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Re: [Amps] Power metering in linears

To: W4EF@dellroy.com, thomas.hoeppe@asamnet.de, amps@contesting.com
Subject: Re: [Amps] Power metering in linears
From: Radio WC6W <wc6w@juno.com>
Date: Fri, 8 Oct 2004 13:54:00 -0700
List-post: <mailto:amps@contesting.com>
On Thu, 7 Oct 2004 18:59:28 -0700 "Michael Tope" <W4EF@dellroy.com>
writes:
> 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...................................
> 

>Hello Marv,
> 
>this sounds very interesting. I have bought an old book from the ex DDR
(Y2)
>army, where I found a description of a coupler without C's. May be it's
the
>same.
> 
>Thanks for reply!
> 
>Tom, DJ5RE


Hi Mike & Tom,
   Perhaps...

   Visualizing the thing as a 4 port device.

    Port 1 is the RF input
    Port 2 is the RF output
    Port 3 is the Forward sample
    Port 4 is the Reverse sample

   Two identical transformers with 32 turn secondaries (for -30 db
coupling) are employed.

   The single "turn" primary of the first transformer is connected
between Ports 1 & 4.
   The secondary of the first transformer is connected between ground &
Port 3.
   The single "turn" primary of the second transformer is connected
between Ports 3 & 4.
   The secondary of the second transformer is connected between ground &
Port 2.
   Phasing of the windings is consistent with the connection order
detailed above. 

   For cable TV use, I suppose the reverse port is terminated (w/ 75
ohms?) to make a 3 port critter.

   For 50 ohm power measurement, the sample ports need to be terminated
in 50 ohms non-inductive of suitable power rating.  A rectification of
this sample may be used to drive a meter or other indicator.

73 & Good afternoon,
   Marv  WC6W








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