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CX2SA > SATDIG 01.06.10 20:08l 705 Lines 23278 Bytes #999 (0) @ WW
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Today's Topics:
1. AMSAT Awards (Bruce)
2. Re: Doppler Tuning Convention Question (summary) (John Belstner)
3. Re: Doppler Tuning Convention Question (Luc Leblanc)
4. Organization Announcement- AMSAT INDIA (Nitin Muttin)
5. Doppler Discussion (Clint Bradford)
6. Re: AMSAT Awards (Tim - N3TL)
7. Re: Doppler Tuning Convention Question (summary) (Alan P. Biddle)
8. Re: Doppler Tuning Convention Question (Edward R Cole)
9. Re: Doppler Discussion (Tim - N3TL)
----------------------------------------------------------------------
Message: 1
Date: Tue, 01 Jun 2010 10:32:43 -0500
From: Bruce <kk5do@xxxxx.xxx>
Subject: [amsat-bb] AMSAT Awards
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Message-ID: <4C05281B.3010605@xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
The following have entered into the Satellite Communicators Club for
making their first satellite QSO.
Brennan Price, N4QX
John Neeley, W6ZKH
Ed Empey, WA7ETH
Jennifer Melfi, KC2TMA
The following have earned the AMSAT Communications Achievement Award.
Larry Teran, KI6YAA, #512
John Neeley, W6KZH, #513
Gerry Krebs, N0JE, #514
Hugh Empey, W7ETH, #515
The following have earned the W4AMI Achievement Award (for 1000 contacts)
Evangelos Kafetzopoulos, SV1EEK, endorsement from 3000 to 4000
The following have earned the W4AMI Achievement Award for 5000 contacts
Evangelos Kafetzopoulos, SV1EEK, #23
The following have earned the South Africa AMSAT Communications
Achievement Award
Larry Teran, KI6YAA, #US145
Gerry Krebs, N0JE, #US146
Hugh Empey, WA7ETH, #US147
To see all the awards visit http://www.amsat.org or
http://www.amsatnet.com
Bruce Paige, KK5DO
AMSAT Director Contests and Awards
ARRL Awards Manager (WAS, 5BWAS, VUCC), VE
Houston AMSAT Net - Wed 0100z on Echolink - Conference *AMSAT*
Also streaming MP3 at http://www.amsatnet.com
Podcast at http://www.amsatnet.com/podcast.xml or iTunes
------------------------------
Message: 2
Date: Tue, 1 Jun 2010 09:14:05 -0700
From: John Belstner <jbelstner@xxxxx.xxx>
Subject: [amsat-bb] Re: Doppler Tuning Convention Question (summary)
To: amsat-bb@xxxxx.xxx
Message-ID: <4B7D8000-50F3-4CD3-931A-0183091CCCC1@xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Thanks to everyone that responded.
For those that have been on the list for years this thread may be a dull
rerun, but as a newbie, the information is useful.
>From everyones responses, it appears that indeed there are currently two
conventions:
1. Full Doppler CAT tuning
2. Manually tuning the higher frequency while keeping the lower fixed
I know that operators have been successfully using convention #2 for years
so this is my lack of sat operating experience talking here, but just
looking at the math it seems that it would be difficult for two stations
with different velocity vectors to the satellite to communicate without at
least one of them adjusting both TX and RX. I need to try this for myself I
guess.
One thing I did notice is that when operating Full Doppler CAT tuning I was
only able to successfully track other operators who were doing the same.
Cheers,
73, John W9EN
DM13le
W9EN@xxxxx.xxx
------------------------------
Message: 3
Date: Tue, 01 Jun 2010 03:32:22 -0400
From: Luc Leblanc <lucleblanc6@xxxxxxxxx.xx>
Subject: [amsat-bb] Re: Doppler Tuning Convention Question
To: amsat-bb@xxxxx.xxx
Cc: eu-amsat@xxxxxxxxxxx.xxx
Message-ID: <4C047F46.18273.431B63D@xxxxxxxxxxx.xxxxxxxxx.xx>
Content-Type: text/plain; charset=US-ASCII
This thread is cyclic but it is ok to be revisited time to time.
excerpt:
> My suggestion is to use full tuning until you find that the other operator
> isn't. Then adapt, usually by turning off the updating for the lower
> frequency. It isn't worth getting doctrinaire about it. However, by using
> the One True Rule as the default, you set a good example and encourage the
> movement of other operators in this direction. As you will find, it is
> truly painful to do it the manual way after getting used to automagic
> tuning. As we move above 70 cms, full tuning truly becomes necessary.
