I have made 2 contacts now both were VO-52. Both times on SSB and very confusing. So say I'm working you. I found a clear freq by sending alot dots. The uplink tx is switched to LSB. Do I leave the tuning dial on the uplink rig and just use the tuning dial on the downlink to do my tuning? Or do I juggle both rigs tuning dial and get confused?
Jerry - NR5A - South Dakota www.freewebs.com/nr5a http://groups.yahoo.com/group/Minimalist_QRP_Transceivers/ http://www.cakewalkblogs.com/nr5asminimalradio/index.aspx http://nr5abeaconblog.blogspot.com/
If you are not controlling both with a computer, then try to just tune the higher of the two frequencies, which is the uplink on VO-52. Only tune the receive when you have to in order to copy the other station.
Take a look at http://www.amsat.org/amsat/features/one_true_rule.html
73, Drew KO4MA
----- Original Message ----- From: "Jerry Felts" [email protected] To: [email protected] Sent: Saturday, April 18, 2009 2:07 PM Subject: [amsat-bb] Tuning
I have made 2 contacts now both were VO-52. Both times on SSB and very confusing. So say I'm working you. I found a clear freq by sending alot dots. The uplink tx is switched to LSB. Do I leave the tuning dial on the uplink rig and just use the tuning dial on the downlink to do my tuning? Or do I juggle both rigs tuning dial and get confused?
Jerry - NR5A - South Dakota www.freewebs.com/nr5a http://groups.yahoo.com/group/Minimalist_QRP_Transceivers/ http://www.cakewalkblogs.com/nr5asminimalradio/index.aspx http://nr5abeaconblog.blogspot.com/ _______________________________________________ Sent via [email protected]. 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
Before the advent of computer Doppler tuning compensation, the convention was to tune the radio on the highest band as that is where the doppler is the largest and to leave the other one alone as much as possible. That is not a perfect solution as different stations in the footprint see different Doppler shifts and it is usually unavoidable to tweak both radios. But you can generally save yourself a lot of confusion by only tuning one radio, the highest one, whether it be receive or transmit.
If you are using a computer for tracking, it should also give you the doppler correction even if you are not controlling the radios with it and you should find your downlink without too much trouble. It is confusing at first, but after a while you get hte hang of it and it becomes second nature.
If you can catch AO-7 in Mode A, that is a good mode to practice Doppler compensation with as the doppler shifts are much lower. - Duffey
On Apr 18, 2009, at 12:07 PM, Jerry Felts wrote:
I have made 2 contacts now both were VO-52. Both times on SSB and very confusing. So say I'm working you. I found a clear freq by sending alot dots. The uplink tx is switched to LSB. Do I leave the tuning dial on the uplink rig and just use the tuning dial on the downlink to do my tuning? Or do I juggle both rigs tuning dial and get confused?
Jerry - NR5A - South Dakota www.freewebs.com/nr5a http://groups.yahoo.com/group/Minimalist_QRP_Transceivers/ http://www.cakewalkblogs.com/nr5asminimalradio/index.aspx http://nr5abeaconblog.blogspot.com/ _______________________________________________ Sent via [email protected]. 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
-- KK6MC James Duffey Cedar Crest NM
For the linear transponder Satellites I have found with my IC 820H using the main tuning dial to adjust receive and switching that side and adjust for transmit works the best during Field Day operations. The I-Com is just to clumsy to use the sub receiver, RIT does not have enough range, no easy way to adjust the offset, transmit power, ETC. I calculate the offset VS time using Instant Track in advance and work off of paper data. I set the elevation of the mast to match the pass and a single rotator performs both elevation and azimuth functions.
If we had a HEO I would consider buying something better than the 820, but for now I drag out the old 820 and make a few contacts for W6NWG each year at FD, and that is the extent of my satellite activity.
Art, KC6UQH
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Duffey Sent: Saturday, April 18, 2009 7:18 PM To: Jerry Felts Cc: Amsat BB Subject: [amsat-bb] Re: Tuning
Before the advent of computer Doppler tuning compensation, the convention was to tune the radio on the highest band as that is where the doppler is the largest and to leave the other one alone as much as possible. That is not a perfect solution as different stations in the footprint see different Doppler shifts and it is usually unavoidable to tweak both radios. But you can generally save yourself a lot of confusion by only tuning one radio, the highest one, whether it be receive or transmit.
If you are using a computer for tracking, it should also give you the doppler correction even if you are not controlling the radios with it and you should find your downlink without too much trouble. It is confusing at first, but after a while you get hte hang of it and it becomes second nature.
If you can catch AO-7 in Mode A, that is a good mode to practice Doppler compensation with as the doppler shifts are much lower. - Duffey
On Apr 18, 2009, at 12:07 PM, Jerry Felts wrote:
I have made 2 contacts now both were VO-52. Both times on SSB and very confusing. So say I'm working you. I found a clear freq by sending alot dots. The uplink tx is switched to LSB. Do I leave the tuning dial on the uplink rig and just use the tuning dial on the downlink to do my tuning? Or do I juggle both rigs tuning dial and get confused?
Jerry - NR5A - South Dakota www.freewebs.com/nr5a http://groups.yahoo.com/group/Minimalist_QRP_Transceivers/ http://www.cakewalkblogs.com/nr5asminimalradio/index.aspx http://nr5abeaconblog.blogspot.com/ _______________________________________________ Sent via [email protected]. 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
-- KK6MC James Duffey Cedar Crest NM
_______________________________________________ Sent via [email protected]. 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
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Back in the "goode olde dayes", when OSCAR VI and OSCAR VII were the only 2 satellites available, the general consensus was not to try to compensate for Doppler by moving the transmit frequency. Since everyone knew that Doppler would affect the downlink frequency we just kept a hand on the receiver and manually compensated for the Doppler shift. Trying to compensate for the Doppler by changing the transmit frequency only complicated things even more.
Also, having a fixed elevation of around 30 degrees on the antenna generally took care of the need for an elevation rotor. Yes, if you had an elevation rotor you could often extend the coverage by between 10 and 20 percent. But, for those who did not have an elevation rotor fixing the antennas at around 30 degrees above the horizontal worked pretty darn well.
Glen, K9STH AMSAT 239/LM 463
Website: http://k9sth.com
--- On Sat, 4/18/09, Art McBride [email protected] wrote:
For the linear transponder Satellites I have found with my IC 820H using the main tuning dial to adjust receive and switching that side and adjust for transmit works the best during Field Day operations. The I-Com is just to clumsy to use the sub receiver, RIT does not have enough range, no easy way to adjust the offset, transmit power, ETC. I calculate the offset VS time using Instant Track in advance and work off of paper data. I set the elevation of the mast to match the pass and a single rotator performs both elevation and azimuth functions.
participants (5)
-
Andrew Glasbrenner -
Art McBride -
Glen Zook -
James Duffey -
Jerry Felts