KPA 100 Alignment Question

[David Douglass]

Hi All,

Have just completed my KPA100, and am at the aligment stage.

Regarding the aligment of R6 (Bias set).

The manual says to connect your DMM in series with the positive power lead, with
the + lead of the DMM to the power supply and the - lead to the KPA100 side.

I assume this means I connect the +lead of the DMM to + terminal of the PSU,
and the -lead of the DMM to +pin of the power connecter where it enters the
radio?? Is this correct??

Just for interests sake, what am I actually doing at this stage of the alignment?

Cheers

David, VK2NU
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[Vic K2VCO]

[hidden email] wrote:

> I assume this means I connect the +lead of the DMM to + terminal of the PSU,
> and the -lead of the DMM to +pin of the power connecter where it enters the
> radio?? Is this correct??

Yes.  Make sure it is set up to measure current, not voltage.  Often
this means connecting the test probe to a different jack on the dmm.

> Just for interests sake, what am I actually doing at this stage of the alignment?

You're measuring the current drawn by the transistors as you adjust the
bias voltage.  This sets the proper operating point for the transistors
so that they will not burn up and will produce a reasonable amount of
power with an acceptably low amount of distortion.

--
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco

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