[amsat-bb] Re: Listening on USB when operating CW

7 Feb 2014

      Hi Tim,
I completely agree that different methods of Doppler shift correction
yield slightly different results.  The "one true rule" is a good
source for guidance however some don't follow it -- even remotely.   I
do apologize if my generalization rubbed you the wrong way.
Since your direct email indicated to me you adjust your transmit
frequency on AO-7 mode B, that would indicate you are following a good
practice of correction.  Likely meaning you are NOT one of the
stations who drift during their entire sequence of calling CQ for five
minutes.....  Not everyone plays nice in the schoolyard.  I've been
known to screw up and probably am not immune from it in the future.
I still wonder if the offenders listened on USB would they realize
they've come onto a frequency being used by two or more stations
engaged in a voice QSO?
73
Clayton
W5PFG
On Fri, Feb 7, 2014 at 3:45 PM,  [email protected] wrote:
...
I'm hoping this post makes it to the AMSAT-BB, although I have sent Mr.
Coleman a longer response directly.
I have to take issue with this statement, Mr. Coleman, which begins your
second sentence in response to Mr. Ng:
"A station not adjusting properly for Doppler shift...."
Computer-control stations and manual-control stations are adjusting for
Doppler differently. I have done - and will continue to do - both. In my
opinion, neither is incorrect; they simply differ from each other.
73 and God Bless,
Tim - N3TL
Evansville, Ind. - EM68
-------- Original Message --------
Subject: [amsat-bb] Re: Listening on USB when operating CW
From: Clayton Coleman [email protected]
Date: Fri, February 07, 2014 2:04 pm
To: "Ng, Peter" [email protected]
Cc: "[email protected]" [email protected]
Peter,
That is correct and what I have attempted to describe. A station not
adjusting properly for Doppler shift will appear to "move" across the
passband into stations who are making corrections. (voice or CW)
There are several categories for correction, as I see it by order of
occurrence...(and there may be more)
1 - People who use "full" Doppler correction via software, adjusting
both TX and RX to stay on the satellite's frequency.
2 - People who use "half" Doppler correction by tuning the higher of
two frequencies. This is common for people who are portable or want
the simplest method of staying on another station. In the mode, you
will move slightly. I do this often in the field. It's not perfect.
3 - People who use "TX only" correction. I see this often and I
believe it's an incorrect practice to always tune TX because sometimes
that means on mode J you'll likely move across QSO's in progress.
4 - Probably the least common I observe, people who use "full" Doppler
correction manually. I believe it is a little more difficult to do
this on fast moving LEO's, especially on CW.
My original email was trying to discover whether or not listening on
USB while transmitting on CW might make it easier for "CW drifters" to
know they are part of a problem. Occasionally when this problem
occurs with USB voice, the perpetrating stations are not able to hear
well enough to know they are causing a problem.
73
Clayton
W5PFG
On Fri, Feb 7, 2014 at 11:33 AM, Ng, Peter [email protected] wrote:
...
Yes, the frequency in use by the CW station that is not adjusting for
doppler will appear to be moving for stations that are adjusting for
doppler....right?
Peter ve7ngp
-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of John Becker
Sent: February 7, 2014 09:27
To: [email protected]
Subject: [amsat-bb] Re: Listening on USB when operating CW
On 2/7/2014 11:18 AM, Ng, Peter wrote:
...
Correct me if I'm wrong, but doesn't automatic doppler corrections
dynamically change your frequency to compensate for doppler? Would this mean
anyone engaging in doppler correction are actually drifting into a stable
frequency?
by "stable" do you mean a freq already being used?
John, W0JAB

Sent via [email protected]. Opinions expressed are those of the author.
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