[TenTec] vague answer to the triton audio filter question

[geoffrey mendelson]

On Jul 27, 2010, at 12:47 AM, Mike Hyder -N4NT- wrote:

> I believe when the 544 is switched to CW one stage of the filter is  
> active.
> The second CW position uses all stages.  The 544 AGC voltage is  
> derived from
> audio.  The Ten-Tec filter appears in the audio string before the AGC
> sampling point.  So to be properly effective, an added audio filter  
> needs to
> be put into the audio circuitry before the AGC sampling.  If this is  
> not
> done, then signals outside the passband of the filter can still pump  
> up the
> AGC voltage.



That's why I suggested the MFJ filter. Although it's on or off, it's a  
tiny circuit board that is designed to go into a radio that is still  
sold. It plugs in but you could easily solder wires to it. The  
connections on it are DC, audio in, audio out and ground, which would  
probably do the job,

That's also why I did not mention that IMHO just about any DSP filter,  
including the Radio Shack ones I bought in the mid 1990's would do  
better. Any external filter would be outside the AGC loop, which would  
cause pumping and false S readings from nearby signals.

Geoff.
-- 
Geoffrey S. Mendelson,  N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must  
order dessert. As part of the socialized health plan, you are  
forbidden to eat it. :-)