From : PC1L ( ex PA3GJE ) @ ON0LGE
to   : satellit @ ww
sub  : AO-51 Echo Contact

Maastricht 16 Aug 2004

After a short try ( testing the sub command tone CTCSS 74.4 Hz and PL 67 Hz ..... hi hi ) 
via SO-50, 15 Aug ( worked Jep, F6BYJ in JN05FS ), 08:46 UTC, ( audiosat22.wav in site ) I 
decided to make another try, concerning AO-51 Echo. 
During orbit 660, AOS, I listened carefully for a while on the TXB frequency. The signals 
were very good and stable too. CQ from ON4BK, DK1NR, UT5UAR, DG2BCA and RV3EAX. ON4BK in 
JO20FM had a QSO with DK1NR in JN59MI. After it and several CQ's from the other stations I 
gave my callsign and could receive it on the downlink ( less uplink noise ). 
So I came back again with my callsign and then I called RV3EAX hi. I could not hear RV3EAX that 
moment but ON4BK came back ( MA PHASE 27 AF ) ! We had a short contact, 10:29 UTC 
( audiosat21.wav in site ). The ON4BK input was 100 % ( no uplink noise and clear audio ). 

I digitalized the recorded audio, I placed it in the site : www.qsl.net/pa3gje/ 
You can find it in : AUDIO ( QSO ) or in : YOUR CALLSIGN ( go to ON4BK ). 

Sometimes stations could hear a part of their transmission on the downlink, then nothing 
anymore, only the TXB carrier was there. As if you are no longer on the input ! 
It seems the RX sensitivity is bad and the sat can not receive your signals but that is 
not true ! Often it has to do with unwanted mix or strong carriers without modulation 
( no PL tone ). After the disturbings you can continue. In my second answer to ON4BK I did 
so ( mentioning the 'missed' part of qth locator hi :-) ..... 

During the test period the best thing you can do is use 'full duplex' to have a good 
coordination ! Further, if there are very strong stations working it is a fact the weaker 
stations do not come over. 

The downlink turnstile system ( Mary array ) works excellent ! It delivers a VERY good and 
stable signal even if you work with LIN antenna's like a rubber duck etc. Several 
attitudes of your HT are possible. 
 
The receiver/uplink antenna combination is very sensitive and this configuration delivers 
very good results on the uplink. Remark : the 'attitude' of your HT is IMPORTANT now ! 
( Because of the satellite uplink antenna ( LIN, no CP ! ). Beware mismatch. 

Wish You All Success with the Satellites, in this case ofcourse AO-51, Echo ! 

73, Leon ((-,O)) PC1L. 

pc1l@amsat.org
pc1l@qsl.net
www.qsl.net/pa3gje/ ( i-mode, same url )
www.qrz.com/pc1l/
www.qrz.com/pa3gje/