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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