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AO40 success and IT question



First, sorry this report is so late but after copying AO40
last Friday, went out of town for the weekend and returned
late last night. So, here's the report, and a question:

1. Finally, success on the Friday pass of AO-40!

2. Setup: parabolic grid antenna w/vertical polarization --
on the roof this time -- w/TransSystem 3733 and the N
adapter, stub cut, crystal for 144.1 IF, FT-847, laptop with
ao40rcv and InstantTrack.

3. Began hearing the beacon at 1130Z, 56000 Km out. The
signal was fading a lot so no good CRC at that time, and
ao40rcv was finding about every forth block.

4. I had an S5 noise floor from the 3733. The AO40 signal
averaged S6.5 to S7+, but again, with a lot of fading.

5. First question: Would a circularly polarized antenna
eliminate the fading? The fade occurred on every block but I
know the spin is very low right now so I don't think that's
the cause.

6. As the phase increased, I began getting good CRCs - my
notes are at home but I recall the first good CRC was around
MA 250. After that, they got increasingly better to a point
where I was getting better than 80% good blocks! I stopped
listening at 1430Z. At that point the signal was back down
mostly in the noise again.

7. I was using InstantTrack and the InstantTune feature to
tune the 847. I found it was unable to keep up with the
doppler. I had to continually adjust the receive frequency
to keep the decode centered around 1000 Hz. The ao40rcv
frequency display was drifting steadily upwards and it
seemed like IT wouldn't increase the Rx frequency often
enough. It was falling behind almost 1Kz per minute. Anyone
have any explanation for this?

8. My only regret was that because my laptop only has one
serial port, I could choose to either control the rig, or
control the rotator, but not both at the same time (I have a
home brew controller that reads the serial output of az-el
from wisp-dde and points the rotators) .

I guess I have to look at mic-click freq control using the
parallel port. Any other ideas on how to do this? I guess
the ideal would be a TSR program that predictably outputs
the az/el plus the radio control bytes on the same serial
port. That way I can modify my controller software to read
the whole string, break off the az/el from the radio control
bytes and then output the radio control bytes from a second
serial port. The operative word here is predictably. Or I
guess use a laptop with two serial ports.

Anyone have some other ideas?

Anyway, I'm pumped about AO-40!

Next plan is a side-by-side performance test of the 3733/N
adapter; a DEM converter; and a second 3733 mounted on a
grid antenna with the integral dipole, . Anyone know where I
can find an electrically controlled 3PST antenna relay?

73,
Art, N3OY

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