[Amps] RF deck plate tests (simulating HV?)

Bill, W6WRT dezrat1242 at yahoo.com
Thu Sep 10 16:01:36 PDT 2009


ORIGINAL MESSAGE:

On Thu, 10 Sep 2009 22:49:37 +0100, "Andy GD0TEP" <andy at gd0tep.com> wrote:

>
>OK, a simple question... On testing an RF deck prior to applying anode
>voltage, I want to simulate the voltage by using a resistor and then use my
>MFJ on the RF out socket to set up the load/tune.
>
>How do I work out the value of resistance required?

REPLY:

Divide the plate voltage (under load) by the plate current in amps, then divide
that by a factor of about 1.6. I say "about" because the exact factor depends on
how the tube is biased. The closer the tube is biased toward class A, the
smaller the factor and the closer toward class B the higher the factor. Most
modern amps run class AB2 and will be somewhere between 1.5 and 1.7.

Any recent ARRL handbook will have a further explanation.

73, Bill W6WRT


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