[amsat-bb] Re: Uplink power for working ARISSat-1?

GW1FKY at aol.com GW1FKY at aol.com
Sat Nov 12 15:05:11 PST 2011

Hi John,
With the antenna that you have I am sure that you should have no problem  
hearing your own downlink and maybe getting someone to respond to your  calls.
I had confirmed contacts earlier in the season when ARRISat-1 was first  
making passes and active during daylight hours here in the UK.
My set up is just an "Elk " antenna mounted on a well made tripod, I put  
together a unit with a motor for rotation and tracking via any of the usual  
forms of software available - Mainly use SatPC-32.
I have tried my Kenwood  TS2000 or FT 736 and also an FT857 ( this  does 
not have duplex operation)
In terms of power which was your main question - I am using around 20 watts 
 from the transmitter on UHF
for the uplink on SSB.
This is also my set up  for many other contacts and  operation and also use 
a Kenwood THD 7 for AO-51.
During the past week while ARRIS -1 has once again been in good favour for  
daylight hours I have made regular CQ calls and heard my own downlink but 
sadly  had no response from anyone.
The very short time that you get of course with the satellite switching  
off makes it harder to get into the bird
I listen for the rapid rise in the level of noise generated then use CW to  
look for my downlink ( around 145.290 Mhz)    The signal  level varies 
around   S5 -S6 at best.
Need to make the most of the current favourable conditions for this part of 
 the world as with shorter hours of daylight and with regression it won't 
be long  before loose operation for a spell.
I wish you luck and look forward to hopefully hearing you active so that I  
can get another confirmed contact
in my log.
Congratulations to you on your success with the decoding of the BPSK  - 
Maybe I should also be looking
at following in your footsteps.
Ken Eaton

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