[TenTec] Purpose of 250 Hz 8 pole filters

[Dr. Gerald N. Johnson]

On Mon, 2007-10-22 at 00:32 -0400, k8vf_mark at centurytel.net wrote:
> "Matching the received signal pitch to the transmitted has been a problem
> with narrow receivers for a loooong time. I had a Hint & Kink published
> in QST back about 1981 after a frustrating FD with few answers because
> the rig didn't transmit where I listened. After I borrowed a second
> receiver to adjust RIT so the two signals matched I made many contacts."
> 
> This is something which is a real issue.
> MANY guys don't bother to check to verify that they are transmitting and 
> receiving on the same freq. Sometimes, WAY off!(and NOT just because they 
> liked a different pitch than I.)

Well it can be because of liking a different receive pitch than the
built in transmit offset. In some radios that offset is adjustable, in
some its not.

That's where a narrow filter in one of the IFs of a Corsair or Omni V/VI
allows customizing the receive pitch, but without also adjusting XIT it
can lead to unwanted splits.
> 
> I have worked many guys in contests who were just obviously either using RIT 
> or hadn't a clue about how far off they were.
> We should all check this item periodically on our rigs. It wouldn't be 
> tolerated on SSB. Cw ops shouldn't either.
> It is too easy to check.

It is easy to check with a second receiver. Otherwise the only hint is
lack of answers during a CW contest, but that doesn't solve the question
of who is off the most?
> 
73, Jerry, K0CQ