Some help with my Tekefunken radio

[radix39]

I'm trying to get some help in fixing a few small issues with my Opus 7 (I think?). Pretty much everything works great, AM, FM, SW, the eye, all dials, switches, etc. The case is in excellent condition. I've only noticed a few small things:

1.) The bass sounds kind of "farty". Thats the best way I can describe it. Instead of a THUMP for a beat, you'll hear more of a fart sound. Its not too bad, but i'm sure it can be fixed. Only problem is, i'm not sure how. Do I need to replace the tubes? Something else? What kind do I need, and where can I get them? More importantly, how much would they cost?

2.) The unit gets next to no reception unless I short (ie. tie together) these two extenal plugs that come out the back of the unit. I assume these are supposed to plug into an external antenna, but since I don't have that antenna, it gets no reception until I artifically create one by shorting those 2 wires. Am I correct in assuming this? Is this how its supposed to work, or is there something wrong here?

I would like to fix these problems myself, if possible, since I have a lot of fun doing this kind of stuff, and I always love learning new things. But if you guys think its beyond me, maybe you can recommend a good place to get it fixed somewhere here in NYC.

Oh, here's a picture so you can see it too.

[Nolan Woodbury]

There's lots of ways to go about finding out what's wrong with your Tele Radix39, and although there are more qualified techs here, I'll tell you what I've learned.

The old adage is; if the radio is working (like yours) hum indicates capacitor failure and poor gain (volume) or reception often indicates weak or failing tubes. That is JUST a general rule of thumb, and by no means the final answer, but you've got to start somewhere. The poor bass response on your radio sounds like a reception issue to me, but it could be anything.

That said, I'd begin by carefully pulling the chassis, check the tubes and check for leaking capacitors. Not really knowing what's inside your Telefunken (I do Zenith mainly) when I get a radio in, I'll check the easy to spot paper caps. If they're sticky, they're bad, but even looking normal they can still be bad, and many folks just change them all while the radio is apart. I've been doing this, I check the value (if marked) and replace with a new one, one by one, so I don't get mixed up. Many sets have a large, stacked (or linked) selection of shielded capacitors on top with the tubes, and you'll need a schematic to check the total value.

List your tube selection and order from either www.tubedepot.com (who I found on this site) or the excellent folks at AES: http://www.tubesandmore.com. The site is excellent. Cost? That's up to you to find out...I still have radios apart I need to fix! Expect anywhere from $3.00 all the way to $15-20.00 for the big output jobs.

Dust the chassis, clean the tube pins (and the socket!) and try it again. Surf the web for speakers or a suitable crossover if needed. That's about all I know to say, but there are Telefunken owners in this group that'll probably have better suggestions or leads. Reception is a tricky issue; I've strung yards of cord to no avail, but did finally put together a pretty nice antenna, using the old TV pole the previous owner of my house installed in a cement base. I can pick up AM stations in the Midwest and Southeast with my H-845 after dark very clearly.

Good luck. I'm sure some of the others will chime in with advice and info-

[Phil Nelson]

If the radio basically works, then replacing all of the tubes is a waste of money.

I have a Telefunken Gavotte 9, similar to yours but not quite as elaborate.

It's possible that you have no antenna connected, or something misconnected. In that case, of course you would have poor reception including cruddy audio.

If you can post a photo clearly showing the back, maybe we can help you sort things out.

It's also good medicine to replace the old electrolytic and paper capacitors in any radio of this vintage. The article at http://antiqueradio.org/recap.htm provides info about replacing capacitors.

Note that European radios like this often have quite cramped circuitry and use small components. You may also be looking at a schematic that is in German (duh) and which uses somewhat different symbols than American schematics. Not a good starting project if you have never done this kind of work before.

Originally Posted by radix39

maybe you can recommend a good place to get it fixed somewhere here in NYC.

You could contact a nearby radio collector club and ask for a recommendation. See the list of clubs at http://www.antiqueradio.com/clublist.html.

The NJARC is a very active club, which sometimes runs clinics where people can bring in old radios for on-the-spot diagnosis/repair.

[Chad Hauris]

In addition to these other good suggestions, we have seen woofer foam degradation and other problems with speakers on Grundigs causing bad sound.

[Nolan Woodbury]

Phil, thanks for posting the antiqueradio.org link; what an outstanding site! I read the 'replacing capacitors' section and learned a few things I didn't know...like proper placement (for example; avoiding the RF section when changing large electrolytics) and insulation. I don't know if the author, Phillip Nelson posts here, but he should-

Oh, btw radix39, I was on surfing justradios.com today and noticed they sell schematics for European radios. You might want to check that out before pulling your Tele apart.

Again, thanks for pointing out an outstanding site Phil. That one went right to the top of my bookmarks.