Satgen47   Heavenly Mail Boxes

On Sunday 11 Feb , 4 days after launch Jamsat switched on the JAS1-B digi
beacon on 435.91 MHz, simultaneous with transmissions from the JA morse
beacon 435.795 and the JA transponder 145.9 to 145.99 up, 435.9 to 435.8
down. By Wednesday 14th JAS1-B was operating digipeater with DB2OS the
only station read. Then on Friday 16th it came back on digipeater and I
managed to access briefly with DB2OS who was accessing firmly. Finally on
Sunday 18 Feb I interupted breakfast to access the first JAS1-B mail box
orbit audible in UK. 

The large number of stations accessing the bird was a complete surprise
and in the orbits which followed I saw more than 40 different callsigns
from EA, DL, HB, YT, OE, ON, OZ, SM, GM, KB and 6 or 7 US call areas. I
saw no Gs on Sunday but on Monday, I noticed G2BFO was already among the
messages and doing fine.

Access quality seems to divide squarely into 2 groups. Those who use
direct Tx Audio feed and get firm access, and, those who put the TX Audio
into the mike socket where it subsequently gets pre emphasised. Clearly
this latter group get much poorer results. JAS1-B likes a clean signal as
Heinz DL1CF pointed out nearly a year ago in Practical Wireless for April
89. So if you have'nt got direct feed , a mod would appear to be required,
(see also RadCom p60 for Feb 90, for a 9600 baud direct feed mod which is
what this JAS1-B AFSK 1200 bps seems to need ).

Lusat short bulletins say they will put a Digipeater on in the next few
days ( remember this needs a BPSK rx modem ( G3RUH ) and a modified TNC ),
and in addition Pacsat announces that a Digipeater will shortly be
provided for our amusement, as the Control stations continue to load the
Mail box software. Equally interesting the S band signals should be coming
down this week. Look out for fantastic doppler shift of plus or minus 54
Khz on overhead passes. Centre frequencies should be :- Pacsat 2401.1428
Dove 2401.2205 at CPA nearest approach centre of pass ( better to listen
at start or finish of a distant pass about 30 Khz up at start, 30 down at
end to take advantage of slower doppler rate ).

Meanwhile Congratulations to all concerned. In 15 years of sat operating,
last week was the best ever, when amongst other things I collected my
first couple of satpac msgs from 8J1JBS. 73 de John GM4IHJ@GB7MAC 21 Feb.