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CX2SA > SATDIG 25.07.11 05:25l 864 Lines 32679 Bytes #999 (0) @ WW
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To : SATDIG@WW
Today's Topics:
1. Re: Vietnam F-1 CubeSat Video (Clint Bradford)
2. Member Survey (Clint Bradford)
3. Should I abandon full doppler correction? (Tom Schaefer, NY4I)
4. Re: Should I abandon full doppler correction? (Jim Sanford)
5. 100 Degree Passes (Clayton W5PFG)
6. Re: Should I abandon full doppler correction? (KM9U)
7. Re: Should I abandon full doppler correction? (Alan P. Biddle)
8. SatPC32 Band Change? (Paul Delaney - K6HR)
9. Re: Should I abandon full doppler correction? (Stephen E. Belter)
10. Re: 100 Degree Passes (saguaroastro@xxx.xxxx
11. Re: 100 Degree Passes (Larry Teran)
12. Re: 100 Degree Passes (Clayton W5PFG)
13. Doppler Correction? (John Papay)
14. Re: Should I abandon full doppler correction? (Stephen E. Belter)
----------------------------------------------------------------------
Message: 1
Date: Sun, 24 Jul 2011 13:39:21 -0700
From: Clint Bradford <clintbradford@xxx.xxx>
Subject: [amsat-bb] Re: Vietnam F-1 CubeSat Video
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Message-ID: <B4D406B5-AAB2-4455-80C1-283DB9469B45@xxx.xxx>
Content-Type: text/plain; CHARSET=US-ASCII
That background track was the third song selection at my wedding in 1989 ...
Long live CubeSats!
Clint Bradford, K6LCS
------------------------------
Message: 2
Date: Sun, 24 Jul 2011 13:50:41 -0700
From: Clint Bradford <clintbradford@xxx.xxx>
Subject: [amsat-bb] Member Survey
To: AMSAT BB <amsat-bb@xxxxx.xxx>
Message-ID: <D1A198D0-4302-41A0-BE95-204087692475@xxx.xxx>
Content-Type: text/plain; CHARSET=US-ASCII
I have spoken to more than 50 clubs the past three or so years. As I prepare
my presentations,
I always go online and research the clubs. I want to see how they are
"marketing" themselves ...
Only two clubs in my region (Southern California) that I have encountered
have actually prepared
and sent to there membership a "customer/client survey" - a
document/questionnaire asking for
input FROM the membership of what they expect from their club.
And to be successful (in ANYone's definition of "successful") - one must
know what is expected FROM
the club leadership ... as well as what is to be expected from the members.
Which brings me to the Radio Society of Great Britain's recent project ...
http://www.rsgb.org/survey/
They have well-defined what their membership is, and what they expect from
leadership. We ALL can
learn from what they have done. It can be as simple as a membership
mass-email message of,
"What can WE do for YOU?" ...
Clint Bradford, K6LCS
------------------------------
Message: 3
Date: Sun, 24 Jul 2011 17:17:14 -0400
From: "Tom Schaefer, NY4I" <ny4i@xxxx.xxx>
Subject: [amsat-bb] Should I abandon full doppler correction?
To: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <EECDF02D-632B-4C81-8B4C-7FC4A70E0935@xxxx.xxx>
Content-Type: text/plain; charset=windows-1252
Hi all,
I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from Texas.
In both cases, while I am using full doppler correction with my 9100 and
MacDoppler, I suspect they are leaving the transmit frequency fixed as they
both changed frequency. K9CIS on CW was quite extreme in the Doppler shift.
I know that this is a by-product of me using full doppler to listen to
stations that are not, but it seems that the majority of the stations I hear
are NOT using flu doppler. I have asked this question before, but it seems
to be happening more frequently.
Should I abandon full doppler correction? Another less black-and-white step
is that if I hear a station moving to adjust my settings so I am not doing
full doppler.
Has anyone ever taken a survey to see how many satellite users actually use
full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack?NEVER!" I exaggerate but it seems that way. Then again, being a
computer person and having computer capable rigs I realize I am skewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20 years.
