I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2
Great! This PSK31 TX-only software for PSAT PSK-31 solves three problems! 1) as a separate TX-only program, it lets everyone run FULL DUPLEX with their existing PSK31 for receive 2) It makes your signal constant in the waterfall for You 3) and for everyone else even if they are not running anything special!
Maybe Andrew can comment on whether two separate sound cards are needed or if it is possible to use a single sound card?
Bob, WB4aPR
-----Original Message----- From: [email protected] Sent: Wednesday, July 15, 2015 6:41 PM To: [email protected] Subject: [amsat-bb] PSAT PSK31 experimental software
I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Software is installed and ready for the 04:04utc pass tonight. (21:05 PDT)
It appears to work testing to a loop back to the soundcard. I can watch the PSK31 signal change frequency on the receive . Remember two programs can share the sound card.
I have and hour to figure how to set up more macros.
BOB KO6TZ
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder%...
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder%...
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k%5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I made a successful contact with Dave W0DHB on the 19:35u pass of NO-84. It was hard copy, chock it up to band conditions I guess. There was a pulsing noise and fade, probably on the 10m up link.
BOB KO6TZ
Playing back the recording I agree with Bob there was pulsing and fading that can be seen with the recording .
Bob gets into the bird better than I do, I'm going to try 10m tuned 80m dipole next time.
I have refined the uplink offset it's close to -275 Hz . If your Uplink freq is 28.119725 your downlink center frequency should match your uplink center frequency.
The DopplerPSK program simplifies operating NO-84 greatly.
Thanks for putting this together Andy.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of KO6TZ Bob Sent: Thursday, July 16, 2015 2:17 PM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
I made a successful contact with Dave W0DHB on the 19:35u pass of NO-84. It was hard copy, chock it up to band conditions I guess. There was a pulsing noise and fade, probably on the 10m up link.
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
What is the station equipment, antennas etc. Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 2:57 PM, David W0DHB wrote:
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k%5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
hEDRE i FIXED THAT url ALSO,
Joe * Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 2:57 PM, David W0DHB wrote:
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k%5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Thanks Joe I forgot BB would wrap line. This one works also https://www.dropbox.com/s/r6ywkczcf95o3f2/NO84.wav?dl=0
Base equipment is 10m SSB Transmitter with the ability for TX audio being fed by Computer sound card. 70cm FM RX / antenna system capable of copying satellite downlink and able to feed RX audio to Computer. Computer with Windows/Mac , DopplerSQF software and software that will demod PSK31 (Fldigi,Digipan DM780 to name a few)
Software to do downlink doppler tuning is very useful, but not required.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Joe Sent: Thursday, July 16, 2015 4:24 PM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
hEDRE i FIXED THAT url ALSO,
Joe * Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 2:57 PM, David W0DHB wrote:
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k% 5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but
we'll see.
I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the
default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM
passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transp onder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the
official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Thats what I was most interested in the antennas. describe them...
Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 5:43 PM, David W0DHB wrote:
Thanks Joe I forgot BB would wrap line. This one works also https://www.dropbox.com/s/r6ywkczcf95o3f2/NO84.wav?dl=0
Base equipment is 10m SSB Transmitter with the ability for TX audio being fed by Computer sound card. 70cm FM RX / antenna system capable of copying satellite downlink and able to feed RX audio to Computer. Computer with Windows/Mac , DopplerSQF software and software that will demod PSK31 (Fldigi,Digipan DM780 to name a few)
Software to do downlink doppler tuning is very useful, but not required.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Joe Sent: Thursday, July 16, 2015 4:24 PM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
hEDRE i FIXED THAT url ALSO,
Joe
Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 2:57 PM, David W0DHB wrote:
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k% 5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but
we'll see.
I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the
default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM
passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transp onder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the
official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I'm using a GAP Challenger vertical for 10m and on 70cm an M2 30el (15h/15V) RHCP yagi on a Yaesu G5500 az/el rotator, but a handheld Arrow or similar antenna for 70cm would probably work fine.
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Joe Sent: Thursday, July 16, 2015 6:03 PM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Thats what I was most interested in the antennas. describe them...
Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 5:43 PM, David W0DHB wrote:
Thanks Joe I forgot BB would wrap line. This one works also https://www.dropbox.com/s/r6ywkczcf95o3f2/NO84.wav?dl=0
Base equipment is 10m SSB Transmitter with the ability for TX audio being fed by Computer sound card. 70cm FM RX / antenna system capable of copying satellite downlink and able to feed RX audio to Computer. Computer with Windows/Mac , DopplerSQF software and software that will demod PSK31 (Fldigi,Digipan DM780 to name a few)
Software to do downlink doppler tuning is very useful, but not required.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Joe Sent: Thursday, July 16, 2015 4:24 PM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
hEDRE i FIXED THAT url ALSO,
Joe
Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 7/16/2015 2:57 PM, David W0DHB wrote:
Andy
Here is a recording of the 1930 pass of NO-84 https://www.dropbox.com/s/2qtb5d2cm3ktrr0/FM%20435.359944MHz%20%5B12k % 5D%207 -16-2015%2019%2033%2052.wav?dl=0
Bob KO6TZ and I had a successful QSO. My audio was set at 1500 Uplink frequency of 28.119700 MHz .
