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. In the absence of computer control, the higher of the two frequencies is always corrected because doppler affects the higher frequency more. It does not matter if this is your tx or rx, it is always the higher frequency.
73...bruce
-----Original Message-----
From: "i8cvs" domenico.i8cvs@tin.it Subj: [amsat-bb] Re: A051 Date: Thu Aug 23, 2007 3:04 pm Size: 1K To: "Scott Wilson" s.wilson@yahoo.com, k3szh@netzero.net, "AMSAT-BB" amsat-bb@amsat.org
----- Original Message ----- From: "Scott Wilson" s.wilson@yahoo.com To: k3szh@netzero.net; amsat-bb@amsat.org Sent: Thursday, August 23, 2007 5:38 PM Subject: [amsat-bb] Re: A051
For those more experienced, I do have a couple of questions:
When operating an inverting linear, do you generally transmit on USB and listen LSB or visa versa?
Hi Scott, NW2S
We transmit LSB and we receive USB because doing so many other radio hams dedicated to tropo traffic in VHF/UHF can hear us from the satellite by chance in 2 meters and 70 cm where they normally operate in USB for tropo.
When operating linear, what's the accepted approach to doppler correction? It seems that you would be able to transmit without any correction, but that your receive would vary a lot more - or perhaps again, visa versa?
There are various preferences but since OSCAR-6 I prefere to keep constant the frequency of my return SSB signal while manually correcting the TX frequency to keep my voice constantly clear while speaking. If the operator in contact with me do the same then our QSO start and end on the same frequency during the whole orbit. I prefere to use separate RX and TX and in my case they are nothing special very old and mostly homebrewed equipments.
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]
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" mvermeer@skynet.be To: "'Bruce'" KK5DO@amsat.org; "'AMSAT-BB'" amsat-bb@amsat.org 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]
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participants (3)
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Bruce -
Marc Vermeersch -
Roger Kolakowski