Hi Marv,
Is the configuration you are speaking of the one that is so commonly
used in CATV "tap" couplers (I don't have the Sabin book here)? That
configuration can be easily made to produce flat coupling and good
directivity over two decades of bandwidth. I have always been surprised
that this circuit doesn't appear much in amateur literature. It is very
simple to build.
73 de Mike, W4EF...................................
----- Original Message -----
From: "Radio WC6W" <wc6w@juno.com>
To: <thomas.hoeppe@asamnet.de>; <amps@contesting.com>
Sent: Thursday, October 07, 2004 6:01 PM
Subject: Re: [Amps] Power metering in linears
>
> On Wed, 6 Oct 2004 20:38:59 +0200 "Thomas Hoeppe"
> <thomas.hoeppe@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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