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

[Gabriel Zeifman]

Okay, first off, SatPC32 and other computer control software has done this
exact thing for years. And it has effectively done it without sending
garbage signals. There is also FlexTune which sends a tone to initially
calibrate, then the rest of the Doppler corrections are done mathematically
vs continuously sending garbage. Another thing of note, you're already
sending your voice, why add more? The other software is initially
calibrated manually then continues track with that offset automatically.
Seems better than loading a transponder with even more nonsense.

Personally, I don't see why people consider the linear transponders to me
so mystical. They're simple: signal goes in one point, out the other. Big
whoop. To tune just use a little bit of basic math skills that a 2nd grader
should possess and then turn the knobs till the voices sound right. Pretty
easy, right? Instead we have people who I've never heard on any satellite
(in my two years and 10,000 sat QSOs) suggesting complex and unnecessary
things to make operating on these satellites "easier", when most competent
ops already find them plenty easy.

73,
Gabe
AL6D/actuallyoperateslinearsats

On Fri, Apr 13, 2018 at 7:53 PM, Eric Fort <
eric.fort.listmail at fortconsulting.org> wrote:

> Computer control or actually a variation of such *IS* what I’m considering
> and proposing.  Yes I have read “the one true way”. I understand this
> manual tweaking is how it’s currently done.  Why however are we adjusting
> only one frequency?  It seems that we can adjust the transmit frequency so
> that it is always the same distance from the beacon as seen by the
> satellite and the receiver can automatically track the subduable tone
> transmitted. This means that you need not drift across the transponder and
> the rx station automatically tracks. What am I missing in this being hands
> off and always on frequency?
>
> AF6EP
>
> Sent using SMTP.
>
> > On Apr 13, 2018, at 7:49 PM, Andy <w5acm at swbell.net> wrote:
> >
> > 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.
> >> _______________________________________________
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> >
> > --
> >
> > Bruce Paige, KK5DO
> >
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> > _______________________________________________
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> > to all interested persons worldwide without requiring membership.
> Opinions expressed
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> _______________________________________________
> 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
>