Hi Satelliters, Might cause some flames with this but here goes: With a good few years of operating on the SSB sats, AO's-10,13,40, RS10, FO-20,FO-29 and 98 countries confirmed I can agree totally with the "one true rule" in theory. When stations at each end of the QSO use the method it works flawlessly, I have done it with QSO partners using Fod track and with Instantrak computer Doppler correction, but there is the problem. Many of the stations that you want to work will be using manual tuning methods, so as you maintain your frequencies at the satellite, according to the rule, your QSO partner will have to search for you. Then when its your turn to transmit he will have to search for you.
The practical solution that I and I believe most of the ops. I have worked seem to use is to have short overs and to adjust frequencies the TX to try and keep the QSO in a fixed spot on the receiver. Following the other "often recommended" method of adjusting the higher frequency irrespective of its function, up link or down link, cause QSO's to drift across the pass band causing problems for other users. The other point worth making for newcomers to the SSB birds is to start on the easy passes/satellites first to get the knack of manual tuning. For example, try VO-52 with its 2m downlink, and to pick low elevation passes where the rate of change of frequency due to Doppler shift is less. Don't expect to get it right with near overhead passes of FO-29 until you have delevop your skills. We were all beginners once so don't be afraid to have a go and make a few mistakes. I am pleased to say that in my experience the SSB satellites have a great user community who maintain high operating standard and welcome new ops. Have fun on the birds 73 John G7HIA Lamenting the loss of our lovely HEO birds, Happy Days !!
A rookie observation….
That article was written in 1994 —well prior to the state of the art in full doppler correction. I use MacDoppler for adjusting the VFOs and it happily adjusts both of them. The ONLY time I run into a problem where the received station is moving is when it is clear someone is NOT using full doppler correction.
I would humbly submit that this being 2011 and both SatPC32 and MacDoppler handle full doppler correction, the exception should be the One Tune Rule and the norm should be full doppler correction. I know that when I work someone that is also using full doppler correction, it is a joy as the radio just happily stays tuned and we move during the whole pass.
Is the state of the art still such that we are all using radios that do not support full doppler correction?
I will put my flame suit on now…
73,
Tom
Tom Schaefer, NY4I [email protected] EL88pb Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15
On Jun 9, 2011, at 6:23 AM, John Heath wrote:
Hi Satelliters,
Might cause some flames with this but here goes:
With a good few years of operating on the SSB sats, AO's-10,13,40, RS10, FO-20,FO-29 and 98 countries confirmed I can agree totally with the "one true rule" in theory. When stations at each end of the QSO use the method it works flawlessly, I have done it with QSO partners using Fod track and with Instantrak computer Doppler correction, but there is the problem.
Many of the stations that you want to work will be using manual tuning methods, so as you maintain your frequencies at the satellite, according to the rule, your QSO partner will have to search for you. Then when its your turn to transmit he will have to search for you.
The practical solution that I and I believe most of the ops. I have worked seem to use is to have short overs and to adjust frequencies the TX to try and keep the QSO in a fixed spot on the receiver.
Following the other "often recommended" method of adjusting the higher frequency irrespective of its function, up link or down link, cause QSO's to drift across the pass band causing problems for other users.
The other point worth making for newcomers to the SSB birds is to start on the easy passes/satellites first to get the knack of manual tuning. For example, try VO-52 with its 2m downlink, and to pick low elevation passes where the rate of change of frequency due to Doppler shift is less. Don't expect to get it right with near overhead passes of FO-29 until you have delevop your skills.
We were all beginners once so don't be afraid to have a go and make a few mistakes. I am pleased to say that in my experience the SSB satellites have a great user community who maintain high operating standard and welcome new ops.
Have fun on the birds
73 John G7HIA
Lamenting the loss of our lovely HEO birds, Happy Days !! _______________________________________________ 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
It's certainly the case that many people operate "out in the field" and do not have a computer available. My radios are not computer controlled, even in the shack.
On 09-Jun-11 11:08, Tom Schaefer, NY4I wrote:
Is the state of the art still such that we are all using radios that do not support full doppler correction?
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.
Growing up on the birds when you had to twist the BIG knob to keep everyone on freq is not not a big deal. And to this day i still don't know why it seems to be a problem now days.
It all just takes practice. just like in field day coming up our club tries to get the non HF users to come out and try it. and at times it's incredibly painful to watch the guy that operates "Channelized" radios.
IE: 2 meter FM
How it will take them minutes to finally be within 500Hz of being on freq of a ssb signal. And even then most of the time they will be calling someone when it's obvious they are no where near on freq. then it's twiddling the big knob again going right past on freq spot and again try again off freq. Where a seasoned operator will tune them in in 1/2 a sec coming in from one side and stop dead on freq.
it all just takes time on the air.
simple.
Joe WB9SBD
The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com
On 6/9/2011 7:18 AM, Nigel Gunn G8IFF/W8IFF wrote:
It's certainly the case that many people operate "out in the field" and do not have a computer available. My radios are not computer controlled, even in the shack.
