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Re: About Last Night...



Jim,

I found last night puzzling myself, but we were in the middle of a severe
downpour with very heavy, moisture laden clouds. The downlink was at least 1
s-unit weaker than normal and I was running more the 3 dB higher uplink
power (and not triggering leila) than I'm used to.

Unfortunately, having just moved my gear into the basement of the new
edition that isn't finished yet, I got caught in five or six rivulets of
water that I had to abandon my AO-40 ops for. What a mess. I plan to be on
this evening around 0000 Z as the bird comes out of the tree line for me.

73
hasan schiers, N0AN

schiers@netins.net
or use amsat.org or arrl.net remailer
----- Original Message -----
From: "Dr. Jim Akers" <jakers@ECE.MsState.EDU>
To: "amsat-bb" <amsat-bb@AMSAT.Org>
Sent: Saturday, September 08, 2001 3:27 PM
Subject: [amsat-bb] 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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>

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