The "transmit-at-will" method of split-frequency operation is also inconsiderate, since no attempt at all is made to take turns (with those near you) in a gentlemanly manner. For that we are "rewarded" with a clear downlink... most of the time. I still find unknowledgable people transmitting on the downlink from time to time, and I try to educate them to proper splits and operation so they can make a QSO too.
If you have 10 callers in the Chicago-land area, courteously taking turns calling the ISS on simplex... that may be as much as a 90% reduction in the QRM (only 1 out of 10 calling at a time) from this area.... but probably a little less due to the randomness of calling patterns. I realize the ISS footprint is much larger, and you can't take turns with the whole country... but if every urban area were to operate similarly, there would indeed be at least some reduction in QRM for the crew.
Inconsiderate people on simplex too? Sure, sometimes. But the key is to educate people to proper operation, whether simplex or split. And on simplex, you can IDENTIFY who is inconsiderate of others.
Best regards, Stan/W4SV
On 11 Aug 2006 at 20:17, Robert Bruninga wrote:
Hello again- the astronauts will hear everyone calling whether its split or simplex operation so why not make it
simplex!
Because many of us live near inconsiderate operators that step all Over the downlink by transmitting on the uplink. Simplex is just not a good idea. The downlink should be separate from the uplink so that everyone can hear the downlink without interfererence from uplink stations.
Bob
-----Original Message----- From: sarex-bounces@AMSAT.Org [mailto:sarex-bounces@AMSAT.Org] On Behalf Of McGrane Sent: Friday, August 11, 2006 7:43 PM To: Kenneth G. (JSC-OC)[BAR] Ransom; bruninga@usna.edu Cc: Manned space BBS Subject: [sarex] Re: further late reply regarding ISS simplex
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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