Thanks,
Tom
Tom Schaefer, NY4I
ny4i@xxxx.xxx
EL88pb
Monitoring EchoLink node KJ4FEC-L 489389
DSTAR Capable APRS: NY4I-15
------------------------------
Message: 4
Date: Sun, 24 Jul 2011 17:51:13 -0400
From: Jim Sanford <wb4gcs@xxxxxx.xxx>
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
To: "Tom Schaefer, NY4I" <ny4i@xxxx.xxx>
Cc: Amsat BB <amsat-bb@xxxxx.xxx>
Message-ID: <4E2C93D1.4000308@xxxxxx.xxx>
Content-Type: text/plain; charset=windows-1252; format=flowed
All:
For what it's worth, I think I prefer the manual doppler correction on
the highest frequency, which can be done manually.
Full doppler essentially requires constant computer control of both tx &
rx frequencies, AND a whole lot of accurate data.
I've had similar experiences at Field Day, and was able to pick out the
guys doing full doppler, and rarely able to work them.
For whatever my opinion is worth....
73,
Jim
wb4gcs@xxxxx.xxx
On 7/24/2011 5:17 PM, Tom Schaefer, NY4I wrote:
> Hi all,
>
> I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from
Texas. In both cases, while I am using full doppler correction with my 9100
and MacDoppler, I suspect they are leaving the transmit frequency fixed as
they both changed frequency. K9CIS on CW was quite extreme in the Doppler
shift. I know that this is a by-product of me using full doppler to listen
to stations that are not, but it seems that the majority of the stations I
hear are NOT using flu doppler. I have asked this question before, but it
seems to be happening more frequently.
>
> Should I abandon full doppler correction? Another less black-and-white
step is that if I hear a station moving to adjust my settings so I am not
doing full doppler.
>
> Has anyone ever taken a survey to see how many satellite users actually
use full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack?NEVER!" I exaggerate but it seems that way. Then again, being a
computer person and having computer capable rigs I realize I am skewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20 years.
>
> Thanks,
>
> Tom
> Tom Schaefer, NY4I
> ny4i@xxxx.xxx
> EL88pb
> Monitoring EchoLink node KJ4FEC-L 489389
> DSTAR Capable APRS: NY4I-15
>
>
>
>
> _______________________________________________
> 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: 5
Date: Sun, 24 Jul 2011 17:10:04 -0500
From: Clayton W5PFG <kayakfishtx@xxxxx.xxx>
Subject: [amsat-bb] 100 Degree Passes
To: amsat-bb@xxxxx.xxx
Message-ID:
<CAPovOwfhO3gJBsZPZ+nKEopwHC7851xJk_gP-w6CX1PRWk8bEw@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
It's summer time and a lot of us are operating mobile or portable.
Due to the heat and drought conditions here in the US I have named this
summer the "Summer of 100 Degree Passes," commemorating the triple-digit
temperatures.
..and you thought I was referring to maximum elevation / TCA in the subject
line, didn't you?
73
Clayton
W5PFG
------------------------------
Message: 6
Date: Sun, 24 Jul 2011 18:12:19 -0400
From: "KM9U" <arskm9u@xxxxx.xxx>
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
To: "Tom Schaefer, NY4I" <ny4i@xxxx.xxx>, "Amsat BB"
<amsat-bb@xxxxx.xxx>
Message-ID: <BA2BDF0CA49F4F31BA8F00756E2572FB@xxxxxx>
Content-Type: text/plain; format=flowed; charset="Windows-1252";
reply-type=original
I am new to the linear birds and am having the same problem, Tom. It seems
to be kind of a "D*(%#@ if you do and D*(%#@ if you don't" type of thing
with computer doppler control. I have a FT-897 that I have used half-duplex
with CAT control via SATPC32. I have also tried full-duplex using my TH-F6a
as a receiver which, of course has to be manually tuned. Either way, it is
not smooth going. Maybe this is why they call the FM birds "Easy
Sats"...'cuz, so far, the linear birds ain't!
