Well, the time has finally come for me to get to work on restoring my aging Telefunk Opus 7. It was given to me by my parents, who got it from a friend who passed away about 10 years ago. Up until now, its mostly just been sitting in a box in the basement for a good 20 years. However, its in overall excellent condition with only a few minor nicks here and there on the wood finish.
The radio powers up and actually runs pretty well. I get excellent reception on FM/AM/SW. Volume knob works, tone controls work (somewhat), tuner eye works great. There is a faint hum in the background that stays at the same level no matter the volume. After about 5 minutes, the quality of the sound starts to sound rather poor and "farty", especially on FM where there is more bass. AM/SW either aren't affected or it isn't as noticeable.
I've gone ahead and opened up the back side. The service manual was unfortunately missing from the small yellow envelope. A fellow AK member was nice enough to send me a replacement copy (thank you!). I've taken some pictures of the innards.
I've cleaned up the dust a bit. Seems like good condition to me. Its pretty obvious that the set has been repaired in the past. Two of the tubes aren't original (unless telefunken ships with other branded tubes). There is a half torn piece of paper on the back with the address of the repair place - somewhere on 3rd avenue in brooklyn ny. I've checked the maps and a repair store no longer exists at that address, so it must have been a long time ago.
From what i've read online, I basically need to replace all the capacitors, and that should be all I need to do. I'm not sure if I need to replace the resistors though. There are a LOT of capacitors and resistors in this set, especially on the underside. I would like to replace them all, but it seems like such a huge undertaking and one small mistake could ruin the entire thing. There also seems to be some bypassing done in previous repairs, which makes it even more confusing.
There are also a lot of strange looking caps on the underside - unusually long and encased in clear plastic. I have to get a closer look to see what these actually are.
Right now, I have a few basic questions -
1.) Do remove the chassis, do i just unscrew the bolts from the underside of the wooden case, and it should come right out?
2.) I would have to disconnect the speaker system to get the chassis out. However, the speaker connections aren't soldered, they are wound several times around a long pin, like this:
It doesn't pull right off and I don't see how to unwind it. How do I get these off?
3.) In the first picture I took, there are 2 oval cans in the center next to the EF89's. Is there anything important under those that I need to replace? The can is bolt on from the underside. How about the circular can on the left next to the antenna? How about the two square looking cases where ECC85 and EABC80 reside in? I have no idea whats inside of those housings and if I should touch them.
I'd like to bring this radio back to "regular" usage. Hopefully I can do that without blowing anything up
