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Repairing the 16309 Peerless output transformer that lives in the Heath W5m amp.

michaelsamra

michaelsamra

michaelsamra
Banned
Has anyone had any success unpotting the 16309 Peerless transformer and fixing the winding? Most of these transformers have the center tap open to one of the plate-screen windings of the KT66s. Both sides have continuity between plate and screen of each individual tube but only one tube is connected to its center tap..That is the problem with most.Has anyone had any luck finding the severed winding?
 
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Hello!

I asked the same question last year. I had 2 amps with open outputs. After lots of digging around I was told told it was a lost cause. If you can successfully do it, please take pictures! Robert
 
I would suggest replacing it too. I have a tad bit of experience with Heathkit stuff. I have re-melted, if you will, potting material before. Not worth the trouble if you ask me. Just my 2 cents.
 
Guys
The reason I want to repair the 16309 is,I like the sound that transformer produces even tho technically transformers don't produce sound.I would imagine the nickel plating and the higher impedance has a lot to do with it being it's very conducive to that circuit design.I have two theories as to why they fail.The first is,people don't change those couplers out and they leak DC,therefore making the output tubes draw grid current and going beyond the rating of the transformer.The other is,the old tar breaks down and lets moisture.I have 27 of these amps all with the 309 trannies and everyone I had taken down and repotted as well as change the couplers,has not failed.I have 6 units with open trannies right now.
If we can get a few guys to split the reverse engineering costs with Heyboer,I think it would be worthwhile with so many out there.I am still going to see if I can reconnect the broken wire.Does Magnequest sell the 309? That might be another option.
 
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:lurk: Interesting problem and well known. What is your feeling about the larger replacement Peerless transformer used on later W5M's?
 
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The 458 are good trannies although I don't know if they produce a similar sonic structure in the W5 amps. They are a lower impedance by 1k and they don't have the nickel plating in the center.I have a pair here I am rebuilding for a guy and I will let you know how they sound.I am using motor run caps as well as unilytic poly films and paper in oil coupling caps and a combo of KOA SPeers and Riken resistors.
 
funny when I first read this post, I was gonna say the guy to ask would be Mike Samra :)
 
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