Re: P3: a modest proposal for QSY

Posted by Guy, K2AV on Aug 13, 2010; 2:12pm
URL: http://elecraft.85.s1.nabble.com/P3-a-modest-proposal-for-QSY-tp5410950p5420140.html

+ and - 100 Hz has worked quite well for breaking some pileups, and
still well within the +/- 250 Hz that puts one into the serious
annoyance category for the fellows up and down frequency.

While it really is nice to know that the P3 *WILL* set you fairly dead
on for digital signals, the degree of accuracy being discussed in this
thread, IMHO, is a far greater sharpness than needed to tack up the
note in a CW contest. More like measuring board widths with a
micrometer.

For those who simply don't have the tone sensitivity to set zero beat
by ear, even 50 Hz would be way better than some who apparently can't
get it within 250 Hz and then SPOT the misread.  Such an individual
will be able to set themselves just about spot on.

But even the it's-only-as-good-as-plus-or-minus-fifty scenario put
forth by the gentleman would have been good enough for a CW contest
and certainly would not have been the implied "tragedy".

EITHER what he said or what you said bring it into clear usefulness
for my purposes.  I'll take the better without any complaints.  : >)

73, Guy.

On Fri, Aug 13, 2010 at 9:17 AM, Bill W4ZV <[hidden email]> wrote:

>
>
> Guy, K2AV wrote:
>>
>> Actually...
>>
>> In a CW contest, where following packet spots can put you on the exact
>> same frequency with all the other braying lemmings, contributing to
>> your signal's non-pickoutable status at the other end, being off the
>> crowd frequency by 20-50 hertz is a SUCCESSFUL strategy to break
>> through the pile, practiced ON PURPOSE by top CW contest operators. If
>> you are following CW packet spots, best to set your XIT up or down
>> 20-30 Hz and leave it there.  DON'T ever use zero offset chasing CW
>> packet spots.  (It will NOT bother me in the LEAST if all those who
>> read this think such an assertion is nonsense and never try it out.  I
>> have outlined one of my competitive edge secrets, and I WON'T mind if
>> you DON'T use it.)
>>
>> So being within 50 Hz is QUITE adequate and USEFUL.  And despite given
>> what seems to be being played as some failure of the P3, one DOES
>> still have the K3 tuning knob to very quickly adjust to perfect
>> centering for RTTY, and digital modes.  On the K3, it's the big
>> easy-to-use same-size-as-the-maxi-boxes knob.  For other transceivers,
>> consult owner's manual for location and instructions for tuning knob.
>>
>> 50 Hz off will still be within the audible passband on the NARROWEST
>> K3 passband setting.  Most contesters will use something like 200 or
>> 250 for search and pounce, especially for chasing packet spots.  Many
>> of these spots will be off 100 or 200 Hz, in addition to carrying
>> blown calls, which is why the need for a quite wider bandwidth than 50
>> Hz for any kind of search and pounce operation.
>>
>
> I strongly disagree.  Ideally, the P3 should send the receiver VFO (not the
> transmitter) to exact zero-beat (as CW Skimmer does).  If you *then* choose
> to set XIT for a consistent + or - 50 Hz offset, that's very easy to do.  If
> the receiver does not go to zero beat, you have no way to set your
> consistent 50 Hz offset and in fact will be randomly between 0 and 100 Hz
> off, depending on which side of zero-beat the P3 sends the K3 to (+50 +50 =
> +100, and -50 +50 = 0, where VFO is the first number and XIT is the second).
>
> The lack of true zero-beat capability is the major missing piece in the P3
> and is why I'll continue to use CW Skimmer (even with its 24 kHz limitation)
> with my K3.  Alan is very aware of this need, there are multiple
> implementation possibilities, and I'm sure he'll find the best solution.
> But I would not like for him to walk away from this discussion thinking true
> zero-beat capability is not needed.
>
> 73,  Bill
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/P3-a-modest-proposal-for-QSY-tp5410950p5419946.html
> Sent from the [K3] mailing list archive at Nabble.com.
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