Split operations allows everyone can hear the astronauts talking back all the time.
Kenneth - N5VHO
--- McGrane tmcgrane@suffolk.lib.ny.us wrote:
Hello again- the astronauts will hear everyone calling whether its split or simplex operation so why not make it simplex!
pat
On Fri, 11 Aug 2006, Ransom, Kenneth G. (JSC-OC)[BAR] wrote:
It sounds like your issue is not that split
frequencies are bad but that
multiple uplinks makes it difficult for the crew
to listen to one
uplink. ITU region regulations for ground station
operations are the
culprit. Space has no borders but Earth does so
have of the problem is
getting everyone to agree on a single uplink. Not
everyone in the world
has the same frequency allocations nor do they use
the available
spectrum in their region the same way.
The issue is not the 20-30 miles but the number of
callers in the 2000
km wide footprint. The station has to listen to
all of them. Since you
can't hear all of them, it becomes difficult to
know when someone is
talking or not without guidance from the station
operator.
In the MIR days, the crew did not have the luxury
of near full time
satellite communication that provides voice, email
communication and an
IP phone that lets them make phone calls. If the
MIR crew wanted to talk
to someone, they needed to use the ham radio or
the Russian VHF space to
ground system. The ISS crew has plenty of options
to choose from when
they want to communicate and it depends on the
personality of the crew
as to which ones get utilized.
Kenneth - N5VHO
-----Original Message----- From: sarex-bounces@AMSAT.Org
[mailto:sarex-bounces@AMSAT.Org] On Behalf
Of McGrane Sent: Thursday, August 10, 2006 6:43 PM To: Manned space BBS Subject: [sarex] further late reply regarding ISS
simplex
Greetings from patrick N2OEQ
Despite support of the present frequency scheme
for the ISS I still wish
to disagree with the policy of split operation
with different phone
uplinks.
Back when the MIR was up, the russians operated
simplex and left the
radio on to listen for callers. On several occasions, I called the MIR according
to my tracking program
and was rewarded several times with a response.
With two different uplink frequencies, the
astronauts are less inclined
to leave the radio on to listen for callers.
When there were several callers here on simplex
responding to a CQ call
from the MIR, we acted civilized and took turns
and everyone made
contacts so I dont buy the absolute need for split
operation.
Besides, how many callers could there be within 20
or 30 miles up to the
horizon.
We've had years of robot like amateur radio on the
ISS. How about
loosening the ties!
Thanks for the soapbox..... pat
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