The signals seemed to be stable, decoding at my end (DM780 ) was not stellar, I'm running the recording through fldigi, MixW and Digipan to see if it's any better.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of David W0DHB Sent: Thursday, July 16, 2015 8:41 AM To: '[email protected]'; [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Hey Andy
The ability to select soundcard would be helpful. In my setup TX audio is fed by a virtual audio cable set to match the 48K sample rate that DopplerPSK is using. Folks using windows should set the recording device side of their soundcard to a 48K sample rate (it usually defaults to 44.1K).
You are correct that the uplink frequency is high, I apply a -300 Hz calibration offset.
Thanks for all your work on this.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Thursday, July 16, 2015 6:29 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but
we'll see.
I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the
default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM
passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20trans p onder% 20WEB%20spec02.htm
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the
official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the
official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
This could make for a great AMSAT Journal article!
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone
On Jul 16, 2015, at 8:28 AM, "[email protected]" [email protected] wrote:
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder%...
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
And for OSCAR NEWS :)
73
Graham G3VZV
-----Original Message----- From: EMike McCardel Sent: Thursday, July 16, 2015 3:45 PM To: [email protected] Cc: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
This could make for a great AMSAT Journal article!
EMike
EMike McCardel, KC8YLD VP for Educational Relations AMSAT-NA
Sent from my iPhone
On Jul 16, 2015, at 8:28 AM, "[email protected]" [email protected] wrote:
Bob, Dave; That's great. I'm interested in how well it tracks when the satellite is at a very high elevation and the Doppler is >3 Hz/s. I suspect the error is going to be mostly in the estimates of the orbital elements, but we'll see. I will try to join you on the pass when I can cobble together an uplink and a downlink in the same place--probably next week sometime after I get back from vacation.
I think you should be able to share a sound device on most OS's, but I have not tried. I assumed it would work on modern Windows OS's because of the hardware abstraction. The program appears to run fine on OSX, but I have not tried running CocoaModem or some other software next to it. Ultimately I could also add a demodulator to the program itself, but that will take some work....I know several hams have separate sound cards for radio stuff, so I may need to add a device selection option in case the system default (or whatever Java picks as the default) isn't what you want.
The audio frequency displayed in DopplerPSK is the audio frequency being send to the radio, not what you should expect in the passband of your downlink receiver. The LO on PSAT is apparently a bit below 28120 KHz, so if your radio was tuned to 28120 USB (suppressed carrier frequency) you would expect to be a bit higher than 2000Hz in the FM passband:
http://www.urel.feec.vutbr.cz/esl/files/Projects/PSAT/P%20sat%20transponder%...
In general, if you want to be lower in the passband I would lower your transmitter RF frequency rather than the audio frequency going to the transmitter. The reason being that if you have any non-linearity in the audio chain you don't end up transmitting a harmonic higher in the band that might bother someone else. Of course, you can probably see if this is an issue or not since the satellite also serves as a crude signal analyzer :-) I chose 2000 Hz as a center since at maximum Doppler of around 700 Hz, the ~2700 Hz tone should go through the transmitter's IF filter without too much attenuation while keeping all the third harmonics and most of the time the second harmonic above the cutoff of a 3 KHz IF filter. Every radio is a bit different, however. You may find that the 1500Hz sweep in the program shows you all your passband ripple in your IF filter :-)
Since it works, I'm more motivated to improve the ergonomics of the interface. Much of that depends on the unique operating practices of satellite operation.
Andy K0SM/2
On Thursday, July 16, 2015 12:31 AM, KO6TZ Bob [email protected] wrote:
The software worked great !!! Produced a straight line on the waterfall for the down link.
As expected, I was alone on the pass, so no opportunity for a contact.
I was using digi-pan for the RX, my signal was at around 2200Hz.. Probably an indication the oscillator in my radio is off a bit. I think I will lower the frequency from 2000 to about 1600. That will put my signal lower in the VF pass band.
I like the program. Had good copy.
THANKS.....
BOB KO6TZ _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Tried it out and worked ok, I need to create macros also as well as shutoff my uplink Doppler tuning which was running during my test. Bob, let's try and QSO tomorrow 1929 .
I like not having to have 2 full psk programs running.
