[amsat-bb] Re: Help for Humber College Students with ISS Contact

[Kelly Martin]

These are the people whose professor famously told the Toronto Star
said that only professional radio engineers had the knowledge and
competency to contact the ISS.  I wrote the professor a letter, but he
never replied.

I suspect their main problem is that they're using an excessively
high-gain antenna, which means it's extremely directional and thus the
targeting has to be very precise.

Also, it might help if they listened on the DOWNLINK frequency instead
of the UPLINK frequency.

Kelly


On Mon, Nov 24, 2008 at 5:20 PM, Ken Owen <n6kth at n6kth.com> wrote:
> Hi folks:
>
> 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.
>
> Thanks!
>
> Ken, N6KTH
>
>
>
> 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
> produces.
>
> 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.
>
> Paul
>
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