Chuck, KM9U
----- Original Message -----
From: "Tom Schaefer, NY4I" <ny4i@xxxx.xxx>
To: "Amsat BB" <amsat-bb@xxxxx.xxx>
Sent: Sunday, July 24, 2011 17:17
Subject: [amsat-bb] Should I abandon full doppler correction?
Hi all,
I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from Texas.
In both cases, while I am using full doppler correction with my 9100 and
MacDoppler, I suspect they are leaving the transmit frequency fixed as they
both changed frequency. K9CIS on CW was quite extreme in the Doppler shift.
I know that this is a by-product of me using full doppler to listen to
stations that are not, but it seems that the majority of the stations I hear
are NOT using flu doppler. I have asked this question before, but it seems
to be happening more frequently.
Should I abandon full doppler correction? Another less black-and-white step
is that if I hear a station moving to adjust my settings so I am not doing
full doppler.
Has anyone ever taken a survey to see how many satellite users actually use
full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack?NEVER!" I exaggerate but it seems that way. Then again, being a
computer person and having computer capable rigs I realize I am skewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20
years.
Thanks,
Tom
Tom Schaefer, NY4I
ny4i@xxxx.xxx
EL88pb
Monitoring EchoLink node KJ4FEC-L 489389
DSTAR Capable APRS: NY4I-15
_______________________________________________
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: Sun, 24 Jul 2011 17:27:21 -0500
From: "Alan P. Biddle" <APBIDDLE@xxxxxx.xxx>
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
To: "'Tom Schaefer, NY4I'" <ny4i@xxxx.xxx>, "'Amsat BB'"
<amsat-bb@xxxxx.xxx>
Message-ID: <DD988172705E4E4C952B1F5B4107C392@xxxxxx>
Content-Type: text/plain; charset="us-ascii"
Tom,
There was an article in the Journal a few issues back on why the various
manual techniques are only approximations, sometimes surprisingly bad ones.
I think the author's call was WA4SCA. So it does get talked about. With an
accurate clock, and current Keps it is possible to work a full pass and
scarcely touch the dial. It definitely makes it easier to conduct a round
table. If the transponder uses either modes L and/or S, you really don't
have much choice. The change rate is just too fast for practical manual
running, though VE3NPC does an amazing job. Even FM, which is very
forgiving is a challenge for manual tuning at those frequencies.
My default is for full Doppler correction. If the other station is using
it, fine. We can concentrate on communicating. If not, I switch off and do
it the traditional way. It does provide some gentle encouragement to try a
new method, and gives you an opportunity to spread the word. I am
embarrassed at how long I stuck with paper logs amid all this technology. I
experienced a lot of nostalgia when I transferred all my old satellite
contacts to electronic format, but I have never looked back.
Hang in there. As time goes by, you will see more stations using it, as
they won't have to unlearn years of experience. Just remember that it is a
hobby, and there are many for whom tuning and pointing are an integral part
of satellite operations. Have fun!
Alan
WA4SCA
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Tom Schaefer, NY4I
Sent: Sunday, July 24, 2011 4:17 PM
To: Amsat BB
Subject: [amsat-bb] Should I abandon full doppler correction?
Hi all,
I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from Texas.
In both cases, while I am using full doppler correction with my 9100 and
MacDoppler, I suspect they are leaving the transmit frequency fixed as they
both changed frequency. K9CIS on CW was quite extreme in the Doppler shift.
I know that this is a by-product of me using full doppler to listen to
stations that are not, but it seems that the majority of the stations I hear
are NOT using flu doppler. I have asked this question before, but it seems
to be happening more frequently.
Should I abandon full doppler correction? Another less black-and-white step
is that if I hear a station moving to adjust my settings so I am not doing
full doppler.
Has anyone ever taken a survey to see how many satellite users actually use
full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack.NEVER!" I exaggewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20
years.
