[amsat-bb] Help for Humber College Students with ISS Contact
n6kth at n6kth.com
Mon Nov 24 15:20:18 PST 2008
A student from Humber College (Toronto) has asked me several questions
regarding contacting the ISS. One has to do with receiving a beacon, and
the other has to do with antenna polarization. I've urged him to join AMSAT
and get on the listserv, but in the mean time, I wonder if anyone can help
him out with his questions.
Please reply directly to him (paul_je at hotmail.com) if you can help.
From: Paul Je [mailto:paul_je at hotmail.com]
Sent: Monday, November 24, 2008 1:17 PM
To: Ken Owen
Subject: RE: ISS contact
Say Ken, we've set up our primary station just fine, but I was wondering if
I could ask for your advice. Well, you see, we've tested the transceiver
that we have (the ICOM IC-V8000), and we can transmit and receive just fine
with it on our circular-polarized HyGain 2m antenna. Also, we did a VSWR
test and our loss is minimal with the 75W transceiver that the ICOM
produces. Ok, so here's the problem. Even with all the proper testing
done, we still can't seem to pick up or hear the 166MHz beacon that the ISS
My classmates and I are a bit worried/stressed out. I mean, just on last
Friday, we did a test and someone drove at least 5km away from out college
and heard us fine with the handheld radio he had. We had a signal strength
of 3+ out of 5. He could've drove out even further, but we felt that we did
enough testing to know that any attenuation losses were very minimal.
Well, do you know what the problem could be? Have you heard the beacon?
What does it sound like? Maybe we should delay or advance the rotor by a
few seconds? We're using NOVA software, and it allows us to send our
transmission a few seconds ahead or behind.
Ok, so we have a circular polarized HyGain antenna hooked up to our Yaesu
G5500. Uhm, this might sound dumb but do you know whether we should be
right hand circular polarized or left hand circular polarized? Is the ISS
right hand or left hand on 144.490MHz?
I'm trying to research this, but I'm having the hardest time to find this
information out. Oh, also, since our antenna is circular-polarized, does
the way we set our antenna have an effect on our transmission? I know this
sounds confusing, but let me explain:
If you looked at our antenna from the front so that you could see all the
dipoles/elements both vertically and horizontally to your view, well, should
they be perfectly aligned with one set horizontal and one vertical? Both
the vertical and the horizontal are perfectly 90degrees to each other,
however, instead of being a perfect cross to your view, the elements are
more like an "X" to your point of view (even though both are perfectly
90degrees to each other).
Well, hope to hear back from you.
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