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About Last Night...



Hey gang,

Great pass last night but I am a bit puzzled by some things I observed my
system doing....or not doing.
Here's the line-up:

Downlink:
BBQ grill antenna
UEK 3000
FT-736r

Uplink:(U band)
FT-736r
100 watt brick (if needed)
50 feet of flexi IV (same characteristics as 9913)
Homebrew helix with 10 turns...low VSWR

Now here's the problem.
The beacon never got above about S-3 even though the squint was very low.
Signals on the transponder were weak but some were readable and I did make
a few contacts.

Before you say that the system is just deaf, be advised that I could copy
my own downlink (on cw)with only about 1 watt at the antenna at MA 114.
At MA 128, I could still *detect* my downlink (on cw), both by ear and
seeing it on AO40rcv waterfall, with less than .2 watt at the antenna!
That was more than 61000 Km away and I was looking through some trees.
There were no trees in the way when the beacon was S-3 at about MA 47 or
so.  According to the W3PM spread sheet, I should have been seeing a S/N
of almost 20 dB on the beacon.  It was more like 6 or 7 dB if that much.

I seem to be adding 2+2 and getting 3;-)  What are those of you using a
similar system seeing?  It just seems to me that I should be hearing the
beacon and transponder better than I am.

I see about 2-3 dB increase in noise from cold sky to pointing at nearby
trees.  This seem about right?

I think I set Leila off one time when raising the power for test purposes
but it was hard to tell with the idiot with the recording on the loose.
He must, at least, have a good receiver because he found me several times
when I was experimenting with only 1 watt!  It's too bad he gets his kicks
that way instead of making contacts.

Comments?

73...Jim...W5VZF.

Dr. Jim Akers
Dept. of Electrical 
and Computer Engineering
Miss. State Univ. 



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