>
> Alan
> WA4SCA
>
excerpt:
> Tim,
>
> Speak for yourself :-) In the 20+ years I have been a satellite
> operator, I have never gotten computer doppler control to work right on the
> linear birds. It works great on FM, but I always wind up fighting it on the
> linear birds. As soon as I tune the other guy in the computer moves me off
> frequency. It's so much easier to just listen and adjust on the fly.
>
>
> 73,
> Joe kk0sd
excerpt:
> And since we're on the topic ... has anyone else noticed that the latest
> edition of "The ARRL Satellite Handbook" uses VO-52 as the example for
> Doppler tuning - and that it suggests that newcomers who are manually tuning
> for Doppler park their transmit frequency on the UHF uplink and tune the VHF
> downlink (i.e., the exact opposite of the One True Rule)? That is really
> mystifying and disappointing.
>
>
> 73 to all,
>
> Tim - N3TL
>
The one "true rule" is fine when your "Highest" frequency is your downlink
frequency "The frequency you adjust at your transceiver"
and the ARRL satellite handbook is giving the correct way with AO-52 i will
try to explain it below for the linear satellite.
Those who are fully auto doppler controlled always correct their uplink and
downlink frequency to be at the same spot on the satellite to
maintain the same audio pitch. Under normal standard work we should all
adjust the audio for "normal voice" but some prefer high pitch
voice and some low pitch voice. Auto doppler correction can be set to
maintain your audio pitch preference but if the other station adjust
his station for a low pitch it can be annoying for some operator who prefer
high pitch voice (Ore vice versa) but it can be corrected just
in cheating your RX base frequency a bit.
The main issue:
If you enter in a QSO with a fully doppler corrected station and you follow
the "One true rule" it is fine but not if this highest
frequency is your TX frequency. When you adjust your uplink (TX) frequency
you will change the normal frequency the receiving station PC
doppler tracking program is expecting. Those with full auto doppler
correction should disable their RX auto correction and they will have
to manually adjust their downlink frequency when an another station is not
auto correcting or manually correcting his uplink frequency.
The biggest impact when you don't adjust or that you manually adjust your
uplink frequency is that you can drift over another QSO. The ARRL
Handbook is correct when they give the VO-52 example but they should give
the explanation and this explanation is not easy to understand
for a new satellite user.
In an ideal satellite world all the users should use auto doppler
correction. In a less than ideal satellite world all the user should use
uplink auto doppler correction and in the actual real time satellitte world
be prepared for the worse... and be flexible...
There is also another chapter on the auto doppler correction when you will
try to answer a CQ call but depending of your type of
transceiver and type of doppler correctrion software you will have to
experience your own ways just take my station as an example.
My FT-847 in CAT mode does not send any data back to the PC (First version
of the FT-847) the transceiver can only received data from the
PC and if i want to answer a CQ call i have to reenter the new uplink and
downlink frequency of the calling station and try to tweaked them
during the QSO it is a lot of work on a 10 minutes pass...
There is a lot a flavour in the doppler correction world but IMHO the uplink
frequency should always be auto corrected and if it is not
auto corrected the TX frequency should never be adjusted only if you drift
on another QSO or if someone else is drifting on you. There no
perfect solution aside of the full auto doppler correction.
I'm using full auto doppler correction when transponder activity is low as
i always ended up stepping over a lot of station and be stepped
on when there is a lot of traffic on a transponder. The worse case i saw was
on AO-40 one fellow who was in full doppler correction ask the
other station to move away as he move over the other QSO'S telling he's
having priority over the manual corrected stations...
A suggestion is it possible to have a section on a transponder devoted only
for those who are using auto tracking in voice mode? lets say
the upper end section?
There is nothing perfect only imperfect solutions.
"-"
Luc Leblanc VE2DWE
Skype VE2DWE
www.qsl.net/ve2dwe
DSTAR urcall VE2DWE
WAC BASIC CW PHONE SATELLITE
------------------------------
Message: 4
Date: Tue, 1 Jun 2010 21:10:02 +0530 (IST)
From: Nitin Muttin <vu3tyg@xxxxx.xx.xx>
Subject: [amsat-bb] Organization Announcement- AMSAT INDIA
To: AMSAT-BB@xxxxx.xxx
Message-ID: <53186.92876.qm@xxxxxxx.xxxx.xx.xxxxx.xxx>
Content-Type: text/plain; charset=utf-8
May 31st 2010
Organization update for post of President and Vice President.
