Re: Listening on USB when operating CW
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, tim@n3tl.com 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 kayakfishtx@gmail.com Date: Fri, February 07, 2014 2:04 pm To: "Ng, Peter" Peter.Ng@bccdc.ca Cc: "amsat-bb@amsat.org" amsat-bb@amsat.org
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 Peter.Ng@bccdc.ca 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: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of John Becker Sent: February 7, 2014 09:27 To: amsat-bb@amsat.org 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 AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I think Patrick's comment about needing to use USB when operating CW is the key one. I also, for the very few times I have attempted CW on satellites, needed to use USB on the downlink so I could keep my return signal audible. CW in both directions, even with computer control, is more frustrating than it's worth, and our satellites aren't so weak as to need the narrowest of bandwidths to pull the signal out of the noise.
I do agree that USB would definitely help with hearing what's going on around you, and I expect a nice dongle-based (waterfall) receiver would be even better.
Greg KO6TH
Clayton Coleman wrote:
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, tim@n3tl.com 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 kayakfishtx@gmail.com Date: Fri, February 07, 2014 2:04 pm To: "Ng, Peter" Peter.Ng@bccdc.ca Cc: "amsat-bb@amsat.org" amsat-bb@amsat.org
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 Peter.Ng@bccdc.ca 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: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of John Becker Sent: February 7, 2014 09:27 To: amsat-bb@amsat.org 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 AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
participants (2)
-
Clayton Coleman -
Greg D