It could even be a useful retrofit into existing rigs -- especially
easy in rigs that run 50 ohm connections between separate boards.
A minor problem I see of putting it in the receive line is there is
usually a LPF filter beyond the TR switch (shared between the Tx and
Rx) designed for 50/75 ohms. Given an 50 ohm load (or particularly a
reactive load) you might see a transformation through the LPF. But a
50 ohm resistive load on the antenna connector will still look like a
50 ohm resistive load on the other side of the LPF.
Still it's easy to do: a resistive bridge, a pulsing noise source (or
even a continuous one, but the former is easier to hear) and some
switching in out (and turning off the noise source).
On Sep 30, 2007, at 9:41 PM, Dr. Gerald N. Johnson wrote:
On Sun, 2007-09-30 at 20:54 -0700, Denton wrote:
I have very often wondered why these newer rigs do not have a
built in noise
bridge!
It sure wouldn't be complex to do... just a bit of switching to insert
in the line and it might well be the receive line so that it never had
to see transmit power...
73, Jerry, K0CQ
--
Kevin Purcell
kevinpurcell@pobox.com
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