you could send my way would be extremenly appreciated.
Thank you guys:thmbsp:
Victor

Madwing posted this link recently, might find what you're looking for here:

http://www.radiomuseum.org/

Opus 7 is coverd in Sams Photofacts, folder 341-16. Gavotte 7 (no 8) is in 399-12. I see that both schematics are at radiomuseum.org - I'm a member, so PM with an email address and I'll send 'em.

Isn't AK a fantastic place...:yes:

Opus 7 is coverd in Sams Photofacts, folder 341-16. Gavotte 7 (no 8) is in 399-12. I see that both schematics are at radiomuseum.org - I'm a member, so PM with an email address and I'll send 'em.

I need to send you a real version of the zenith amplifier 7B31 schematic.

It was all wrong. In major places.

The power supply is totally off the chart retarded.

The output transformer primaries are labeled backwards. The input amp/ phase inverter has wrong value parts in it.

I recently rebuilt a Telefunken Opus 7. I would NOT recommend that a novice do this rebuild.

There are MANY paper/wax caps that will need to be replaced. The electrolytics will be easy (sort of), but getting to all the small paper caps literally took the use of surgical tools to fish them out, and to help wire in replacements. A very long, pointed, soldering iron tip will be necessary, as well as locking forceps to keep other wires out of the way while you work.

The main rectifier is a selenium rectifier, built into a can that looks very much like a big power supply cap. I built a bridge out of 1.5A, 600V Fast, soft-recovery diodes to replace it.

Unless you want to either cut, or undo the wire wrapping on all the speakers, you will not be able to fully separate the speakers, and their board, from the chassis. There is JUST enough slack in the wire to access everything, but it doesn't make the job easy.

Back to power supply caps, you can get by with a bit larger value since the unit is solid-state rectified, and you will want to go with at a least 350V rating. The schematic shows B+ Voltages in the 275V range, but that's back when line Voltage was nearer to 110V instead of 120V.

You will want to test all the tubes and make sure they are all in good shape before you begin, so that you don't try to fix problems that turn out to be tube-related.

If they have not been started up in a long time, and if you have not started them up yet, PLEASE find someone with a variac to do it! bringing the voltage up slow will save a lot of heartache of there is something wrong with the circuit.

I have the schematic around here someplace, but I'll need to scan it.

Also, be aware that the finish on the cases is shellac, not other more "modern" types of varnish. If any of that needs restoration, read up a bit on working with shellac finishes.

Again, I highly recommend getting good technical help someplace, as I would not suggest this be a first restoration of this sort for anyone.

You may or may not realize, but depending on condition, the two radios you just picked up may together be worth a grand, plus or minus a bit.

I'd love to see photos, here's the one I restored:

78329

I recently rebuilt a Telefunken Opus 7. I would NOT recommend that a novice do this rebuild.

There are MANY paper/wax caps that will need to be replaced. The electrolytics will be easy (sort of), but getting to all the small paper caps literally took the use of surgical tools to fish them out, and to help wire in replacements. A very long, pointed, soldering iron tip will be necessary, as well as locking forceps to keep other wires out of the way while you work.

The main rectifier is a selenium rectifier, built into a can that looks very much like a big power supply cap. I built a bridge out of 1.5A, 600V Fast, soft-recovery diodes to replace it.

Unless you want to either cut, or undo the wire wrapping on all the speakers, you will not be able to fully separate the speakers, and their board, from the chassis. There is JUST enough slack in the wire to access everything, but it doesn't make the job easy.

Back to power supply caps, you can get by with a bit larger value since the unit is solid-state rectified, and you will want to go with at a least 350V rating. The schematic shows B+ Voltages in the 275V range, but that's back when line Voltage was nearer to 110V instead of 120V.

You will want to test all the tubes and make sure they are all in good shape before you begin, so that you don't try to fix problems that turn out to be tube-related.

If they have not been started up in a long time, and if you have not started them up yet, PLEASE find someone with a variac to do it! bringing the voltage up slow will save a lot of heartache of there is something wrong with the circuit.

I have the schematic around here someplace, but I'll need to scan it.

Also, be aware that the finish on the cases is shellac, not other more "modern" types of varnish. If any of that needs restoration, read up a bit on working with shellac finishes.

Again, I highly recommend getting good technical help someplace, as I would not suggest this be a first restoration of this sort for anyone.

You may or may not realize, but depending on condition, the two radios you just picked up may together be worth a grand, plus or minus a bit.

I'd love to see photos, here's the one I restored:

78329
Hello Don;
Thanks a lot for such explanation.
First of, your BEATIFUL radio is just like mine. (wood grille etc.)
Yes, you could say I'm overwelmed with the task at hand.
Here's my issue, I live in Miami Florida and I've done a search as far as 40 miles around and I have yet to find a single person who still restores tube radios. (They have all either retired or sadly enough died!!)
Paying shipping to and from, plus restoration fees is going to be very hard for me. That's the main reason why I've already taken the back and bottom cover off more than a dozen times (on the Opus) just to get a feel for things!!
Everything on it looks very complicated and although I consider myself half smart and handy, I obviously realize that I should somehow seek hands on experience either from you guys or somebody around my area.(but then again.....)
I'm even kind of hoping that someone would have some sort of parts list from when they ordered the resistors, caps, diodes etc. for their project. (who knows right?)
The cabinet would not be a problem, I have a cousing who owns a custom cabinetry shop ( Cabs. for private jets, yachts etc.) and he's local.
So back on the electronics part of things I would be asking lots of questions, so please be patient with me and hopefully one day mine would be half as pretty as yours!
Thanks again Don
Regards
Victor

Hello Don;
Thanks a lot for such explanation.
First of, your BEATIFUL radio is just like mine. (wood grille etc.)
Yes, you could say I'm overwelmed with the task at hand.
Here's my issue, I live in Miami Florida and I've done a search as far as 40 miles around and I have yet to find a single person who still restores tube radios. (They have all either retired or sadly enough died!!)
Paying shipping to and from, plus restoration fees is going to be very hard for me. That's the main reason why I've already taken the back and bottom cover off more than a dozen times (on the Opus) just to get a feel for things!!
Everything on it looks very complicated and although I consider myself half smart and handy, I obviously realize that I should somehow seek hands on experience either from you guys or somebody around my area.(but then again.....)
I'm even kind of hoping that someone would have some sort of parts list from when they ordered the resistors, caps, diodes etc. for their project. (who knows right?)
The cabinet would not be a problem, I have a cousing who owns a custom cabinetry shop ( Cabs. for private jets, yachts etc.) and he's local.
So back on the electronics part of things I would be asking lots of questions, so please be patient with me and hopefully one day mine would be half as pretty as yours!
Thanks again Don
Regards
Victor

Thanks Victor. The radio actually isn't mine, but belongs to a good friend who has turned out to be a good customer. :tresbon:

The great thing is, the Opus 7 sounds AMAZING when working properly! I'll look at the schematic, and try to remember which caps are necessary to replace. The schematic has things labeled C1, R27, etc., but since it's point-to-point wired, that doesn't help much. There will be a LOT of wire tracing to do. For instance, the wires going from the high-voltage section of the transformer into the bridge rectifier are so short that finding them is difficult, but the next thing on the schematic after the rectifier is, of course, the filter caps, but they are on the opposite side of the radio!

I'll try to get a good scan soon, but a good scan will be a HUGE file, may have to email it later.

I've sent schematics for both radios.

I've sent schematics for both radios.

cool, the original doesn't quite fit on the plate of my scanner . . .