On 09-Jun-11 11:08, Tom Schaefer, NY4I wrote:
Is the state of the art still such that we are all using radios that do not support full doppler correction?
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
OK my brain may be playing tricks, but if you vary only your transmit frequency such that you always hear yourself on the same downlink frequency, isn't it true that the other station may not necessarily be hearing you on the same downlink frequency and is chasing you anyway? Your doppler is +5kHz (for example) on the receive, the bird is just about to pass overhead of me though so my receive ferquency goes rapidly from +2kHz to -5kHz, your transmit tuning has no relation at all to what frequency I am listening on. Then the bird goes past you and you suddenly switch down 5kHz, so I have to follow you on my receive.
Or am I nuts? (Quite possible, come see where I work and you will understand!)
Jerry NØJY
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.
doppler effects both paths, up and down.
so at least if everyone is listening to a 100Hz freq tone at 100 Hz, we are all on the same freq.
Joe WB9SBD
The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com
On 6/9/2011 9:35 AM, [email protected] wrote:
OK my brain may be playing tricks, but if you vary only your transmit frequency such that you always hear yourself on the same downlink frequency, isn't it true that the other station may not necessarily be hearing you on the same downlink frequency and is chasing you anyway? Your doppler is +5kHz (for example) on the receive, the bird is just about to pass overhead of me though so my receive ferquency goes rapidly from +2kHz to -5kHz, your transmit tuning has no relation at all to what frequency I am listening on. Then the bird goes past you and you suddenly switch down 5kHz, so I have to follow you on my receive.
Or am I nuts? (Quite possible, come see where I work and you will understand!)
Jerry NØJY
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.
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
Jerry's correct. If you only adjust your transmit frequency, such that your receive frequency appears to stay the same -- then you're automatically correcting for your own downlink doppler, but not for anyone elses. Other hams in the footprint will still have to chase you. The only way to stick with the "one true rule" is to adjust *both* uplink and downlink during the pass.
That being said, adjusting the higher (UHF) transmit frequency on VO-52 and AO-07 only (ie. manual control) will get you pretty close, and you won't drift a whole lot. I hear plenty of hams doing this, as long as there are just one or a two QSO's going on, they don't drift into each other very often.
73 de Dave KB5WIA / CM88 SatPC32 with 2xFT817ND
On Thu, Jun 9, 2011 at 7:35 AM, [email protected] wrote:
OK my brain may be playing tricks, but if you vary only your transmit frequency such that you always hear yourself on the same downlink frequency, isn't it true that the other station may not necessarily be hearing you on the same downlink frequency and is chasing you anyway? Your doppler is +5kHz (for example) on the receive, the bird is just about to pass overhead of me though so my receive ferquency goes rapidly from +2kHz to -5kHz, your transmit tuning has no relation at all to what frequency I am listening on. Then the bird goes past you and you suddenly switch down 5kHz, so I have to follow you on my receive.
Or am I nuts? (Quite possible, come see where I work and you will understand!)
Jerry NØJY
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.
Hi!
That being said, adjusting the higher (UHF) transmit frequency on VO-52 and AO-07 only (ie. manual control) will get you pretty close, and you won't drift a whole lot. I hear plenty of hams doing this, as long as there are just one or a two QSO's going on, they don't drift into each other very often.
Actually, if stations would spread out a bit more on the transponders, this would be even less of an issue. There is so much space that goes to waste on these transponders, when everyone seems to never go more than a few kHz up or down from the center. Sometimes, everyone appears to be jammed up around the center separated by 1 or 1.5 kHz between signals. When we have transponders with 50 to 100 kHz to play with depending on the satellite, that seems crazy. At least there's room where someone can go far away from the center to do testing and not bother those around the center.
I'm one of those who does not use computer control, operating portable stations in the field. I try to follow the portion of the One True Rule about making adjustments on the higher of the two frequencies when not using full computer control. Sometimes I have to make adjustments on both frequencies to keep up with those who are fully computer controlled. I use an FT-817ND as my transmitter, and either a second FT-817ND or a Kenwood TH-F6A HT for my receiver (that HT has an all-mode wide- band receiver in it). Whenever I get a home station again, or find a laptop/netbook with an LCD panel that I can see well in the field, I will take another look at putting my 817s under the control of SatPC32.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
At 01:01 PM 6/9/2011, you wrote:
Actually, if stations would spread out a bit more on the transponders, this would be even less of an issue. There is so much space that goes to waste on these transponders, when everyone seems to never go more than a few kHz up or down from the center.
True.
I'm a very big on computer control. It seems that once you find a "free" spot it's yours. That is till someone chasing someone else crosses your QSO.
I really fail to see how someone with a pair of H/T's tuning and tuning and tuning can call that fun.
I'll stick with my FT847 and computer control.
John, W0JAB
Hi John!
