[amsat-bb] Recent AO-85 Observations (where???)

Thu Feb 18 00:55:52 UTC 2016

Argh!...

These testimonials of when people heard the satellite and what it took to
hit and where it was in their pass are -meaningless- unless you say where
you are relative to the millions of square miles of the country!

Someone on the west coast will have more than 10 dB better chance with any
satelillite RISING from over the pacific, and someone on the EAST coast
will have more than a 10 dB better change of a SETTING satellite over the
Atlantic.  But unless people say where they are relative to the 3D
geometry of the pass, and the rest of the mass of users and RFI from 350
million other people and their part-15 emissions, any such reports make no
sense to anyone else.  The guys in the Midwest in most of a pass will have
a hard time ALWAYS.

People need to think in terms of WHERE the satellite is with respect to
the other 700,000 hams in the country before any comments on link quality
can make much sense.

The satellite on one's horizon and 1500 miles away is only 500 miles above
SOMEONE ELSE.  That's 10 dB right there...

Soap box off.
Bob, WB4APR

-----Original Message-----
From: AMSAT-BB [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Howie
DeFelice
Sent: Wednesday, February 17, 2016 10:42 AM
To: Paul Stoetzer; Clayton W5PFG
Cc: AMSAT-BB
Subject: Re: [amsat-bb] Recent AO-85 Observations

For what it's worth, I worked AO-85 for the first time this Saturday
morning while sitting in the car using a 19" whip and Yeasu 857. I could
hear the satellite almost at AOS but waited to transmit until sat was
above 30 deg elevation since the 19" whip was 3/4 wavelength at the uplink
freq. Got in the first time and made contact with N1JEZ. I never bothered
to check SWR on this antenna and from the radio display power is down
considerably. I did notice fading as well.

- Howie AB2S

> Date: Wed, 17 Feb 2016 09:13:40 -0500
> From: n8hm at arrl.net
> To: w5pfg at amsat.org
> CC: amsat-bb at amsat.org
> Subject: Re: [amsat-bb] Recent AO-85 Observations
>
> Clayton,
>
> I have observed the same. Over the past couple of months, on directly
> overhead or ascending passes to the east, I could never get in until
> about TCA using about 20 watts to an Arrow antenna. On overhead
> descending passes or to the west, I could not get in after TCA.
>
> Now, over the past few days, it's been much easier to work horizon to
> horizon, but the fading is much worse throughout the pass and I am
> constantly twisting to try to regain the downlink. Some times, neither
> polarity works.
>
> According to DK3WN's Illum program, AO-85 will be in constant sunlight
> until 2/25. We'll see if it returns to it's previous patterns after
> that.
>
> 73,
>
> Paul, N8HM
>
> On Wed, Feb 17, 2016 at 9:08 AM, Clayton W5PFG <w5pfg at amsat.org> wrote:
> > For the past several days, I have observed the following:
> >
> > - On ascending passes, I can activate the transponder at AOS very
easily.
> > Either polarity V or H works.
> >
> > - Previously, I needed 10-15 degrees at times on ascending passes to
> > activate the transponder.  As I approached TCA, the challenge
> > getting in always went away and I could get into the transponder
easily.
> >
> > - Descending passes have never been an issue for me. I could access
> > the transponder at AOS and activate the transponder as low as 0.1
> > degrees elevation.
> >
> > - Downlink receive polarity seems to flip almost constantly or be
> > equal at times.  I'm running a V or H antenna configuration (not
> > RHCP or LHCP.)
> >
> > - Suspected reason is the spacecraft's spin rate has changed with it
> > now in constant sun.
> >
> > - As a result I'm hearing some newer stations working AO-85 with
> > handheld transceivers.  I've worked 2 new stations in the last 2
> > days who emailed me directly after the pass stating they were seeing
some success with an HT.
> >
> > Thoughts/comments?
> >
> > 73
> > Clayton
> > W5PFG
> >
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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