[TenTec] Tuning Rigs

[Kevin Purcell]

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 at pobox.com