[amsat-bb] A Satellite Weekend!

["hasan schiers" <schiers@xxxxxxxxxx>]

I planned it a week in advance when I saw that I would have Friday through 
Tuesday off, with no other presssing obligations. (4th of July weekend)

First, I had some station work to do:

Station Setup:

2m/70cm nested quads (4 el on 2m, 8 el on 70cm), M2 CP-30 RHC 70cm. Az/El 
rotors (manually controlled), Yaesu GS-800 Az, KR-500 EL. Metal crossboom at 
8'. All antennas fed with 80' of LMR 400, Gasfet preamps for both bands, at 
the antennas. (SSB Electronics)

Rigs: Kenwood TS-2000 (old firmware, no tone on FM satellites), Kenwood 
D7a(g) handheld.

1. Move the 70cm preamp from a nested 2m/70cm quad to the M2 CP-30 14.2 dBc 
right hand circular 70cm antenna. Results: No more cross mod in mode J, 
greatly increased sensitivity on 70cm receive. This opened up Mode J on 
AO-51 and FO-29.

2. Trim the surrounding trees so  I could turn and properly elevate the 
array. This took about an hour with a extensible tree-saw. Results: No more 
hanging up of the CP-30 in the low lying tree branches.

3. Install SatPC32 on the new computer, get it working with the TS-2000. 
(Quite easy since WA4EWV emailed me his doppler.sqf file for SatPC32.)

I printed out all the passes of VO-52, FO-29 and AO-51 for the period I had 
off. (Friday evening through Tuesday evening), and highlighted the best 
passes with a yellow highlighter), then arranged my "schedule", so I could 
catch the best passes to evaluate the system changes I had made.

On Sunday night I had completed all the work and decided to listen to AO-51 
(which I knew I couldn't use because the TS-2000 had no 67 Hz tone in SAT 
mode. AO-51 was pinning my S-meter for most of the pass even with close in 
vegetation losses. Until I got below 10 degrees, it was very strong. This 
got me to thinking that I could use my hand-held on the uplink (since it had 
PL tone). I rigged up a switch so I could switch between my normal setup and 
having the HT do the uplink quickly. This way, I had doppler control of my 
receive frequency, and didn't have to worry too much about doppler on the 
uplink (5 khz max change for the pass) Next AO-51 pass, I made several 
contacts and was quite excited. This struck me as silly, as I've been doing 
sats since AO-6 and practically lived on AO-7, AO-8, AO-10, AO-13 and AO-40. 
An FM satellite? Fun...nah. Actually, the operating techniques for AO-51 are 
so idiosyncratically different from my real satellite interests (linear and 
HEO stuff), that it sort of captured my imagination and I had real fun with 
all of the passes, listening 80% of the time, and popping in for a quick 
exchange a few times each pass. Nothing more than call and grid 
square...this leaves a LOT of openings for others to make contacts. Not 
exactly meaningful conversations, but a very considerate way to share a 
limited resource.

Now, on to the 'real' satellite work with VO-52 and FO-29. I was astonished 
at how much better I heard with the preamp moved to the M2 CP30 RHC 70cm 
antenna. It made FO-29 pure pleasure. When I had open sky, the 4 element 2m 
quad on the uplink only needed 5 watts output (not even considering the loss 
of 80' of LMR-400) to produce a very solid signal. The 2m quad is vertically 
polarized, rear mounted. I ran into a lot of old friends, and made some new 
ones. Signals were just outstanding. As always, vegetation losses from the 
surrounding trees were VERY predictable on Mode J. I could even observe 
shooting between branches, not to mention the regular broad obstructions of 
the trees and adjacent forest a mere 10' away in wide swaths of directions 
(180 to 5 degrees , requiring elevation of > 20, and some places 30 degrees 
to clear enough of the vegetation to not suffer high losses) The losses, as 
would be expected,  were far higher on the downlink (70cm) than they were on 
the uplink (2m). This required careful attention to uplink power. The 
solution is NOT to increase TX power as the RX losses increase...otherwise 
one just becomes a passband hog. Slight increases in uplink power are 
justified by the vegetation losses on 2m, but no amount of uplink increase 
could make up for downlink losses from the trees.

I made lots of FO-29 qsos and even hit one pass where I was really loud the 
entire pass....and NOT ONE QSO! I don't know where everyone was, but for 15 
minutes straight I called CQ briefly, listened, resumed calling CQ, tuned 
the passband...NADA! Very strange.

VO-52 is so loud! The antenna mounted preamp at the antenna (4 element 
vertically polarized 2m quad) really does the job. Very little fading, 
signals 5 to 8 units out of the noise. It reminded me of how much I enjoyed 
mode B on AO-7. What fun! Uplink power on 70cm: 5 watts to the M2 CP-30 RHC 
antenna (up 8' on the cross boom). When in the vegetation, I had to increase 
power to as much as 35 watts to stay in the bird. I could tell how to make 
the adjustments to the uplink, by listening to the passband on 2m. If the 
passband stayed loud, but my sig went in the toilet, it was time to increase 
uplink power. I had to manage my uplink power a lot during a pass to be 
considerate.

On none of the satellites did I find I needed to change polarities. Vertical 
polarization on 2m and RHC on 70cm worked admirably on VO-52, FO-29 and 
AO-51. I saw VERY LITTLE polarization fading. LEOs are nice for that. 
(actually so was AO-40).

I was really bummed out when AO-40 shut down. With a little motivation and 
effort, I have been able to enjoy sat ops again, in spite of no HEO bird. 
The maddening race to adjust my rotors (but not having to do doppler due to 
PCSat32) and carry on a conversation has been quite nostalgic. Planning, 
scheduling and then executing a successful pass can be quite entertaining.

My efforts paid off with many pleasant qso's, and the linear birds (VO-52 
and FO-29) showed many qsos that lasted the entire pass AOS to LOS. The 
"good old days" are back. I have found a "half-full" glass and relegated my 
"half-empty" one to the cupboard.

That's a summary of my weekend. Sat Ops have been lots of fun on this 
"Satellite Weekend".

p.s., between passes 6m opened and I worked a flurry of stations on two of 
the days.

Hope I didn't bore too many of you. I had so much fun, I just had to write 
about it.

73,

...hasan, N0AN
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