[amsat-bb] AO-40, BBQ's, etc.

[Scott Townley <nx7u@xxxxxxxx>]

First, gentlemen, I would beg that we keep the LIST friendly.  Stab at each 
other all you want in the dark.  Utilize "reply", "reply to all", and the 
editing features on your addressee list.  If you are concerned with the 
educational aspect of the result (for the list), let us know who lives 
*afterwards*, when the blood is cleaned up.

That said, my unsolicited observations, pointed absolutely nowhere.
1. Building microwave dishes is not the cookie-cutter operation we would 
all like to believe that it is.  There is a lot of variability of equipment 
in use, and plenty of variability (I bet) within each equipment.  If it 
were trivial to slap together a 50% efficient reflector then all the 
commercial antenna vendors, defense contractors, VSAT antenna vendors, 
etc., wouldn't need engineering departments.  So keep in mind that even if 
they look the same from the outside, they don't necessarily work the same 
on the inside.
2. I think one thing that is generally agreed upon is Gene Marcus' link 
budget spreadsheet.  If you're not using it, you should be.  Ferinstance, 
for my little portable BBQ soiree on Monday, I plugged in *optimistic* 
numbers and found that my 20W/9el yagi (13dBiL) on U-band would not get 
anywhere near MB-10dB.  So I didn't worry about it--I can't get there.  Did 
I hear myself?  Yep, the whole time, at 64,000km.
2a. When I'm at home, I use my little "AO40_SNR" version that I came up 
with (don't know if anyone else has ever used it, even though the ANS 
bulletins have been kind enough to advertise it for me for some 
time).  Plug in a Nova pass listing and I know every 10 minutes my downlink 
SNR and the uplink power estimated for that link.  When it says "100W" (my 
maximum amplifier output) I know I can run all-out, and when it says less I 
know when to reduce power, *before* LEILA tells me to.
3. If the specification is MB-10dB, I see no problem running exactly there, 
always.  I know some don't agree.  Oh well.
4. If I cause someone interference, either due to fat fingers, deaf ears, 
or some other malady, I would certainly hope they would point it out to me 
either on the air or privately via e-mail etc.
5. It is good to remember that this whole LEILA thing is new.  In my 
opinion it does not work as well as it should for its intended role (notch 
too wide, siren off frequency doesn't do anyone any good), BUT it certainly 
is better than nothing.  Hopefully it will continue to be improved for 
future platforms.
6. That being said, there is no reason to be afraid of LEILA (see #3).  But 
be cognizant!  If you're talking and your return suddenly gets weaker, TUNE 
AROUND and see if LEILA is sounding (it seems to generally be up-frequency 
on the downlink).  If it is, *stop transmitting*, adjust power, and pick up 
when it's done whining.  My one peeve is many many times people try to talk 
thru the notch.  Does no good at all.

So there.  Feel free to flame me, PRIVATELY.  I will then promptly and 
cheerfully ignore you, privately.  Unless, of course, you agree :-)

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