[amsat-bb] Making the transponder sats as easy as the fm birds

[Andy]

So VERY true!
Thanks Bruce,
ANDY w5acm


-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Bruce
Sent: Friday, April 13, 2018 9:40 PM
To: amsat-bb at amsat.org
Subject: Re: [amsat-bb] Making the transponder sats as easy as the fm birds

Sorry, this theory of thought is incorrect. You must adjust the higher of the two frequencies as it is most affected by Doppler. The true way to adjust is really to adjust both frequencies, however in the absence of computer control of both frequencies, you adjust the higher. Thus, if it is the receive frequency, then you adjust the receive, if it is the transmit, then you adjust the transmit. Holding the transmit frequency on the wrong band will cause you to walk across all the other QSO's taking place which is not a good practice.

73...bruce

On 4/13/2018 8:41 PM, Eric Fort wrote:
> I’ve had an idea for a long time as to making the satellites with linear transponders as easy to use as the FM “easy sats “.  Consider the following:
>
> As I understand it, the goal is to adjust your transmitter such that your frequency at the satellite is constant.
>
> Our tracking program gives us range to the satellite and its velocity relative to us given our location and the orbital parameters. From this we should have computed Doppler for both transmit and receive.
>
> We also know the frequency at the satellite of the various beacons 
> onboard. From this we can measure the doppler and work the other 
> direction
>
> If we transmit a subaudable tone of known frequency we should be able 
> to adjust the rx automatically by tracking the tone. (Acssb)
>
> Given these multiple ways of setting our tx/rx frequencies for our location can this not simply be automated to such a degree as to simply specify an offset from the beacon and operate as if it were a regular predictable opening on hf?
>
> Af6ep
>
> Sent using SMTP.
> _______________________________________________
> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available 
> to all interested persons worldwide without requiring membership. 
> Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA.
> Not an AMSAT-NA member? Join now to support the amateur satellite program!
> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb


-- 

Bruce Paige, KK5DO
                      
AMSAT Director Contests and Awards
AMSAT Board Member 2016-2018
   
ARRL Awards Field Checker (WAS, 5BWAS, VUCC), VE
           
Houston AMSAT Net - Wed 0100z on Echolink - Conference *AMSAT* Also live streaming MP3 at http://www.amsatnet.com Podcast at http://www.amsatnet.com/podcast.xml or iTunes
               
Latest satellite news on the ARRL Audio News http://www.arrl.org

AMSAT on Twitter http://www.twitter.com/amsat


_______________________________________________
Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb