[sarex] ISS-Ham L band contact

[Louis McFadin]

All
For those of you that may be considering trying to make a contact with
the ISS on L band, here is the data you need to help you decide on how
to do it.
The measured sensitivity of the L band receiver on a D700 is -105dBm
for full quieting. The cable loss from the radio to the antenna is
9.3db. The antenna gain is zero db.
The polarization is LHCP. The path loss at the horizon on L band is
-160dB. That means the required EIRP for a full quieting contact at
the horizon is 65dBm. The path loss decreases by 15dB at 80 degrees
elevation so that means you can get full quieting with 50dBm in that
case. To further elaborate if you use a 20dB gain antenna ( a small
dish).
You can do it with 32 watts at the horizon or 1 watt at 80 degrees
elevation.

Good luck with your efforts.
I will try to answer your questions.


Lou McFadin
W5DID
ARISS US Hardware manager