An emergency committe meeting was held on May 26th 2010 at the residence of
VU2RMS, Ramesh as we had recieved request from the current president Air
commodore Suby, VU2UV to relieve him from the post of the president citing
health reasons. This was accepted by the committe and was proposed and
accepted by the committe that VU2RMS, Ramesh take up the role of the
president and lead the organization towards the vision and mission of AMSAT
India.
It was also proposed by VU2POP, POP to request VU2VP, Dr. Ved Prakash
Sandlas to take up the role of Vice President which was accepted by the
committe and also by Dr Ved Prakash Sandlas when contacted by phone. VU2VP
is an active Radio Ham and associated with the Indian Amateur Radio
satellite programme from 1980's and an AMSAT India member.Detailed bio data
and his achievements and contributions can be found at
http://www.freewebs.com/vpsandlas/
Please join me in welcoming VU2RMS, Ramesh as the President and VU2VP,
Dr.Ved Prakash Sandlas as the Vice president of AMSAT India and we would like
to thank VU2UV, Air commodore Suby for his guidance and focus on the
activities during his tenure, he will continue to be a member of the core
committe.
Regards
Nitin [VU3TYG]
Secretary, AMSAT India
www.amsatindia.org
vu3tyg@xxxxxxxxxx.xxx
________________________________________________
------------------------------
Message: 5
Date: Tue, 1 Jun 2010 09:49:35 -0700
From: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>
Subject: [amsat-bb] Doppler Discussion
To: amsat-bb@xxxxx.xxx
Message-ID: <A8D93C31-AD08-48BE-9F42-DE732BDDD252@xxxxxxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
>> ... Doppler always will have a more pronounced effect (in relative terms,
of course, based on the frequencies being used) on the higher of the two ...
Here's the actual equation for determining Doppler shift ...
http://tinyurl.com/calc-dopp
Your generalization is correct. On a 45 degree pass of a sat that's in a
circular orbit at 497 miles up, approximate Doppler shifts calculate to ...
At 15m, +/- 477 Hz
At 10m, +/- 659 Hz
At 2m, +/- 3.27 kHz
At 70cm, +/- 9.76 kHz
At 23cm, +/- 28.5 kHz
at 13cm, +/- 53.8 kHz
Clint, K6LCS
http://www.work-sat.com
------------------------------
Message: 6
Date: Tue, 1 Jun 2010 11:24:30 -0700 (PDT)
From: Tim - N3TL <n3tl@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: AMSAT Awards
To: kk5do@xxxxx.xxxx kk5do@xxxx.xxxx "amsat-bb@xxxxx.xxxx
<amsat-bb@xxxxx.xxx>
Message-ID: <40237.87655.qm@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Congratulations to everyone. Well done!
73,
Tim - N3TL
________________________________
From: Bruce <kk5do@xxxxx.xxx>
To: "amsat-bb@xxxxx.xxxx <amsat-bb@xxxxx.xxx>
Sent: Tue, June 1, 2010 11:32:43 AM
Subject: [amsat-bb] AMSAT Awards
The following have entered into the Satellite Communicators Club for
making their first satellite QSO.
Brennan Price, N4QX
John Neeley, W6ZKH
Ed Empey, WA7ETH
Jennifer Melfi, KC2TMA
The following have earned the AMSAT Communications Achievement Award.
Larry Teran, KI6YAA, #512
John Neeley, W6KZH, #513
Gerry Krebs, N0JE, #514
Hugh Empey, W7ETH, #515
The following have earned the W4AMI Achievement Award (for 1000 contacts)
Evangelos Kafetzopoulos, SV1EEK, endorsement from 3000 to 4000
The following have earned the W4AMI Achievement Award for 5000 contacts
Evangelos Kafetzopoulos, SV1EEK, #23
The following have earned the South Africa AMSAT Communications
Achievement Award
Larry Teran, KI6YAA, #US145
Gerry Krebs, N0JE, #US146
Hugh Empey, WA7ETH, #US147
To see all the awards visit http://www.amsat.org or
http://www.amsatnet.com
Bruce Paige, KK5DO
AMSAT Director Contests and Awards
ARRL Awards Manager (WAS, 5BWAS, VUCC), VE
Houston AMSAT Net - Wed 0100z on Echolink - Conference *AMSAT*
Also streaming MP3 at http://www.amsatnet.com
Podcast at http://www.amsatnet.com/podcast.xml or iTunes
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. 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
------------------------------
Message: 7
Date: Tue, 1 Jun 2010 13:45:35 -0500
From: "Alan P. Biddle" <APBIDDLE@xxxxxx.xxx>
Subject: [amsat-bb] Re: Doppler Tuning Convention Question (summary)
To: "'John Belstner'" <jbelstner@xxxxx.xxx>, <amsat-bb@xxxxx.xxx>
Message-ID: <389211B011AD42CBAA1B621FA43D9146@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
John,
I meant to mention a nice page discussing Doppler shift. It explains many
of the questions/comments/rants brought up about Doppler shifts and
corrections:
http://www.qsl.net/vk3jed/doppler.html
It gives a few graphic illustrations of how Doppler shift varies depending
on the pass, and why it can be radically different for different stations in
the QSO. As you observed, Full Doppler Tuning, FDT, works for everybody,
everytime. I will add that any can play. Anything else is just an
approximation. We have 40 years of experience showing that approximation is
usuable, but we have long been able to do better.
