[amsat-bb] FM signal on FO-29?

[Hector W5CBF/CO6CBF]

Hi Zach and group

I think, the main problem is they are not always the same stations. I have
heard several different stations in terrestrial QSOs QRMing  FO-29; majority
of them speaking Spanish and without any kind of ID. I have not heard them
recently, though.

73!

Hector, CO6CBF/W5CBF

-----Mensaje original-----
De: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] En nombre de Zach Leffke
Enviado el: Sunday, November 08, 2015 4:54 PM
Para: amsat-bb at amsat.org
Asunto: Re: [amsat-bb] FM signal on FO-29?

well.. when I say students, I meant graduate students at VT that happened to
be in the lab when I was doing the experiment.  They work with me and Bob,
so a few crude words here and there aren't uncommon to them.

But good point, probably not the best thing for a public demo if your
audience is a bit younger.

Actually, I've seen so much FM activity (basically every time I've monitored
FO-29 since we first came online in late september) that I've been toying
with the idea of trying to locate where the source emitters actually are
located based on doppler shift data.  We know the doppler between the
receiving ground station and FO-29, so we can back that out.  We know the
transponder mapping, so we can work through that to determine what the
center frequency is as the signal enters the transponder uplink receiver.
What we don't know is the uplink doppler, because we don't know where the
emitter is and we don't know what exact center frequency they are on (but I
bet you its in 5kHz steps, maybe 2.5kHz).  So we have two unknowns.  I'm
betting there's a way to work through it though, and with enough
observations and by watching the rate of change of the doppler, I bet
there's a way to make an educated guess on what their center freq and
location are.

Or if someone listening knows Spanish and/or Portugese, maybe we could get
lucky and hear what cross streets the taxi is going to (if it is in fact a
taxi).

-Zach, KJ4QLP

On 11/08/2015 05:30 PM, Clayton W5PFG wrote:
> I wouldn't recommend playing the FM audio heard via FO-29 to a group 
> of children. Normally it's not English.  It's most likely NOT a 
> religious broadcast based on their choice of crude words.
>
> 73
> Clayton
> W5PFG
>
> On 11/8/2015 16:13, Zach Leffke wrote:
>> So yes, in the last couple weeks I've seen a LOT of FM activity on 
>> FO-29.  And based on my experience with Friday's pass, which was 
>> ascending, I'm leading towards the Central/South America QRM theory.
>> Lots of strong FM activity as the pass started and the satellite was 
>> over the lower latitudes, but as FO-29 ascended over higher latitudes 
>> towards the north pole, the FM activity died down.
>>
>> -Zach, KJ4QLP
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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