Over the last week or two, I have been getting a 200 Hz discontinuity jump
in my uplink frequency at TCA (Time of Closest Approach), also known as the
zero doppler point. This happened on every bird, every pass. (all mode B,
70cm up, 2m down)
AOS was early, LOS was late, and doppler tracking was non-linear and had
the bad jump at TCA.
Today, thanks to K5GZR and KB7IJ, the problem source was identified and
corrected.
It was caused by a terrible error in the definition of my Home Altitude. I
typed in, 350 meters. The program took it 35,000 meters.
I corrected it and now doppler tracking in SDRC v3.x is perfect.
If anyone else ever gets a set of symptoms like mine, take a look at your
Home QTH altitude setting. Being off by a factor of 100:1 makes a
difference.
73, N0AN
Hasan
< but I'm wondering if the marker would be sufficient evidence? Depends who placed it, I suppose?> I live near the intersection of 4 grids. It is in a subdivision. There is a bronze marker placed near the curb, explaining the meaning of the grid lines and longitude and latitude. BUT, the actual intersection is across the street, in someone's front yard, not at the curb, where the plaque is placed. You have to rely on your GPS, or one of several grid mapping programs that you can enlarge and do a print screen. Both will work. I use a hand held GPS for this and also for geocaching. Brad KC9UQR
For my information, as I am not much of a rover, but as I may be doing a
little local grid rove sometime next weekend by request, how far from a grid
boundary can you be for it to count? I found a 4 corners grid boundary in
my area, but it is way rural in a deep clump of vegetation with a dirt road
a couple hundred feet away. What is the maximum deviation from an X
.000000; Y.000000 location for it to be legal as a 4 grid location? I will
probably do a much easier 2 grid line location, but just wondering.
Thanks much.
Tom Schuessler, N5HYP
EM12ms
Gerald,
https://www.sdr-radio.com/download
...and I listed the program by name in my prior message and when I googled
that name I got several listings like the url post immediately above.
Did google not work for you?
You might find this particularly interesting where the options in the
satellite pane of the software are discussed.
https://www.sdr-radio.com/options
It is free, for amateurs, btw.
73, N0AN
Hasan
On Sat, Aug 29, 2020 at 1:38 PM Gerald Payton <gp_ab5r(a)outlook.com> wrote:
> Is this program TOP SECRET or can anyone look at it? I'm new and trying
> to soak in these things. But just talking about it and not supplying a URL
> does not help.
>
> 73,
> Jerry AB5R
>
> ------------------------------
> *From:* AMSAT-BB <amsat-bb-bounces(a)amsat.org> on behalf of Hasan N0AN via
> AMSAT-BB <amsat-bb(a)amsat.org>
> *Sent:* Saturday, August 29, 2020 1:15 PM
> *To:* Bruce Perens <bruce(a)perens.com>
> *Cc:* AMSAT-BB <amsat-bb(a)amsat.org>
> *Subject:* Re: [amsat-bb] Doppler Tracking Discontinuity at TCA - Problem
> Solved
>
> Hi Bruce,
> I'm sure it should be error trapped when an absolutely crazy value is
> input, but I'm not pointing the finger at any programmer, when I, in fact,
> input the wrong, really wrong, value.
>
> I'm just glad I found it and now doppler tracking is perfectly even on an
> 89 degree overhead pass.
>
> Considering all the things done right in the software, way beyond any other
> program I've seen, I'm not going to complain.
>
> The program auto-schedules, tracks, prioritizes and presents for decoding
> AO-73, EO-88, JO-97, AO-91 and AO-92, with no operator intervention
> whatsoever. Any number of birds can be added or deleted.
>
> I can let it run overnight and come down and see every bird's TLM perfectly
> decoded.
>
> If I chose to, I could have it IQ record every pass and go back and decode
> it again later.
>
> The program is absolutely amazing. The fact that it accepted a ridiculous
> input value from me without warning me, is to my way of thinking, small
> potatoes. :-)
>
> (SDR-Radio Console v 3.x )
>
> 5 EL Yagi > 60' Hardline > Duplexer > ARR GasFET > Funcube Pro+ SDR >
> SDRConsole v3
>
> Rotor control by SDRC > PSTrotator
> 15 deg uptilt yagi (5 EL on 2m, 8 EL on 70cm, interlaced, common feedpoint)
>
> Anyone using an SDR that has not used SDRC for controlling it, for
> satellite work, has no idea how enriching an SDR setup with good software
> can be.
>
> 73, N0AN
> Hasan
>
>
> On Sat, Aug 29, 2020 at 12:52 PM Bruce Perens <bruce(a)perens.com> wrote:
>
> > It's a software bug when the software quietly accepts an impossible
> > parameter.
> >
> > On Sat, Aug 29, 2020, 6:17 AM Hasan N0AN via AMSAT-BB <
> amsat-bb(a)amsat.org>
> > wrote:
> >
> >> Over the last week or two, I have been getting a 200 Hz discontinuity
> jump
> >> in my uplink frequency at TCA (Time of Closest Approach), also known as
> >> the
> >> zero doppler point. This happened on every bird, every pass. (all mode
> B,
> >> 70cm up, 2m down)
> >>
> >> AOS was early, LOS was late, and doppler tracking was non-linear and had
> >> the bad jump at TCA.
> >>
> >> Today, thanks to K5GZR and KB7IJ, the problem source was identified and
> >> corrected.
> >>
> >> It was caused by a terrible error in the definition of my Home
> Altitude. I
> >> typed in, 350 meters. The program took it 35,000 meters.
> >>
> >> I corrected it and now doppler tracking in SDRC v3.x is perfect.
> >>
> >> If anyone else ever gets a set of symptoms like mine, take a look at
> your
> >> Home QTH altitude setting. Being off by a factor of 100:1 makes a
> >> difference.
> >>
> >> 73, N0AN
> >>
> >> Hasan
> >> _______________________________________________
> >> Sent via AMSAT-BB(a)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: https://www.amsat.org/mailman/listinfo/amsat-bb
> >>
> >
> _______________________________________________
> Sent via AMSAT-BB(a)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: https://www.amsat.org/mailman/listinfo/amsat-bb
>
