[sarex] Re: TX-Cycle Recommendation?

[Margaret Leber <maggie@xxxxxxxxxxxx>]

Mark Fellhauer wrote:

 > Really?  I can't say as my obervations have been the same.   I'm hearing
 > wide gaps between downlink packets and maybe seeing 4 callsigns per
 > pass.  As opposed to Sunsat or Mir, it's very quiet.

Yes, that what I hear too.

But I'm inferring that silence on the downlink implies chaos on the 
uplink. Since we're "working split", you can't *hear* all the collisions 
that are happening on the uplink. In fact, you'd have to be on-board 
Alpha to hear all that crap. The silent intervals represent the time 
when the ISS digi couldn't pull a coherent packet out of all that noise.

Worse yet, the transmitting stations can't hear each other either...they 
can't wait for the other carrier to drop because there *is* no other 
carrier on the frequency they're listening to.

Ever use VHF AM in a light aircraft? Things (like say on 122.8 MHz on a 
nice saturday morning) are always quiet on the ground; you only hear 
aircraft that are on your frequency, and in your sky.

Then once you're aloft--say up 2,000' or so--you hear 
*everybody*...every aircraft *and* ground station within a 50 mile 
radius or so is now line-of-sight to you. And the ones that are at a low 
altitude or on the ground don't *know* when they're blocking each other 
from your point-of-view...so you get a headset full of heterodyne a lot 
of the time.

73 de Maggie K3XS

-- 
-----/___.   _)   Margaret Stephanie Leber    / "The art of progress  /
----/(, /|  /| http://voicenet.com/~maggie   / consists of preserving/
---/   / | / |  _   _   _    `  _AOPA 925383/ order amid change and /
--/ ) /  |/  |_(_(_(_/_(_/__(__(/_  FN20hd / change amid order."   /
-/ (_/   '  K3XS  .-/ .-/    ARRL 39280   /___ --A.N.Whitehead ___/
/____ICQ 7161096_(_/_(_/__AMSAT 32844____/ <maggie@voicenet.com>

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