if people would not snip the part out of the original post, you would have seen in my next sentence that I said in the absence of computer control you always correct the higher of the two frequencies as that is the frequency affected most by doppler. It does not matter if that frequency is the tx or the rx, always the higher of the two.
rr on my daughter...boys, school, clothes and cd's take her money hihi she went off to university last week...maybe if she gets a fully automated station at school we would hear from her more often.
73...bruce
-----Original Message-----
From: "Roger Kolakowski" [email protected] Subj: Re: [amsat-bb] Re: A051 Date: Fri Aug 24, 2007 6:03 pm Size: 1K To: "Marc Vermeersch" [email protected], "'Bruce'" [email protected], "'AMSAT-BB'" [email protected]
Bruce (a very influential and integral part of AMSAT) projected:
As doppler affects both frequencies, they should both be corrected using computer control
But computer control may not be available in DX, mobile, remote, battery power, "minimalist" or "emergency" situations.
Computer control is an advancement, it should not keep people off the satellites. If everyone spouts "computer control" you will never give a "newbie" the satellite bug.
I have a QSL card from Bruce's teen age daughter...Bruce, do you think she, as a bona fide Ham Radio operator, has the personal finances available, assuming she is saving for college, to put together a computer controlled SSB satellite station? Why should she be kept off the linear birds because she can only afford an inexpensive 435 SSB/CW rig and a preamp, downconverter for 2 meters to 10? (BTW my 2 kids are licensed also but they are 28 and 24 respectively.)
I believe there should be correction, but it does not HAVE to be "computer controlled," it has to be on a best effort basis.
Roger (first Satellite contact on RS-6 & multi contacts keying an FM rig) WA1KAT
----- Original Message ----- From: "Marc Vermeersch" [email protected] To: "'Bruce'" [email protected]; "'AMSAT-BB'" [email protected] Sent: Friday, August 24, 2007 7:36 AM Subject: [amsat-bb] Re: A051
this method of correcting for doppler is an incorrect practice. It might be fine if you and your buddy are the only two on the satellite. also, notice you say 'you perfer', not the correct method. As doppler affects both frequencies, they should both be corrected using computer control.
Meaning: Keep the frequency at the satellite constant... Right?
Thanks,
//\arc
[snip]
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
On Aug 24, 2007, at 5:39 PM, Bruce wrote:
rr on my daughter...boys, school, clothes and cd's take her money hihi
Bruce, if the boys are taking her money, you need a bigger shotgun. :-) :-) ;-)
Congrats on getting one off to college!
-- Nate Duehr, WY0X [email protected]
I hope this comment will help someone just learning to work the sats. While saying "always correct the higher of the two frequencies" may be good advice-- in modes where the lower of the two frequencies are either 2-meters or HF, but it won't work too well when you get up into using Mode-L or Mode-S.
For the higher frequencies in Satellite communications, throw that notion out the window!
Dopplers vary so much on BOTH frequencies in those cases, that you won't be successful by only correcting the higher frequency.
I know what an advantage "computer-controlled" Doppler correction can be if everything is correct, but I've also used pre-programmed "channel techniques" in several of my satellite radios to work the FM mode satellites, supplementing with fine corrections manually to optimize. (I have an FT-847, two IC-821H's, an IC-970, and an IC-910H, the later of the two having 1.2 GHz.)
I've made some fine L/U contacts on AO-51 lately using two 1.2GHz uplink systems-- one, an array of four 35-element Yagis phased together for low elevation angles, and two, a pair of 24-element Yagis phased together with az/el control.
Do not be discouraged by people indication that "manual control" just doesn't work. It may be quite a challenge, but it works very well! Enjoy the SATS...
73, Charlie, N5TD Temple, Tx
----- Original Message ----- From: "Bruce" [email protected] To: "Roger Kolakowski" [email protected]; "Marc Vermeersch" [email protected]; "'AMSAT-BB'" [email protected] Sent: Friday, August 24, 2007 6:39 PM Subject: [amsat-bb] Re: A051
if people would not snip the part out of the original post, you would have seen in my next sentence that I said in the absence of computer control you always correct the higher of the two frequencies as that is the frequency affected most by doppler. It does not matter if that frequency is the tx or the rx, always the higher of the two.
rr on my daughter...boys, school, clothes and cd's take her money hihi she went off to university last week...maybe if she gets a fully automated station at school we would hear from her more often.
73...bruce
-----Original Message-----
From: "Roger Kolakowski" [email protected] Subj: Re: [amsat-bb] Re: A051 Date: Fri Aug 24, 2007 6:03 pm Size: 1K To: "Marc Vermeersch" [email protected], "'Bruce'" [email protected], "'AMSAT-BB'" [email protected]
Bruce (a very influential and integral part of AMSAT) projected:
As doppler affects both frequencies, they should both be corrected using computer control
But computer control may not be available in DX, mobile, remote, battery power, "minimalist" or "emergency" situations.
Computer control is an advancement, it should not keep people off the satellites. If everyone spouts "computer control" you will never give a "newbie" the satellite bug.
I have a QSL card from Bruce's teen age daughter...Bruce, do you think she, as a bona fide Ham Radio operator, has the personal finances available, assuming she is saving for college, to put together a computer controlled SSB satellite station? Why should she be kept off the linear birds because she can only afford an inexpensive 435 SSB/CW rig and a preamp, downconverter for 2 meters to 10? (BTW my 2 kids are licensed also but they are 28 and 24 respectively.)
I believe there should be correction, but it does not HAVE to be "computer controlled," it has to be on a best effort basis.
Roger (first Satellite contact on RS-6 & multi contacts keying an FM rig) WA1KAT
----- Original Message ----- From: "Marc Vermeersch" [email protected] To: "'Bruce'" [email protected]; "'AMSAT-BB'" [email protected] Sent: Friday, August 24, 2007 7:36 AM Subject: [amsat-bb] Re: A051
this method of correcting for doppler is an incorrect practice. It might be fine if you and your buddy are the only two on the satellite. also, notice you say 'you perfer', not the correct method. As doppler affects both frequencies, they should both be corrected using computer control.
Meaning: Keep the frequency at the satellite constant... Right?
Thanks,
//\arc
[snip]
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
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
participants (3)
-
Bruce -
Charlie Schlieper -
Nate Duehr