[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: A Satellite Weekend!



That sounds great.  It is stories like this that made me decide to work 
the satellites.  That and my kids went into euphoric fits when I told 
them that we can use the radios to talk to people on the satellites.  
Sounds like a great weekend.

hasan schiers wrote:
> 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
> ----
> Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
> Not an AMSAT member? Join now to support the amateur satellite program!
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home