Thanks,
Tom
Tom Schaefer, NY4I
ny4i@xxxx.xxx
EL88pb
Monitoring EchoLink node KJ4FEC-L 489389
DSTAR Capable APRS: NY4I-15
_______________________________________________
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: 8
Date: Sun, 24 Jul 2011 15:35:24 -0700
From: "Paul Delaney - K6HR" <paul.hamradio@xxxxxxx.xxx>
Subject: [amsat-bb] SatPC32 Band Change?
To: <amsat-bb@xxxxx.xxx>
Message-ID: <3C64DC5E28684D84A5A36CA29503D863@xxxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Hello Erik et al,
I'm using SatPC32 with an ICOM 821H. Is it possible to have SatPC32 change
the up/down band for each satellite? The way I have it working now, I have
to manually swap bands.
Paul Delaney
paul.hamradio@xxxxxxx.xxx
http://k6hr.dyndns.org:8080
------------------------------
Message: 9
Date: Sun, 24 Jul 2011 19:42:48 -0400
From: "Stephen E. Belter" <seb@xxxxxx.xxx>
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
To: "'Tom Schaefer, NY4I'" <ny4i@xxxx.xxx>, "'Amsat BB'"
<amsat-bb@xxxxx.xxx>
Message-ID:
<51668A33220E754EABE6583357ECEE2D79CD544A@xxxxxxxx.xxxxxx.xxxxx>
Content-Type: text/plain; charset="us-ascii"
Tom,
I operated that same pass of FO-29. I started with a nice conversation with
Mike, WA8EBM (Michigan), then moved on to another nice conversation with
Drew, KO4MA (Florida). All three of us were using full Doppler control. It
was great.
I then heard you trying to chase W5BK across the passband. It is a
challenge, and good practice. ;-)
I'm not knocking W5BK or any other operator who isn't using full Doppler.
It takes a lot of skill (a skill I never mastered) and there can be good
reasons for using manual tuning (like running portable). And I'm grateful
for every contact I make, including with W5BK, WD9EWK, and ND9M, all of whom
use manual tuning.
But I agree with Alan, if you're in a position to run full Doppler, do it!
73, Steve N9IP
--
Steve Belter, Indiana Dataline Corp
427 N 6th Street, Suite C
Lafayette, IN 47901-2211
Tel: (765) 269-8521
www.indiana-dataline.net
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Alan P. Biddle
Sent: Sunday, July 24, 2011 6:27 PM
To: 'Tom Schaefer, NY4I'; 'Amsat BB'
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
Tom,
There was an article in the Journal a few issuection. If the other station is using
it, fine. We can concentrate on communicating. If not, I switch off and do
it the traditional way. It does provide some gentle encouragement to try a
new method, and gives you an opportunity to spread the word. I am
embarrassed at how long I stuck with paper logs amid all this technology. I
experienced a lot of nostalgia when I transferred all my old satellite
contacts to electronic format, but I have never looked back.
Hang in there. As time goes by, you will see more stations using it, as
they won't have to unlearn years of experience. Just remember that it is a
hobby, and there are many for whom tuning and pointing are an integral part
of satellite operations. Have fun!
Alan
WA4SCA
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Tom Schaefer, NY4I
Sent: Sunday, July 24, 2011 4:17 PM
To: Amsat BB
Subject: [amsat-bb] Should I abandon full doppler correction?
Hi all,
I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from Texas.
In both cases, while I am using full doppler correction with my 9100 and
MacDoppler, I suspect they are leaving the transmit frequency fixed as they
both changed frequency. K9CIS on CW was quite extreme in the Doppler shift.
I know that this is a by-product of me using full doppler to listen to
stations that are not, but it seems that the majority of the stations I hear
are NOT using flu doppler. I have asked this question before, but it seems
to be happening more frequently.
Should I abandon full doppler correction? Another less black-and-white step
is that if I hear a station moving to adjust my settings so I am not doing
full doppler.
