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Fun with the portable AO-40 station today



I've wanted to put together a "permanent" portable station for AO-40 for some time, and today looked like as good a day as any for the shakedown cruise.
Equip:
FT-100 (about 20W on 70cm) uplink with 9el vertically polarized yagi
TM-255A, 2'x3' BBQ, fully modified AIDC3733 d/c.  Antenna system courtesy of K5GNA.
Put the antennas up on a 10' tripod/pole.  "Armstrong" azimuth control and minimal elevation control.
Naturally, the biggest obstacle to getting it all together was a missing UHF-BNC adapter that I had to fake.
I ran the d/c from my cigarette lighter adapter and lengths of RG-58 cable, and for the TX just patched a 10' RG-214 extension from my mobile HO-loop to the yagi.

The location was better than home; a clear, flat shot to the east for several hundred feet.  At home I have many 20' trees and a 6' cinderblock wall to deal with.

1. Biggest surprise:  hearing AOS about 4 minutes before NOVA called it.  And I'm further west than my home QTH (where I calculated AOS).  I *never* hear AO-40 at home at AOS; usually takes 2 degrees of elevation or so.  Diffraction?  
2. Biggest problem:  the FT-100 doesn't like to transmit on 70cm.  Never realized this before as it has hardly ever been used to TX on 70cm.  Seems to be some kind of thermal-related issue.  Argghh
Other Notable Things:
3. The elevation nulls of the antenna (ground effect), which I can hear easily on my 2' CP dish at home, were extremely/much more evident on the horizontally polarized BBQ.  
4. The TM-255 detects SSB very well; for my ear much better than the FT-726R at home.  No audio DSP at either location.
5. I need a bit more uplink power, but I already knew that.
6. Need to implement ground-level elevation control too.

Satellite activity before the RUDAK window was quite heavy.  The BBQ seemed to hear well.  Heard my first ZS stations, and worked a new country (HA).  Also matched my best DX with Vitaly, UU9JJ.  So I guess you could say that there was not too much performance penalty for the portable setup!

I'll be back on Friday for the same window to EU...the timing is perfect, right over lunch hour MST!

Scott Townley NX7U
Gilbert, AZ  DM43di

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