Thanks for motivating me to get back to an article on exactly this subject I
have been meaning to finish.
73s,
Alan
WA4SCA
------------------------------
Message: 8
Date: Tue, 01 Jun 2010 10:58:00 -0800
From: Edward R Cole <kl7uw@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Doppler Tuning Convention Question
To: amsat-bb@xxxxx.xxx
Message-ID: <201006011858.o51Iw1AS000682@xxxxxx.xxxxxxxxx.xxx>
Content-Type: text/plain; charset="iso-8859-1"; format=flowed
Just a quick comment on Doppler effects. Doppler
offset from the resting frequency is observable
only on the radial velocity component of the
satellite and that is usually most significant at
AOS or LOS. BUT what the operator is usually
responding is to the rate of change of Doppler
and not the absolute value of the frequency
offset. Doppler rate change may occur more at mid-pass than elsewhere.
Regarding the "one true rule" that is generally
only accomplished by software tuning both uplink
and downlink simultaneously, the manual method of
tuning the higher frequency will never mesh
exactly with the other mode. FM should be more
forgiving of Doppler shifts due to the 15-KHz
bandwidth of the signal. Some radios even have
AFC to maintain change in frequency in the FM mode.
Higher frequencies show more Doppler and the rate
of change will also be proportional. Thus the
difficulty manual tuning mode LS for Leos.
73, Ed - KL7uW
At 06:49 AM 6/1/2010, Tim - N3TL wrote:
>Hi Alan,
>
>Your comments suggest that I'm the one in Bizarro World.
>
>Regarding the One True Rule - I operate under
>the impression (which, I thought, has been
>backed by science) that regardless of the
>frequency pair, Doppler always will have a more
>pronounced effect (in relative terms, of course,
>based on the frequencies being used) on the
>higher of the two. In a perfect world, ever
>operator will be tuning for Doppler the same
>way. reality, of course, is that some people
>either can't use computer-aided Doppler tuning
>(my situation for the first several months that
>I worked the linear satellites) or they choose
>not to - as I still often do. And when I do, I
>will continue to compensate - most - for the
>frequency being most affected by Doppler, which is the higher frequency.
>
>Regarding mid-pass - My experience suggests
>that, while your statement about mid-pass
>Doppler shift is accurate, it does not take into
>account that mid-pass occurs for only a moment
>in time during any orbit. My experience has been
>that the lower a satellite's orbit, the more
>significant Doppler movement will be. VO-52 is
>the prime example, in my opinion. And here, for
>me, the time just before and just after (say,
>20-30 seconds on each side) mid-pass is when
>Doppler affects the uplink frequency the most.
>The computer and software I use often have not
>been able to adjust my radio's frequency as
>quickly as they need to in order to compensate
>for Doppler. Others may not have that problem
>with their computer-tuning system, but I believe
>the more-rapid Doppler effect is consistent for
>VO-52 regardless of how one is tuning. I'm
>confident (and, actually hope) that others will
>correct me if I'm wrong about the relative speed
>of Doppler correlating to the relative
> height of a satellite's orbit.
>
>Regarding pride associated with the decision to
>not use current technology - Any measure of
>pride I take from knowing how to routinely tune
>for Doppler manually comes from the knowledge
>that circumstances and situations may arise when
>I will be asked to communicate effectively
>through the satellites without access to
>everything associated with current technology.
