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

K5VOU k5vou2 at verizon.net
Sun Jun 2 18:23:51 PDT 2013

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 
"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.



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