[amsat-bb] Re: Bob's Message
broberts at mta.ca
Thu Dec 13 16:03:34 PST 2007
Quoting Joe Krepps <occupant at ytpress.com>:
> > Dave Guimont wrote:
> >>>The reason for Echo (a two-user FM voice) escapes me also, Greg.
> >>>To me, money down the tubes...
> > I'll agree with that one also, a whole bird with one "Channel"
> > like a HUGE waste. Cool? Yeah,, but single user uh,, nah.
> I respectfully disagree. I'm very happy to get involved with birds for
> the second time, thanks to Echo. There was a time when I had an IC-820H,
> Yaesu dual axis rotors, HyGain(?) CPs for 2m & 70cm. It was all just a
> bit much. This was (probably) before MacDoppler so I was struggling with
> tracking and predictions. It sure was cool looking but I never got my
> use out of it. Sold the stuff for a song. Not a good song either!
> Getting my feet wet...again...with an Arrow and my FT-817ND and/or
> FT-470 is perfect for my current situation! I wouldn't be on this list
> if it were not for the FM birds.
> If no one else will stand up for them, I will! Not arguing the value of
> HEOs but my sincere thanks to those who made the LEOs possible!
> If it gets more people involved, why not? If it keeps them around for
> HEOs, isn't that good? "Real soon now" I'd love to take a stab at AO-7
> with my setup + extra bits (preamp, maybe a bigger antenna.), correct
> modes of course. Will I get many complaints if I only shoot 5w, CW/SSB,
> at AO-7 from my LEO rig???? I'm really a 20m guy. (Well, what else can
> you do with 5w when you're mobile?)
> Joe WB3CFN
To start with your last question, I think it's accurate to say that nobody
complains when a station is too far into the noise. I worked AO-7 with a
pair of FT-817s for over a year and had a hoot, though 5w up on a small
yagi will do better with CW than SSB. Sometimes folks will tell you they
simply can't hear you, and then you can look at the map and see if this
means your setup is better or if they are dealing with greater path loss.
Other times, you struggle and your companion doesn't, and that creates new
questions: is my beam pointing off, do I need better cable.
In my experience, AO-7 is quite variable in the downlink power for a given
uplink power. This experience is gained not only when there are others on
the band who might be changing the available power, but also testing it in
relative silence. Experimentation is the name of the game.
You didn't mention VO-52: now there's a wonderful SSB bird to use as a
stepping stone from the FM ones. Point your Arrow in the right general
direction and look for the beacon, which is a continuous tone. It will, of
course, be the only one that is slowly dropping across the band, so you can
distinguish it from the tones that come from your neighbor's flukey VCR :-)
Many have had success operating into it half-duplex handheld with a
FT-817. I'd like to wire up something like the Nokia 810 pocket computer to
do automatic doppler in the field. The constant-tone beacon lends itself to
many interesting experiments, in my case showing just how badly the house
attenuates 2m when the bird dips down behind it!
To address some of the recent general discussion on the list, it is very
exciting that emerging space-faring nations like India and China are
following in the US's footsteps by using amateur payloads to improve their
international stature and to educate their people. Just as in the US, it is
possible that these nations will eventually launch amateur HEO's for the
same purpose before their capabilities are fully commercialized. We should
cheer them, support them as they wish us to, and make grateful use of their
equipment. Go CAS-1, go Hamsat2!
Furthermore, if we use this forum to announce or just bounce around cool
ideas for payloads and modes, we just might see them implemented in Asian
birds in the near future. That's why Eaglepedia is a great project, and why
I think we all feel that Fred's work is by no means lost, even if it
doesn't fly exactly as he built it this past year. With any luck, the
designed found there will make their way into not only a P4 bird, but into
other projects around the world.
Oh, and the PSLV launch that will include Delfi-C3 is now scheduled for
around Jan 25th, not the earlier date I mentioned before. I should know to
always consult W0RPK's excellent site
More information about the AMSAT-BB