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Bias Supply Capacitor Replacement

 

Bias Supply Capacitor Replacement

Filed in Vintage Radio on Jan.04, 2015

The HW-16 negative bias supply (-150 volt) has a dual section 20 uf capacitor that needs to be replaced. The Hayseed Hamfest capacitor kit included two 22 uf, 250 volt capacitors to replace this unit.

The old unit is the ugly brown carboard one on the left had side of this picture, just above the transformer.

 
Dual 20 uf capacitor

This was replaced with two separate modern 20uf high voltage electrolytic capacitors. Note that their negative sides are connected together, and the two positive sides are separate.

 
New 20 uf capacitors

While working on the radio, I was kind of in a an ongoing clean-up mode. I looked over all of the connections, and picked out those that were particular bad to replace. Previous owners had burned several of the wires’ insulation with a hot soldering iron, particularly around the bandswitch. For these, I installed new wires.

 
Old, burned wires

The new wires look much better.

 
New wires on bandswitch

RF Transformer connections  

 
New wires on rf transformer

 

 


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