[amsat-bb] Re: Subject: Was, Is there anyway to get a linear transponder on the ISS?

[Jeff Moore]

Notwithstanding the difficulties and complexities of getting something 
up to and installed on the ISS, why would we want to put an obsolete 
radio up there anyway?

Seems to me that a TM-D710 would be a much better replacement for the 
D700.  For one thing, it has a built in cooling fan which should take 
care of the cooling concerns.  It's obviously not a linear transponder, 
but then most hams don't have the equipment to use one anyway while most 
of us have VHF and UHF FM equipment.

Coupled with a laptop, it could be used for WL2K comms, APRS and 
straight up packet in addition to plain old voice comms.

Jeff Moore  --  KE7ACY

On 6/2/2013 6:23 PM, K5VOU wrote:
> Thanks for all the input regarding the FM 'repeater' on the ISS. 
> Further research into the issues has enlightened me on the 
> machinations of getting things done on the ISS and the complicated 
> processes of working with such varied national interests.  It is 
> obviously way above my pay grade and with these comments I sadly end 
> the quest with a feeling of not going anywhere.
>
> The Kenwood TM-D700 portion of the Phase 2 Hardware system is 
> apparently overheating.  Possibly because of a lack of airflow over 
> the heat sinks.  Possibly because when it is made available, the duty 
> cycle rises to near 100% and the unit consumes too much power from the 
> ISS power budget. Since the other parts of the Phase 2 system are 
> fulfilling the needs of the ISS and NASA agenda, there are no 
> resources available to correct the problems with the TM-D700. Indeed, 
> replacing it with a linear transponder of equal bandwidth and much 
> reduced power consumption may be a much better solution but there do 
> not appear to be any benefits to the ARISS program to drive the 
> solution.  There was a mention in the paper produced circa 2002-3 of a 
> third phase of the ARISS hardware system to be mounted outside but no 
> mention of such a program since then has been located.
>
> Should others want to pursue a program of getting a linear transponder 
> mounted on the outside of the ISS, I wish you luck and refer you to 
> the document;
> "Amateur Radio on the International Space Station -  Phase 2 Hardware 
> System" by Frank H. Bauer, KA3HDO, Lou McFadin, W5DID, Bob Bruniga, 
> WB4APR, and Hiroto Watarikawa.  Sergej Samburov, RV3DR was also listed 
> but this call sign now returns as belonging to Energia in Russia. The 
> document was found at http://www.ariss-eu.org/phase_2_document.pdf
> on the internet.  Frank is a new Amsat VP in this area, Bob is a 
> participant in this list and Lou is still around too I think. Maybe 
> one or all of them can help.
>
> 73,
>
> Tom K5VOU
>
>
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