I would check the continuity of the two AF interstage xfmrs, primary and secondaries. Check the tubes for filament continuity.
Connect a high-impedance speaker, and bring it up slowly with a variac.
Nothing can be too wrong with this set except the power supply - filters, power xfmer. Go slow.
:I just bought a really great K-21 and I want to restore it. I have the tubes and I plan to rework the electronics. Does anyone have any helpful tips for this project? Thanks
Nice radio. I like the pressed wood and lion feet. If you don't already have it there is a matching speaker with the same feet.
Follow Doug's recomendations and you won't go wrong.
You can take apart the entire radio cabinet for refinishing. It's held together by corner metal brackets. Original finish is a white material. It can easily be removed if you would rather use stain or other finish.
Norm
:Steve: interesting AC set. 4 RF stages, det, 2 AF stages, plus rectifier.
:
:I would check the continuity of the two AF interstage xfmrs, primary and secondaries. Check the tubes for filament continuity.
:
:Connect a high-impedance speaker, and bring it up slowly with a variac.
:
:Nothing can be too wrong with this set except the power supply - filters, power xfmer. Go slow.
:
:
::I just bought a really great K-21 and I want to restore it. I have the tubes and I plan to rework the electronics. Does anyone have any helpful tips for this project? Thanks
To date I have never had any real problems with the power supplies on these old TRF sets.They don't use electrolytics, so that is not really an issue. However, the variac is a good idea. You might want to use some cleaning spray on all the controls and tube sockets - surface corrosion can mean the difference between a working and a non-working radio.:I just bought a really great K-21 and I want to restore it. I have the tubes and I plan to rework the electronics. Does anyone have any helpful tips for this project? Thanks