Has anyone ever taken a survey to see how many satellite users actually use
full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack.NEVER!" I exaggerate but it seems that way. Then again, being a
computer person and having computer capable rigs I realize I am skewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20 years.
Thanks,
Tom
Tom Schaefer, NY4I
ny4i@xxxx.xxx
EL88pb
Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15
_______________________________________________
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/ settings: http://amsat.org/mailman/listinfo/amsat-bb
------------------------------
Message: 11
Date: Sun, 24 Jul 2011 17:39:57 -0700
From: Larry Teran <ki6yaa@xxxxx.xxx>
Subject: [amsat-bb] Re: 100 Degree Passes
To: saguaroastro@xxx.xxx
Cc: amsat-bb@xxxxx.xxx
Message-ID:
<CAHMSuG9g8C+ZHVpLgG6OYo9HZt78n-fEPgf-wsxdiSBRmsfLFg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Same temperature here in Imperial Valley, in peak summer we use to
reach 120 F and I have been operating outside all the time as Rick do,
Patrick WD9EWK also knows the conditions of operating outside here in
Souther California Desert.
73's KI6YAA
On Sun, Jul 24, 2011 at 5:19 PM, <saguaroastro@xxx.xxx> wrote:
> Clayton,
>
> 100 degree pass? That's nothing her in DM33... 110 is more the norm......
Since my Station is a handheld, I'm standing out in my backyard with sweat
running down my eyes while trying to keep track of who on and where the
frequency is. Still it fun, though my daughter thinks I'm nuts.
>
> 73
> Rick
> K7TEJ
>
> ---- Clayton W5PFG <kayakfishtx@xxxxx.xxx> wrote:
>> It's summer time and a lot of us are operating mobile or portable.
>>
>> Due to the heat and drought conditions here in the US I have named this
>> summer the "Summer of 100 Degree Passes," commemorating the triple-digit
>> temperatures.
>>
>> ..and you thought I was referring to maximum elevation / TCA in the subject
>> line, didn't you?
>>
>> 73
>> Clayton
>> W5PFG
>> _______________________________________________
>> 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
>
------------------------------
Message: 12
Date: Sun, 24 Jul 2011 20:33:53 -0500
From: Clayton W5PFG <kayakfishtx@xxxxx.xxx>
Subject: [amsat-bb] Re: 100 Degree Passes
To: amsat-bb@xxxxx.xxx
Message-ID:
<CAPovOweATbTcG4XqC_uWEjjWEmXr02yFWUm579CX9hi6Yf0UHg@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
Us Texans are natively equipped to handle these kind of temperatures so my
designation of "Summer of 100 Degree Passes" was intended for our friends in
more northern climates. You guys in the southwest have that "dry heat" HI
HI
The essentials for any summer time remote operations here:
#1 Mosquito repellant
#2 Sunblock
#3 A large-brimmed hat of breathable material (usually goofy-looking and a
perfect fit for nerdy hams)
At least there's one good thing about LEO's for us summer, portable folks:
You don't need to be outside very long to work the whole pass.
73
Clayton
W5PFG
On Sun, Jul 24, 2011 at 7:39 PM, Larry Teran <ki6yaa@xxxxx.xxx> wrote:
> Same temperature here in Imperial Valley, in peak summer we use to
> reach 120 F and I have been operating outside all the time as Rick do,
> Patrick WD9EWK also knows the conditions of operating outside here in
> Souther California Desert.
>
> 73's KI6YAA
>
> On Sun, Jul 24, 2011 at 5:19 PM, <saguaroastro@xxx.xxx> wrote:
> > Clayton,
> >
> > 100 degree pass? That's nothing her in DM33... 110 is more the norm......
> Since my Station is a handheld, I'm standing out in my backyard with sweat
> running down my eyes while trying to keep track of who on and where the
> frequency is. Still it fun, though my daughter thinks I'm nuts.
> >
> > 73
> > Rick
> > K7TEJ
> >
> > ---- Clayton W5PFG <kayakfishtx@xxxxx.xxx> wrote:
> >> It's summer time and a lot of us are operating mobile or portable.
