[Fwd: Re: ISS configuration]

[Philip Miller Tate]

Thanks, Terry. Based on this response and my reception experience, I'm guessing that antenna 'shadowing' was not the cause of recent ARISS school contact problems. In fact, I have been impressed with how easy reception has been, especially with a sub-30UKP Baofeng UV-5R.

Phil M1GWZ


Terry McCarty - WA5NTI <3t3 at comcast.net> wrote:

>Phil (M1GWZ) -
>
>I passed your question on to a friend of mine - WA5NOM.  He (Gilbert) and I are from neighboring home-towns in Western Oklahoma and we went to college together (both specializing in math and physics).  Gil is a retired NASA engineer who is still very active in he ISS project.  His response is attached below.
>
>Hope this helps.
>73 de
>-- Terry McCarty 3t3 at comcast.net President - AMRAD wa5nti 
>
>-------- Original Message -------- Subject: Re: ISS configurationDate: Wed, 04 May 2016 02:27:30 -0500From: Gil Carman <gil77546 at sbcglobal.net>To: 3t3 at comcast.netReferences: <57298697.9020303 at comcast.net> 
>
>Terry,
>
>The ARISS 2 mtr FM voice contacts use the same VHF whip antenna
>for both the uplink and downlink.  This antenna is mounted on the
>bottom of the ESA Columbus module.  They do have different primary
>and backup uplink frequencies, which can be switched if reception
>problems are encountered onboard.  The Ham Video and audio downlink
>on 2.4 GHz is also used on some of the recent U.K. ARISS contacts,
>and it has its own external S-band antenna, also on the Columbus
>module.  See the following link.
>
>https://amsat-uk.org/tag/columbus-module/
>
>Gil, WA5NOM
>
>
>On 5/4/2016 12:20 AM, Terry McCarty - WA5NTI wrote: 
>
>Gil -
>
>I got a question from M1GWZ about ISS having separate uplink and downlink VHF antennas.  Do you know the answer ?
>-- Terry McCarty 3t3 at comcast.net President - AMRAD wa5nti 
>
>-------- Original Message -------- Subject: Re: [Fwd: ISS configuration]Date: Tue, 03 May 2016 17:10:01 +0200From: Philip Miller Tate <philmt59 at aol.com>To: Terry McCarty - WA5NTI <3t3 at comcast.net>CC: AMRAD reflector <tacos at amrad.org> 
>
>Terry - does the ISS have separate uplink and downlink VHF antennas? Only one UK school link has run into difficulties AFAIK and astronaut Tim Peake's repeated calls were clearly audible to me throughout. However, I believe there had been a late change of uplink frequency and this may have caused confusion at the school. Otherwise, UK school downlinks have been very clear even with a simple HT antenna on the ground.
>
>Phil M1GWZ
>
>
>Terry McCarty - WA5NTI <3t3 at comcast.net> wrote:
>
>ALCON -
>
>The following is an extract of a recent email I have extracted from our Woodbridge Amateur Radio Club's effort teaching 5-th graders in a Prince William County School about Ham Radio.  
>
>Figured all of in AMRAD might be interested.
>
>
>-- Terry McCarty 3t3 at comcast.net President - AMRAD wa5nti 
>
>-------- Original Message -------
>
>
>The ARISS onboard antenna is mounted on the bottom (Earth-facing side)
>of the Columbus module, which is on the lower starboard side of the ISS.
>(See the attached .JPG image).  There have been reports of temporary
>signal drop-outs during recent ARISS contacts, especially over the U.K.,
>and we suspect that it might be the result of antenna blockage by the
>four vehicles that are currently docked to the bottom of the ISS.
>So you also might notice some fading or drop-outs in the downlink
>transmissions during the May 6 contact.
>
>The following link has some onorbit video tours of the ISS by
>astronaut Suni Williams that you might find to be of interest
>if you haven't seen them before.
>
>http://www.nasa.gov/mission_pages/station/main/suni_iss_tour.html
>
>
>
>
>
>
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