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Model 89 Restoration Suggestions
#1

I started another thread back in summer regarding restoring a Model 96 Lowboy, and am finally ordering capacitors to do so. I have since acquired a Model 89 Code 121 and would like to order capacitors for it as well. I assume I should start with the Bypass bank, Part # 08824 as well as the tone control capacitors. I'd appreciate comments regarding these replacements, and suggestions for anything else I should replace before connecting the Model 89. I now have a Variac to do this.

Also, the Model 89 speaker cone is in tatters, and the cabinet has de-laminated and is chipped badly. I haven't decided to follow through on restoring it and won't until I can try it out and determine how much effort and expense it may require. In the meantime, is there a temporary/test speaker/setup I might use to try this radio? The Model 96 speaker appears to be in wonderful condition, though I don't know that it functions, would it be an acceptable substitute? If not, are there more modern speakers I might temporarily use before deciding to have the original re-coned, provided it's transformer and electromagnet are likely to function appropriately?

Thank you.
#2

Speaker from 96 cannot be used in 89 as the 89 has a single tube output amp and the 96 has two 45 tube push-pull.

Now what you could do is to use a PM speaker connected to the output transformer's secondary. Provided the rest works.

Now what I am not sure of is how you are going to test it considering the radio chassis has not been recapped etc.

So, this said, if by saying all this you are implying you want to try the chassis without making sure first it is fully reconditioned, then I'd strongly urged you not to do this.

As for "I should start from these capacitors" - you should start from ALL capacitors except mica ones. Round up everything electrolytic and paper tubular or backelite caps and start ordering.
#3

If you want to save on shipping costs, check the resistors and add any out of tolerance resistors to your order. I know I've been guilty of doing multiple orders and the shipping costs, and delays add up.

Good luck,
Jon
#4

How bad is the speaker? I'm working on an 89B right now as well, and the cone was very fragile and in tatters. I used a dab of tacky fabric glue on the small tears, and pieces of coffee filter coated in glue for the bigger ones. It sounds better than any newer substitutes I could find (not cheap ones, either). I would fully recommend trying this. Make sure you check the windings before you waste time on the cone, though.

Also, you have to attach a 1100 ohm resistor (or thereabouts, higher is better as the line voltage is higher now than the 30's) of at least 5 or 10 watts where the field coil was, if you choose to go with a newer speaker.

You can test the old speaker if you decide to repair by putting 50-70 volts on the field coil and connecting the output (voice coil) of the speaker to a stereo's output. The impedance is much lower than new speakers, so be careful and use low volume.

Finally, make sure you test all the RF/IF/OSC coils. At least the osc tickler is bad on almost all 89 sets. Kind of a pain to fix, but doable. Don't ask what wire gauge though, I'm still trying to figure that out Icon_razz

Good luck!
Will
#5

It's either 37 or 38 gauge, I don't recall at the moment. But I can tell you that 38 gauge works fine for the tickler winding. Icon_thumbup

--
Ron Ramirez
Ferdinand IN




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