Gosh, don't know how those thousands of users were so impressed....
:) :) :) :(
73, Walt
On Thu, 15 Apr 1999 11:08:45 -0500 "Dr. Gerald N. Johnson, P.E."
<geraldj@ames.net> wrote:
> I disagree that Collins mechanical filters are better. They are NOT
> better for the real world with static and rapid time noise. They are
> super for radio interference rejection and have a terrible time
> response. The will ring for long enough that line noise is not heard
> through them as a buzz, just as a greatly raised white noise level. On a
> scope the filter ringing stays there to fill in the gaps between arcs
> that happen every 1/360th cycle (from a three phase power line). The
> output of a Collins filter from lighting static is a CRASHHH that goes
> on and on. The output of a Tentec filter is a click... There is a
> difference and Tentec does it better than Collins. I have both. And
> nearly all the rest of the world's crystal filters emulate both the
> frequency and time responses of the Collins filter (with emphasis on
> shape factor, neglecting time response) so users of those filters in
> rice boxes have to quit radioing when there's a bit of static because
> all they hear is extended crashes while Tentec users hear only clicks
> from lightning static.
--
FAQ on WWW: http://www.contesting.com/tentecfaq.htm
Submissions: tentec@contesting.com
Administrative requests: tentec-REQUEST@contesting.com
Problems: owner-tentec@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|