Dave W0DHB
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, July 15, 2015 4:41 PM To: [email protected] Subject: [amsat-bb] PSAT PSK31 experimental software
I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
PSAT seems to be returning to good health. We will keep the digipeater off, but will now announce it is safe to resume PSK31 experiments.
Remember, when we ran out of power, great progress had been made with Andy's pre-compensating PSK31 uplink software (below). Here also are the latest elements for PSAT:
PSAT 1 90720U 15234.36512451 +.00008395 +00000-0 +21488-3 0 0099 2 90720 054.9897 293.1329 0244566 052.6872 309.6216 15.1526532401420
When PSAT-1 is using the PSAT-1 callsign, that means the digipeater is off. But as of now, PSK31 experimentation is authorized. 28.120 PSK31 uplink and 435.350 FM downlink.
Bob, WB4aPR
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, July 15, 2015 6:41 PM To: [email protected] Subject: [amsat-bb] PSAT PSK31 experimental software
I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Just curious...why do we not refer to this sat as NO-84? Seems to me that consistency is the best way to go
73, ted K7TRK
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Robert Bruninga Sent: Monday, August 24, 2015 7:17 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
PSAT seems to be returning to good health. We will keep the digipeater off, but will now announce it is safe to resume PSK31 experiments.
Remember, when we ran out of power, great progress had been made with Andy's pre-compensating PSK31 uplink software (below). Here also are the latest elements for PSAT:
PSAT 1 90720U 15234.36512451 +.00008395 +00000-0 +21488-3 0 0099 2 90720 054.9897 293.1329 0244566 052.6872 309.6216 15.1526532401420
When PSAT-1 is using the PSAT-1 callsign, that means the digipeater is off. But as of now, PSK31 experimentation is authorized. 28.120 PSK31 uplink and 435.350 FM downlink.
Bob, WB4aPR
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, July 15, 2015 6:41 PM To: [email protected] Subject: [amsat-bb] PSAT PSK31 experimental software
I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I guess because I have been living with it night and day since 2007 and working on it over and over again for 8 years as PSAT. But you re right. I don't like the ambiguity. Ill try to say PSAT(NO44).
-----Original Message----- From: Ted [mailto:[email protected]] Sent: Monday, August 24, 2015 7:30 PM To: 'Robert Bruninga'; [email protected] Subject: RE: [amsat-bb] PSAT PSK31 experimental software
Just curious...why do we not refer to this sat as NO-84? Seems to me that consistency is the best way to go
73, ted K7TRK
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of Robert Bruninga Sent: Monday, August 24, 2015 7:17 AM To: [email protected] Subject: Re: [amsat-bb] PSAT PSK31 experimental software
PSAT seems to be returning to good health. We will keep the digipeater off, but will now announce it is safe to resume PSK31 experiments.
Remember, when we ran out of power, great progress had been made with Andy's pre-compensating PSK31 uplink software (below). Here also are the latest elements for PSAT:
PSAT 1 90720U 15234.36512451 +.00008395 +00000-0 +21488-3 0 0099 2 90720 054.9897 293.1329 0244566 052.6872 309.6216 15.1526532401420
When PSAT-1 is using the PSAT-1 callsign, that means the digipeater is off. But as of now, PSK31 experimentation is authorized. 28.120 PSK31 uplink and 435.350 FM downlink.
Bob, WB4aPR
-----Original Message----- From: AMSAT-BB [mailto:[email protected]] On Behalf Of [email protected] Sent: Wednesday, July 15, 2015 6:41 PM To: [email protected] Subject: [amsat-bb] PSAT PSK31 experimental software
I put together an experimental program called DopplerPSK to compensate for the Doppler shift on the NO-84 (or NO-83) PSK31 uplink. In essence, its a PSK31 transmitter that is merged with an orbital propagator to cause your transmitted signal to drift exactly opposite to uplink Doppler effect. It does this in a phase-continuous correction so that you don't get errors due to discontinuous frequency adjustments from controlling a radio in discrete steps. In the case of PSAT and BricSat, it should cause your signal to stay at constant frequency in the satellite's uplink receiver, and thus you should get a stable frequency on the FM downlink as well. In turn, this means you should be able to use your favorite PSK31 demodulating software to copy the downlink since the frequency drift should stay well within the AFC tolerance of the software. Anyway, if there are any adventurous people who are set up to give this a go, I would be interested in seeing if it actually works. You can find a rough quick-start guide (which contains an explanation of how it works and what you need to get started) and the application package on the rather minimalist page here: http://www.frontiernet.net/~aflowers/dopplerpsk/dopplerpsk.html It's an experiment, so be prepared for disappointment. I am :-) Andy K0SM/2 _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
participants (8)
-
aflowers＠frontiernet.net -
David W0DHB -
EMike McCardel -
Graham Shirville -
Joe -
KO6TZ Bob -
Robert Bruninga -
Ted