>My station is founded in that concept. I don't
>have an all-mode, full-duplex radio. I use two
>radios with a diplexer connecting them to one
>antenna. I don't have an az/el rotator; well,
>actually I do. It has three parts - shoulder,
>elbow and wrist. I don't have two very large,
>high-gain antennas. The only satellite antenna I
>own and use (other than some whips for the HTs)
>is the Elk dual-band log periodic. All of that
>being said, I am proud to say that I can use the
>gear I have to work any of the current fleet of
>single-channel-FM and linear-transponder
>satellites from anywhere - even without
> access to a computer or even to power. In that
> regard, Patrick - WD9EWK - has been an
> inspiration and mentor. His station is similar to mine.
>
>I can't comment on your last two statements
>(about SSB vs. FM satellites and how to
>appropriate use a Yaesu FT-736r) because I
>didn't comment initially on either one.
>Personally, I find the FM satellites easier to
>work than the birds with linear transponders -
>but the latter are easier to make contacts on
>because they never attract nearly the number of
>operators on a single pass as the FM satellites.
>NONE of them are as difficult to work as I
>believed. They represent the most fun and
>satisfying operation I've ever done in amateur radio.
>
>73 to all ... from the EM84 chunk of Bizarro World....
>
>Tim - N3TL
>
>
>
>________________________________
>From: Alan <ve4yz@xxxxxxx.xxx>
>To: amsat-bb@xxxxx.xxx
>Sent: Tue, June 1, 2010 9:31:36 AM
>Subject: [amsat-bb] Re: Doppler Tuning Convention Question
>
>Folks I've been patiently silent reading this d?j? vu annual discussion and
>I'm getting a brain crap.
>
>- comments that tuning the highest frequency is the "One True Method"
>Yikes! Why is that? So you can leap frog down the pass band and eventually
>stomp all over a QSO where folks are tuning both TX and RX to maintain a
>single constant frequency at the satellite?
>
>I've read the " Doppler tends to move more quickly near mid-pass than the
>computer and software routinely seem able to keep up". Mid pass is when the
>sat is moving most tangentially to you at which point Doppler shift is nil.
>
>
>I've read statements from many taking pride in their lack of use of current
>technology.
>
>I've read that working tight SSB sats is easier than the wide band FM where
>the satellite is very forgiving of your sloppy tuning.
>
>I've read advise to someone using an FT 736r that your shouldn't tune the RX
>and ignore the use of the NOR/REV feature, again so you can eventually stomp
>on other QSO's as you slide down the pass band.
>
>Have I just been transported into a Bizarro World?
>
>
>
>73, Alan VE4YZ
>EN19kv
>AMSAT LM 2352
>http://www.wincube.ca
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
>Not an AMSAT-NA member? Join now to support the amateur satellite program!
>Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>_______________________________________________
>Sent via AMSAT-BB@xxxxx.xxx. 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
73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-600w, 432-100w, 1296-60w, 3400-fall 2010
DUBUS Magazine USA Rep dubususa@xxxxxxx.xxx
======================================
------------------------------
Message: 9
Date: Tue, 1 Jun 2010 11:58:28 -0700 (PDT)
From: Tim - N3TL <n3tl@xxxxxxxxx.xxx>
Subject: [amsat-bb] Re: Doppler Discussion
To: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>, amsat-bb@xxxxx.xxx
Message-ID: <27621.96392.qm@xxxxxxxxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset=us-ascii
Clint,
Thank you for this. Please note that I got a "broken link" window when I
tried to go to that page.
73,
Tim - N3TL
________________________________
From: Clint Bradford <clintbrad4d@xxxxxxxxx.xxx>
To: amsat-bb@xxxxx.xxx
Sent: Tue, June 1, 2010 12:49:35 PM
Subject: [amsat-bb] Doppler Discussion
>> ... Doppler always will have a more pronounced effect (in relative terms,
of course, based on the frequencies being used) on the higher of the two ...
Here's the actual equation for determining Doppler shift ...
http://tinyurl.com/calc-dopp
Your generalization is correct. On a 45 degree pass of a sat that's in a
circular orbit at 497 miles up, approximate Doppler shifts calculate to ...
At 15m, +/- 477 Hz
At 10m, +/- 659 Hz
At 2m, +/- 3.27 kHz
At 70cm, +/- 9.76 kHz
At 23cm, +/- 28.5 kHz
at 13cm, +/- 53.8 kHz
Clint, K6LCS
http://www.work-sat.com
_______________________________________________
Sent via AMSAT-BB@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
_______________________________________________
Sent via amsat-bb@xxxxx.xxx. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
http://amsat.org/mailman/listinfo/amsat-bb
End of AMSAT-BB Digest, Vol 5, Issue 246
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