Re: [amsat-bb] ao-40

["hasan schiers" <schiers@xxxxxxxxxx>]

Don,

Something is wrong. I don't know anything about the 24" dish you are using
but the downconveter is top of the line. Let's look at receive
first...forget the tx side for now. Until you get the rx working,
transmitting is a complete waste of time and will only cause interference to
others.

1. How well are you hearing the beacon?

a. The beacon on 2401.332 should be quite loud at low squint angles (15
degrees or less). With an S3 noise level, you should be seeing the beacon S7
or better on an FT-847 (preamp on). The beacon should be 20 to 28  dB above
the noise in a good system..

b. The UEK 3000 is a GREAT downconverter and you are seeing approximately
the right amount of noise (S3). See next step to verify downconverter and
antenna performance.

c. Can you see an S-meter increase when you point the antenna directly at
the sun? You should be able to see at least one segment of bar graph's
S-meter increase on an FT-847.

d. Are you directly feeding voltage to the UEK-3000, or via the coax. If
coax, are you sure you are getting enough power to the UEK?


2. What kind of feed are you using on your 24" dish?

a. If circular, are you ABSOLUTELY CERTAIN that you have the "sense"
correct? You need Right Hand circular....so if you are using a helix feed,
it needs to be a Left Hand wound helix. The sun would be a great test for
this. If you hear/see sun noise but can't hear the bird well, and you are
using circular polarization, you may have the sense wrong.

b. How long is the feedline and of what type from your dish to the UEK-3000
downconverter?

People are using surplus dishes, some as small as 18", but again, that's a
bit small. The most common antenna I hear on the downlink is the BBQ style
parabolic section dish, typically 30+ inches.

3. Are you ABSOLUTELY CERTAIN you are pointed where you think you are? I
spent two weeks chasing the bird using "by guess an by golly" and "that tree
is at a bearing of...." and got nowhere. I then bought a compass and a cheap
5 dollar inclinometer and have had no trouble ever since.

4. Are you trying to shoot through ANY kind of obstruction, especially LEAFY
TREES or BUSHES. Any kind of vegetation will kill the signal, as well as the
more typical building obstructions. Power lines should not be a problem.

Except for antenna, I have a very similar system to yours and I'm hearing
extremely well. In the little time I've been on the bird, it's readily
apparent that I hear myself much better than most stations hear me. I seem
to hear them better than they hear themselves.

Downlink Setup:

Antenna: 39" BBQ Style Linearly Polarized Dish (HyperLink Tech) 26 dBi
Converter: SSB Electronics UEK-3000, 0.7dB NF, 30 dB gain, 1' LMR 400
feedline
Coax to Shack: 135' of RG8/X (lotsa loss!)
Radio: FT-847 2m rx, internal preamp on.

Uplink Setup:

Antenna: K1FO 22 el yagi, 16 dBd gain on 70cm (linear horizontal
polarization)
Feedline: 130' of RG/8 type coax, 6 to 8 dB loss
Amp: 80w output maximum

Both antennas are only 5' off the ground on a cross boom for testing. I hear
the beacon consistently 25 to 30 dB out of the noise at low squint angles.
My uplink signal is very average at best. I hear well, transmit so so, due
to the factors mentioned above.

Hope this helps ya. 73

hasan schiers, NĜAN
schiers@netins.net

----- Original Message -----
From: "Don Blachura" <hair@adelphia.net>
To: "amsat-bb" <amsat-bb@AMSAT.Org>
Sent: Saturday, August 04, 2001 5:41 AM
Subject: [amsat-bb] ao-40


> Hello, I am using an Airlink 24" dish and a uek-3000 downconverter. Can
work
> the bird when its in my window. but only in cw. The signals for ssb are in
> the noise. I have the dish on my boom and use 70cm for the uplink.  The
> noise on the downconverter is about a s-3 so when I hear the ssb  qso's
Its
> low and in the noise. Downconverter is mounted rite at the dish so the
lead
> is short. Using 9913 coax. Can anyone suggest improvements?
>
> Thanks
>  Don...w2xb
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org