Re: [amsat-bb] AO40 dish

[Jonathan Naylor <jonathan.naylor@xxxxxxxxx>]

Hi Fred et al

>  Actually, I've wondered if any of the amsat-bb bunch has tried
>  a JT44 QSO with a 7.5'-14' dish with the 25W or so that many have
>  for the AO-40 1269 MHz uplink?
>
>  My understanding is that 100W to 10' is barely adquate for normal CW
>  EME on 1296 MHz.  JT44 should add 6-10 dB to this bringing that type
>  of dish and power level to the realm of possibility.

In last months 70cms and up EME newsletter there is a report of an EME 
QSO between K2UYH (10m dish) and an OH3 who was using 40W to two long 
yagis. Since the polarisation for EME on 23cms is circular, there was a 
presumed 3dB loss there.

I have been asked by HB9Q (http://www.hb9q.ch) to do a JT44 test on 
23cms. They have 400W to a 15m dish (!!!) and are very kean to test 
with satellite class stations. My 23cms system is 100W and a linearly 
polarised 26ele yagi.

I would, except that I use Linux not Windows, and I don't have a sound 
card to radio interface built yet. I am currently writing JT44/FSK441 
for Linux and so that may happen soon. I may pick up an interface at 
Weinheim this weekend.

For those interested, my JT44 for Linux is within 3dB of the 
performance of the "real" WSJT, not bad for only one day tinkering with 
the receive side ! The transmit side works a treat.

>  I'll not be able to put up my 7.5' or 12' dish until next spring,
>  unfortunately, to try it myself, but there seems to be more and more
>  of the group with these "super-TVRO-AO40-dish" setups.

Those sorts of dishes are not so common over here. We didn't have the 
C-band satellite service, we jumped straight to X-band. So we have 
masses of cheap 48/60/90cms dishes here, but nothing much bigger.

>  Fred W0FMS

Jonathan  HB9DRD/G4KLX
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