> >>
> >> Due to the heat and drought conditions here in the US I have named this
> >> summer the "Summer of 100 Degree Passes," commemorating the triple-digit
> >> temperatures.
> >>
> >> ..and you thought I was referring to maximum elevation / TCA in the
> subject
> >> line, didn't you?
> >>
> >> 73
> >> Clayton
> >> W5PFG
>
>
------------------------------
Message: 13
Date: Sun, 24 Jul 2011 22:00:21 -0400
From: John Papay <john@xxxxxx.xxx>
Subject: [amsat-bb] Doppler Correction?
To: amsat-bb@xxxxx.xxx
Message-ID: <308968.13328.qm@xxxxxxx.xxx.xxxx.xxx.xxxxx.xxx>
Content-Type: text/plain; charset="us-ascii"; format=flowed
The purpose of full doppler correction is to keep your signal in
the exact same spot on the receiver in the satellite. It has a finite
passband and if you don't correct your uplink, you move within that finite
passband. Theoretically a single linear transponder can support many
conversations but it will not support the maximum unless everyone stays
put at the satellite receiver. Those who don't doppler correct slide
within the
passband and run into those who are staying put. Of course if you adjust
your uplink so you stay put at the satellite, you have to adjust your
receiver to hear yourself because of the doppler shift in the other direction.
Both uplink and downlink require doppler correction in this case.
If you don't have a rig that can be computer controlled or if you are
operating portable and can't readily incorporate a laptop into your
setup for whatever reason, then by all means manually adjust the highest
frequency since that is the one that changes three times faster than the
lower frequency in a v/u satellite. You simply do the best you can.
However, if you have a home rig that can be computer controlled, then by all
means use a computer to adjust your doppler. Stay in one spot in the
satellite's passband. You can make faster contacts since you only have
to pick up the mic to talk or use the key to send cw. If you are working
dx and the window is short, being on frequency and staying put will help
put that distant grid in the log.
The program does all the work but you must be sure that your keps
are current AND your computer clock is accurate to the second. On a
high pass when the satellite is overhead, the doppler changes very fast
and even a few seconds of clock inaccuracy will have you not hearing
yourself in a normal voice. At lower elevations the doppler is not as
severe so a few seconds won't make much difference.
Use the HO-68 beacon to test your doppler correction. Set your radio for
CW with a 500 Hz or better bandwidth. Pick a high pass where the bird will
get up over 45 degrees. Tune the beacon in at your AOS and then don't touch
the dial. If the CW note stays constant over the entire pass, your system
is operating perfectly. Make sure your program settings are such that there
are frequent frequency updates. I have mine set at 1 second no matter what.
Some older radios will not accept frequency changes while you are
transmitting. In
that case, make sure you only key down for short periods of time so the
radio frequency can be updated.
Of course you must adjust your uplink calibration on SatPC32 so that you
hear yourself on the downlink. Hearing yourself in a normal voice will
be an indication that you have your calibration set properly.
Most of the birds stay on frequency, but I've noticed that AO-7 Mode B will
be off by 1700Hz when it changes from Mode A to Mode B. Normally we would
not observe this phenomenon but since lately we have had this mode change
while
over North America we are able to experience it. Within a few minutes, the
satellite is down to a 1200 Hz offset. I'm not sure what happens on the next
pass because it is out of my footprint. The next morning, however, the bird
is back to my normal setting. This means the frequency drifts about 1700 Hz
back down to it's steady state value. The other birds may have some slight
drifting, probably due to spacecraft temperature but it is minimal, less than
a few hundred Hz. So when you are trying to make a contact on the first
AO-7 pass in Mode B, be prepared to readjust your uplink calibration so you
can
hear yourself. It may be as much as 1700Hz at the start.
In my opinion, everyone that can control their radio for doppler should do so.
Doppler correction gives us the maximum usage out of our linear transponders.
