[Amps] Power metering in linears

[Radio WC6W]

On Wed, 6 Oct 2004 20:38:59 +0200 "Thomas Hoeppe"
<thomas.hoeppe at asamnet.de> writes:
> Hello technicians,
> 
> I was adding a power meter to a new homemade linear. 

<snip>

> The problem: The output voltage for a given power is the same from 
> 40-10m, but nearly null on 80m and different on 160m.
> 
> Then I tried the design from the linears in the W6SAI handbook. They 
> use Amidon 50-6 toroids. The output voltage ón 160 is about 1/2 of 
> the voltage on 10m. 
> 
> 
> Thanks!
> 
> Tom, DJ5RE

Hi Tom,
   A better circuit configuration is the cross-coupled transformer
directional coupler.

   It eliminates all the capacitors and their adjustments.

   I don't know if anyone has described it in the Amateur literature but,
a good explanation may be found in "Single Sideband Systems & Circuits"
by Sabin & Schonike, 1987, pp. 498-99.

   Incidently, to cover as low as 160 you would want to employ a low mu
ferrite rather than a powdered iron core.   FT-50A-61's should suffice.

73 & Good evening,
   Marv  WC6W






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