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Matchless Clone

12/3/2003 3:42 PM
Bob DeRosa	Matchless Clone I’m starting to build my HC-30 clone and I have a couple of questions regarding the cathode resistors on the power tubes. On the schematic I’m working with there is a single 62ohm resistor for Hi power (4 tubes) and the 62ohm in put in series with a 68ohm (for a total of 130ohm) for Low power. In a previous thread “Cooling down a Bad Cat” there was talk of using larger resistors to get the tubes into the 12W dissipation range (down from 16W I think) but there was no mention of what those values would be. Any suggestions ? Also, why would the two resistors be different ? I expected the half power resistance to be exactly double the full power resistance.

12/3/2003 3:42 PM

Bob DeRosa

Matchless Clone

I’m starting to build my HC-30 clone and I have a couple of questions regarding the cathode resistors on the power tubes.

On the schematic I’m working with there is a single 62ohm resistor for Hi power (4 tubes) and the 62ohm in put in series with a 68ohm (for a total of 130ohm) for Low power.

In a previous thread “Cooling down a Bad Cat” there was talk of using larger resistors to get the tubes into the 12W dissipation range (down from 16W I think) but there was no mention of what those values would be.

Any suggestions ?

Also, why would the two resistors be different ? I expected the half power resistance to be exactly double the full power resistance.

Replies:

Dirty My suggestion is to use a common 4-... -- 12/3/2003 4:02 PM