[amsat-bb] AO-51 Mode LS

Matt vk2dag at bigpond.com
Sun Sep 17 18:54:38 PDT 2006

I had some luck with my AO-40 gear, MMDS downconverter - VK5EME 
preamp - 3' BBQ grill.  But very limited comms.  I am at a new 
location and my antennas and rotators weren't adjusted/calibrated 
enough for AO-51, and they were only installed last week.  Got it 
sorted by Friday but az is still off by a couple of degrees.  I kinda 
worked VK2RW Reg on the 13SEP06 @ 11:50z, but all we exchanged were 
call signs and the sat was at it's closest when I heard him/me.  Then 
I lost it.  By Friday and the weekend I was getting maybe 50 ~ 60% of 
the passes to my West, unlike my AO-40 days I have a lot of trees 
around me up to 30 degrees to my East and 15 degrees to my South.

But it still was very tricky to work or find!  SatPC32 couldn't get 
it right for the Doppler so I used my PCR1000 to find the downlink 
dialed in the 910 with the AFC on and i was ok from then.  My uplink 
was a IC-T81a with a 16 Watt brick amp into 25 ele loop yagi with the 
memories set at 10 KHz intervals.  So I think I was getting in ok I 
hope I didn't QRM anyone whilst trying.  I have made some recordings 
of my downlink but it's only me calling CQ I forgot to record the QSO 
with Reg.

With AO-40 it was easy to see how much error I had with my rotators 
and LO of my downconverter and so it made it easy to set up software 
like Satpc32 to accommodate for the difference.  It's very hard to 
get it right will a LEO.  I have started looking at S Band GEO sats 
so that I can remove all the errors in my setup.  But all good ham 
fun I would like to see AO-51 in LS or VS more often in the 
future.  Can AO-51 run LU?  And what is the difference between DOVE's 
downlink and AO-51?  DOVE seemed to be a lot stronger.


More information about the AMSAT-BB mailing list