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Re: Mobile/Portable Satellite Operations



John W Lee wrote:

> Unfortunately when the "newer" birds came along, things did not get
> better they got 
> worse due to the weak downlink signals.  Working mobile on AO-51 and
> SO-50 
> is not so easy.  So don't be disappointed if you're not hearing too well
> on your small
> antennas.  That's just the way it is these days.   

I'm fairly new to sats but I've found quite the opposite.  I've been 
licensed since I got my novice in 3rd grade back in the early 80's 
followed shortly by a real "tech" (now tech plus) and finally last year 
got around to upgrading to General mainly because after learning about 
Echo and the FM sats my interested in radio was rekindled enough to make 
me want to finally get active on HF with the old FT-747 my dad replaced 
with a shiny new Icom 756PROII.

I found out about FM sats just a week before Echo launched.  When it 
came on I listened to the first few passes with nothimg more than a 
Alinco DJ-C5t and it's stock antenna which was even broken at the time!

I was amazed that I was able to hear anything!  It wasn't much...not 
enough I'd try to work any of the stations I could hear...but it was 
enough to get me genuinely interested.  I also tried listening to SO-50 
and AO-27 but could barely hear anything on SO-50 and AO-27 was just 
whispers down in the noise and only on real high passes.

Still it was enough to get me looking for a more capable dual band rig 
and finally early this spring I picked up a used TM-733 and built myself 
a handheld yagi.  With the 5/8 whip on my truck and the Yagi built from 
some scrap PVC and house wire following K5OE's plans I started making 
contacts fairly easily with just 10watts of uplink.

That's still my prefered setup since it's easy to work.  I can set the 
733 to xmit on VHF but leave the up/down buttons to tune the UHF VFO so 
with one hand I can work the mic and tune my downlink while I aim the 
antenna with the other.  For logging I picked up a cheap olympus voice 
recorder that I Tee off the speaker connection with the other side going 
to my headphones.   I got the TM for $150, built the antenna literally 
out of trash, and used my existing VHF whip which I only paid $25 when I 
got it.  The voice recorder was $60 but only because I wanted one with 
USB download so I could archive things...the $30 one would work just as 
well.  So for right around $200 starting from nothing a sat station can 
be put together for working the FM birds.

With my little 3 element Yagi I can hear AO-27, SO-50 and AO-51 full 
quieting just as clear as my local 440 repeater.  But AO-51 is always 
the easiest to hear and is nice and clear.  27 and 50 I never hear as clear.

Of course all this got me intersted in more.  I can't afford the radios 
to work any of the SSB birds or HEO's if there were any.  But I can try 
to make my current setup easier to use so I didn't have to run outside 
and point antennas.

I built an eggbeater but without a pre-amp it's next to useless.  Will 
be solving that soon ;)  I can hear bits and pieces of QSO's on 27 and 
51 with the Egg but that's about it, nothing workable.  Maybe with the 
pre-amp it will change but I suspect a rotator is in my future and 
another Yagi.

In the meantime I upgraded my Yagi to a four element build off Jerry 
Clement (VE6AB)'s design.  I made it out of more sturdy materials and 
built it to disassamble and store within itself.  Cost me less than $20 
even using all new materials.  I also picked up a used FT-470 HT (since 
I already have 3 FT-23R's and can share battery packs and speaker-mic.) 
pretty cheap and the past month I've been having an absolute blast 
making handheld contacts on 27,50 and 51.

Surprisingly I use even less power and an old abused AEA collapsable 
whip for the uplink (stuck off my diplexer) and can manage to get into 
all three stats on most passes with that.  Yeah I get stepped on 
sometimes..but overall it's a lot of fun...and just amazing to me what a 
minimal antenna and 5watts of power can do!

I still use the voice recorder and then transcribe into my log after, 
makes things a LOT easier.  I did have a small impedance mismatch on the 
recorder but a little audio transformer fixed that right up.

Photos of my handheld setup are here:
http://jhitesma.smugmug.com/gallery/811690

Believe it or not that jumble is actually organized well enough that I 
can have it unpacked and on the air in less than 5 minutes.

For tracking if I'm just going out for an evening I program the calendar 
in my cell phone to warn me 5 minutes before AOS and use a name that 
indicates the compas point the sat will rise near, what the max 
elevation will be and where it will set.  something like "51-SSW/64/N" 
would mean "AO-51 rising from the south/southwest going up to 64 degrees 
and setting to the north"  From that I know generally where to aim and 
just go by ear as I adjust my antenna for the rest.

If I'll be out for a weekend I use Orbitron to print out a set of passes 
with AOS/max/LOS times.  Used that to make nearly half a dozen contacts 
form the middle of the desert this past weekend.  (though I still 
haven't had time to transcribe my logs of those passes.)

If it wasn't for FM sats I wouldn't have been interested at all and 
would never have become an AMSAT member.  I probably would still have my 
license sitting in my wallet collecting dust too.  But now instead I've 
become active on HF again and in the past year made more contacts than I 
did in the past decade, I've also joined a radio organization for the 
first time in over 15 years because I feel AMSAT is doing some truely 
interesting stuff.

HEO's sound real neat.  And I'd love to work some.  But frankly the cost 
of entry to play that game is just too high.  Between the antenna and 
radio requirements it's just not something I can afford and therefore 
holds little or no interest for me.  Even the LEO SSB sats are out of my 
reach at this time and for the forseable future due to equipment 
requirements.

The big problems are things like pre-amps and downconverters aren't 
cheap.  And all-mode UHF/VHF radios just aren't that common or 
affordable.  Needing one or the other is bad enough but needing both is 
quite a burden on my wallet for equipment that's really only usefull to 
me for satelite work.  And given that satelites always have a finite 
lifespan with lots of risks associated with making them live long 
lives...it's just too much of a gamble for me to invest in.

Though I am keeping my eyes and ears open for a deal on a VHF/UHF 
all-mode and I do have a 2.4Ghz downconverter I'm working on so who 
knows...maybe my budget and Eagles budgets will line up at the right 
time...maybe not.

Either way I'm not too concerned as the FM LEO's are still holding my 
interest just fine.

----
Jason Hitesman
N8INJ
jason@hitesman.com
----
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