%% AO-40 Ground Station Requirements
%% Copyright 2001 Bdale Garbee <bdale@gag.com>
%%
%% Presented in the Dayton Hamvention AMSAT Forum, 18 May 2001
%% 
%% Define the fonts we will use
%%
%deffont "standard" tfont "Arial.ttf"
%deffont "typewriter" tfont "Times_New_Roman.ttf"
%deffont "fixed" xfont "terminal"
%%
%% Default settings for special lines
%%
%%%default 1 leftfill, fore "black", back "white", bimage "background.bmp"
%default 1 leftfill, fore "black", back "white"
%default 2 size 7, vgap 10, prefix " ", font "standard"
%default 3 size 2, bar "gray70", vgap 10
%default 4 size 5, vgap 30, font "standard"
%%
%% Default settings for indented lines
%%
%tab 1 size 5, vgap 40, prefix "  ", icon box "green" 50
%tab 2 size 4, vgap 40, prefix "      ", icon arc "red" 50
%tab 3 size 3, vgap 40, prefix "            ", icon delta3 "blue" 40
%%
%%%%%%%%%%%%%%%%%%
%page
%%%nodefault, font "standard", fore "black", back "white", bimage "background.bmp"
%nodefault, font "standard", fore "black", back "white"

%center
Working AO-40

%size 8
Ground Station Requirements
As We Understand Them Today



%size 6
Bdale Garbee, KB0G
%size 5
<kb0g@amsat.org>


%%%%%%%%%%%%%%%%%%
%page

Overview

	Modes that Work

	S Downlink Equipment 

	U/L Uplink Equipment 

	Performance Issues

	Performance Measurements

	Pictures of Actual Installations

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%page

Modes That Work

Uplinks
	"U" - 70cm Receiver
	"L" - 23cm Receiver

Downlinks
	"S1" - 13cm Transmitter / Dish
	"S2" - 13cm Transmitter / Helix

Modes
	U -> S
	L -> S

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%page

S Downlink Equipment

New S-band Pieces

	Down East 2400-144RX, 1.0dB NF, 20dB gain
	SSB Electronic UEK-3000, 0.7dB NF, 30dB gain
	Down East 13ULNA preamp, 0.7dB NF, 16dB gain

Surplus S-band Converters

	Drake 2880, California Amplifier, Transsystems

Antennas

	Helix, "BBQ Grill", Dishes

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%page

U/L Uplink Equipment

Many commercial "all-mode" UHF radios and crossed yagis
are available for a U uplink.  An AO-10/AO-13 class
station is more than adequate.

The TS-2000, IC-910H, and older rigs like the 736
and TS-790 support 23cm modules with 10 watts.

DEMI, SSB, and others make 23cm transmit converters and
amplifiers suitable for AO-40.

For SSB/CW use, a modest helix or loop yagi with 10-20 
watts appears to be sufficient.  If you need a power amp,
put it near the antenna, as feedline losses are high!

%%%%%%%%%%%%%%%%%%
%page

Performance Issues

AO-40 S Band is a Weak Signal Mode

	Antenna Gain
	Antenna Polarization, Linear vs Circular is -3dB
	System Noise Figure

Squint Angles

Your signal should be 10dB below the middle beacon!

S1 will be about 10dB Louder than S2

RUDAK 9k6 FSK Packet

%%%%%%%%%%%%%%%%%%
%page

Performance Measurements

Several items were tested on the Agilent Technologies 
noise figure meter at the Dayton Weak Signal Banquet on 
Friday night, with the following results.

	Drake 2880 with typical mods - 6.0dB NF, 23dB gain

	Drake 2880 / DEMI preamp - 1.25dB NF, 37.5dB gain

	Transystems - 1.42dB NF, 28.7dB gain

How about S-band downconverter noise figure and gain 
measurements at the AMSAT Annual Meeting in Atlanta?