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Old August 25th 13, 03:26 PM posted to uk.radio.amateur,rec.radio.amateur.boatanchors,rec.radio.amateur.homebrew
Ian Jackson[_2_] Ian Jackson[_2_] is offline
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First recorded activity by RadioBanter: Nov 2007
Posts: 568
Default Crystal phasing & single signal reception

In message , gareth
writes
"Ian Jackson" wrote in message
...
In message , Scott Dorsey
writes
gareth wrote:
"Peter Able" stuck@home wrote in message
IMHO, Peter's reply is the correct opening statement of a response to
your
rather unstructured question. If you cannot then use this statement to
seed and to refine your own thought process, it might be more helpful
if
you elaborated the point that you think he is missing.

Thanks. but the subject matter seems to have WHOOSHED over your head.

Mine too, I don't really understand what you're asking. The crystal
filter
is a bandpass filter. The phasing control affects the symmetry of the
filter somewhat (but not really all that much).
--scott


The crystal by itself has a natural 'blow-suck' signal throughput, with a
sharp notch just HF of the peak. The phasing control capacitor should be
able to move the notch to the LF side of the peak, and also (to a limited
extent) to move the notch a little closer to the peak (on either side).


Ian, with your greater experience than mine, it is the concept of
single-signal reception in which I am interested.

Have you any clues about that, please?

The only clue I can offer is that 'single-signal reception' is vague -
but presumably self-explanatory, ie the filtering is very narrow,
enabling you to receive only one signal (unless you have more than one
on or very close to the same frequency). It's a term that I recall being
around when I were a lad, but I can't say I've heard it much since. I
guess it's been replaced by more scientific descriptions of how good the
filtering is.
--
Ian