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phase/fire

Subject: phase/fire
From: W8JITom@aol.com (W8JITom@aol.com)
Date: Thu Jun 6 22:59:45 1996
Hi Rich,
In a message dated 96-06-06 18:02:17 EDT, you write:

>I'm not sure how well the QRN SQUASHER will work as described in CQ
>June, but the phase shift circuit will shift the phase and not just
>by 180 degrees. This circuit was used in the old satellite
>range/range rate gear for phase calibration. 

That's not true. The circuit as published in CQ will absolutely NOT shift
phase, since there are no components in series with the RF parth from T1 that
shift phase. The circuit simply gives a choice of a 180 degree shift or no
shift.

In order to shift phase, the top signal path leading to R2 must contain
components or circuitry that shifts phase at a different rate than the lower
path to R2. The circuit contains no such components or circuitry. If you look
at it carefully, you'll see it is symmetrical. Being symmetrical, it can not
rotate the phase. 

It does look, at a glance, similar to a bridge type phase shifting circuit.
But unfortunately it isn't one. 

73 Tom

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