Why go through the agony of fiddling with your radio when your computer can
make your life so much easier. You will never have to apologize for not being
on frequency. If I wasn't able to have doppler control on my radio, I
wouldn't
spend much time on the linear birds, unless of course there was a rare grid
to be worked. <grin>
73,
John K8YSE
------------------------------
Message: 14
Date: Sun, 24 Jul 2011 23:16:54 -0400
From: "Stephen E. Belter" <seb@xxxxxx.xxx>
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
To: "wb4gcs@xxxxx.xxxx <wb4gcs@xxxxx.xxx>, "'Amsat BB'"
<amsat-bb@xxxxx.xxx>
Message-ID:
<51668A33220E754EABE6583357ECEE2D79CD5451@xxxxxxxx.xxxxxx.xxxxx>
Content-Type: text/plain; charset="us-ascii"
As far as Field Day and full Doppler correction goes:
>From listening and contacting them during FD, W5MSQ uses full Doppler
correction. Andy MacAllister, W5ACM could tell you for certain. They
finished first in 2007, 2008, and 2010.
John Papay, K8YSE is part of the W8DXA satellite FD team, and they use full
Doppler correction. They finished first in 2009 and third in 2010.
I'm part of the satellite FD team for W9LDX, and we use full Doppler
correction. We finished first in the AMSAT contest in 2006, and second in
2007, 2008, 2009, and 2010. (The 2011 results have not been published yet.)
So for the AMSAT FD contest, full Doppler is the norm for the teams near the
top of the standings.
73, Steve N9IP
--
Steve Belter
-----Original Message-----
From: amsat-bb-bounces@xxxxx.xxx [mailto:amsat-bb-bounces@xxxxx.xxxx On
Behalf Of Jim Sanford
Sent: Sunday, July 24, 2011 5:51 PM
To: Tom Schaefer, NY4I
Cc: Amsat BB
Subject: [amsat-bb] Re: Should I abandon full doppler correction?
All:
For what it's worth, I think I prefer the manual doppler correction on the
highest frequency, which can be done manually.
Full doppler essentially requires constant computer control of both tx & rx
frequencies, AND a whole lot of accurate data.
I've had similar experiences at Field Day, and was able to pick out the guys
doing full doppler, and rarely able to work them.
For whatever my opinion is worth....
73,
Jim
wb4gcs@xxxxx.xxx
On 7/24/2011 5:17 PM, Tom Schaefer, NY4I wrote:
> Hi all,
>
> I just tried a nice pass on FO-29. I heard K9CIS on CW and W5BK from
Texas. In both cases, while I am using full doppler correction with my 9100
and MacDoppler, I suspect they are leaving the transmit frequency fixed as
they both changed frequency. K9CIS on CW was quite extreme in the Doppler
shift. I know that this is a by-product of me using full doppler to listen
to stations that are not, but it seems that the majority of the stations I
hear are NOT using flu doppler. I have asked this question before, but it
seems to be happening more frequently.
>
> Should I abandon full doppler correction? Another less black-and-white
step is that if I hear a station moving to adjust my settings so I am not
doing full doppler.
>
> Has anyone ever taken a survey to see how many satellite users actually
use full doppler. Am I assuming more guys use computers and anyone of the
multiple ways to do computer control that have ben available for years? Does
anyone ever talk about this in AMSAT circles? Sort of like the encouragement
one gives to people afraid of LOTW to try it? "Computers in the
shack...NEVER!" I exaggerate but it seems that way. Then again, being a
computer person and having computer capable rigs I realize I am skewed in my
expectations. I know there are guys working with old 271/471 pairs or even
the old FT726 out there. Great radios and a simple way to do it, but even
they have ways to do full doppler control and they have been out for 20 years.
>
> Thanks,
>
> Tom
> Tom Schaefer, NY4I
> ny4i@xxxx.xxx
> EL88pb
> Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15
>
>
>
>
> _______________________________________________
> 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
------------------------------
_______________________________________________
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 6, Issue 392
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