Loud and clear on the white plastic capacitors. All electrolytics will be replaced minus the 2 main filter caps. They were replaced shortly before I acquired it.
There are 4 "cement" resistors (I call them) at the lower left. 2-27ohm 5 watt and 2-50ohm 10 watt. They will be replaced as well. I tend to replace resistors rated 2 watts and up. Can't be trusted after 40+ years.
I have replaced the old coax in some recent "upgrades" I have done for other folks recently. The coax that was pinching the 12vac wire from the transformer has a foam dielectric. Never have liked that stuff! In my experience it doesn't "play well with heat". I have used RG-313. It has a Teflon dielectric, is small and holds up to heat well. (A real space saver too!)
Some people may ask why I fool with these sweep tube amps. For me they are a great cheap learning tool. Yes, sweep tubes can be hard to come by, but I have found that if the tubes are treated right and not pushed hard, they will give good service. Not unlike a 70's car or truck with 100k miles, these amps will require a "tune-up". To me this means replace all electrolytics, all rectifier diodes, all higher wattage resistors, cleaning relay contacts, flux removal from traces as well as a close inspection and repair of questionable traces, resoldering high voltage traces, replacement coax jumpers and (sometimes) new SO-239 connectors too.
This particular amplifier kind of "fell into my hands" for $125.00 and was working great. I don't know of anywhere else you can get 1/2Kw for that kind of money. I believe it to be well worth the investment to "renew" this classic!
If my operation of a sweep tube amplifier offends anyone, please place me on your ignore list.
Nomad,
Thanks for the tips on this one. I last owned one of these in 1979 and I think it is a great classic piece to restore!
73's
David