I'm a very big on computer control. It seems that once you find a "free" spot it's yours. That is till someone chasing someone else crosses your QSO.
This is where spreading out would come in handy. This seems to be more of an issue on FO-29, where the general convention is to adjust the 70cm downlink - by letting it drift down - while keeping the 2m uplink fixed. I see this as less of an issue on AO-7 or VO-52, where adjustments are generally made on the uplink if someone isn't running full computer control. For AO-7 and VO-52, it would still help if stations would spread out a little more and made use of more of the space on those transponders.
I really fail to see how someone with a pair of H/T's tuning and tuning and tuning can call that fun.
I wish my 817s were HT-sized. I could easily shrink the size of the bag I carried my gear in to and from Australia if they were that small, for example if I had radio sized like the TH-F6A I have. :-)
My old laptop bag that could handle laptops with 17" LCD displays has been perfect for carrying my 817s, TH-F6A, and all sorts of other items I use for portable satellite operating. The two 817s would go in the space where a laptop would go, and then there's lots of other pockets and areas for the rest of the stuff. Even space to jam some non-radio stuff, to avoid overweight charges for my checked bags.
There really isn't so much of the "tuning and tuning and tuning" you describe when working SSB via satellite. Yes, minor adjustments are done with every over during a QSO or when making repeated CQ calls, but that's nothing compared to chasing the S-band downlink when AO-51 had it on in the past. Now that was "tuning and tuning and tuning" throughout a pass.
I'll stick with my FT847 and computer control.
I have thought about trying computer control at length for my situation operating portable, and have chosen not to go in that direction. In any event, I prefer getting on the satellites with the gear I have and manually adjusting the radios over not getting on those satellites at all. I also have the same station available away from home - sometimes very far from home - as I would use here in Phoenix.
And, yes - even with the manual tuning I have to do for working SSB and CW via satellite, it is fun!
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
This is a great thread.
Well, I am going to continue with full doppler and just resolve myself to tuning in some people that are not quite there yet. As a lot, I would think adding computer control to handle full doppler would not be that big a deal nowadays as most of the programs support it. I am not telling you how to spend your money though. The big test will be at Field Day when I am using full doppler and listening to everyone do the doppler-shuffle. :)
See you on the air as W4TA from Field Day but NEVER on an FM bird.
73,
Tom Schaefer, NY4I [email protected] EL88pb Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15
On Jun 9, 2011, at 1:19 PM, David Palmer KB5WIA wrote:
Jerry's correct. If you only adjust your transmit frequency, such that your receive frequency appears to stay the same -- then you're automatically correcting for your own downlink doppler, but not for anyone elses. Other hams in the footprint will still have to chase you. The only way to stick with the "one true rule" is to adjust *both* uplink and downlink during the pass.
That being said, adjusting the higher (UHF) transmit frequency on VO-52 and AO-07 only (ie. manual control) will get you pretty close, and you won't drift a whole lot. I hear plenty of hams doing this, as long as there are just one or a two QSO's going on, they don't drift into each other very often.
73 de Dave KB5WIA / CM88 SatPC32 with 2xFT817ND
On Thu, Jun 9, 2011 at 7:35 AM, [email protected] wrote:
OK my brain may be playing tricks, but if you vary only your transmit frequency such that you always hear yourself on the same downlink frequency, isn't it true that the other station may not necessarily be hearing you on the same downlink frequency and is chasing you anyway? Your doppler is +5kHz (for example) on the receive, the bird is just about to pass overhead of me though so my receive ferquency goes rapidly from +2kHz to -5kHz, your transmit tuning has no relation at all to what frequency I am listening on. Then the bird goes past you and you suddenly switch down 5kHz, so I have to follow you on my receive.
Or am I nuts? (Quite possible, come see where I work and you will understand!)
Jerry NØJY
I always varied the transmit.
This way the person I'm talking to as well as any other listeners are all on the same freq listening.
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
At 04:06 AM 6/10/2011, Tom Schaefer, NY4I wrote:
This is a great thread.
Well, I am going to continue with full doppler and just resolve myself to tuning in some people that are not quite there yet. As a lot, I would think adding computer control to handle full doppler would not be that big a deal nowadays as most of the programs support it. I am not telling you how to spend your money though. The big test will be at Field Day when I am using full doppler and listening to everyone do the doppler-shuffle. :)
When I get my antennas sorted, I'm in the computer controlled camp (which was helpful for testing). I may be able to solve a few issues by taking the Macbook into the field and using it to provide Doppler correction for a mobile/portable station. Computer control will save me a couple of arms adjusting VFOs, so I'll be free to point the antenna at the right patch of sky. :)
73 de VK3JED / VK3IRL http://vkradio.com
participants (9)
-
David Palmer KB5WIA -
Joe -
John Becker -
John Heath -
n0jy＠lavabit.com -
Nigel Gunn G8IFF/W8IFF -
Patrick STODDARD (WD9EWK/VA7EWK) -
Tom Schaefer, NY4I -
Tony Langdon