Amateur Satellites Pt. II

How to work the easy sats on a budget.

In the Presentation…

• Discuss how to set up a satellite station.

• Discuss the new Echo sat (AO-51)

• Discuss WX sats, particularly NOAA 18

Simple Satellite Station

• Voice satellites (repeaters in space)– Dual Band Handheld– Half-wave whip or handheld Yagi

• Voice and Data satellites– Dual Band Radio– Vertical antenna (Yagi in optimum setup)– Computer with soundcard– Free software (AGWPE and UISS)– Interface

Voice Setup with Handheld

• Program all frequencies into HT taking into account Doppler effect– Ex: Uplink 1: 145.845 Downlink 1: 436.805 Uplink 2: 145.850 Downlink 2: 436.800

• Change frequency as the satellite moves overhead. Start with Uplink 1 when the satellite is low, TX and listen on Downlink 1. Do this to U5/D5 when the satellite is about to dip below the horizon.

Voice Setup with Handheld

• To improve reception, tilt your whip antenna parallel to the satellite’s path. You must know where the satellite is in the sky at a given time.

• Or use a handheld Yagi antenna and point it directly at the satellite. Again, you must know where the satellite is. This can be a trial and error process.

Voice and Data Setup

• Program Uplink and Downlink frequencies. In the case of the ISS you may use an odd offset setting. Doppler shift is not as important because both U/D frequencies are in the 2m band.

• Connect TNC or soundcard to radio. The ISS operates as a BBS, APRS node, and digipeater. To digipeat, use SSID RS0ISS-3.

ECHO (AO-51)

• Latest AMSAT project. Debuted last summer.

• Allows you to work data up to 38.4 kb/s and voice. Better range than most of the sats currently operating.

• Also serves as an excellent voice repeater with a tone of 67 Hz.

ECHO’s modes

• Analog Uplink: 145.920 MHz FM (PL - 67Hz) 145.880 MHz FM (QRP, No PL) 1268.700 MHz FM (PL - 67Hz)

• Analog Downlink: 435.300 MHz FM 2401.200 MHz FM

• PSK-31 Uplink 28.140 MHz USB

• Digital Uplink: 145.860 MHz 9600 bps, AX.25 1268.700 MHz 9600 bps AX.25

• Digital Downlink: 435.150 MHz 9600 bps, AX.25 2401.200 MHz 38,400 bps, AX.25

SO-50

• Another great satellite for beginners.

• Voice repeater: Uplink 145.850 MHz Downlink 436.795 MHz

• Requires a 67 Hz tone.

• Workable with an HT.

Oscar 27 (AO-27)

• Not operational after battery charging. Technicians are working to get the sat operational.

• Voice Repeater: Uplink 145.850 MHz

Downlink 436.800 MHz

• A nice sat to try for first contact. It can be worked with an HT.

Future Projects

• SSETI Express to be launched later this month. Will give a prize to the amateur who provides the ESA the most telemetry from the satellite. Scheduled for launch this month.

• AMSAT Phase 3E will be a satellite with a wide range of modes and frequencies. Launch scheduled for late this year or early next year.

• PCSat 2 will give amateurs the opportunity to operate packet or PSK 31 from space. It will be attached to the ISS and is scheduled to be installed during the Discovery mission due to launch this week.

NOAA WX SATS

• Since my last talk, a new polar orbiting satellite, NOAA 18, was added to NOAA’s current satellite constellation.

• NOAA 18 transmits on 137.9125 MHz.• Transmissions can be monitored easily

with a scanner or a specialty receiver. The receiver is connected to the soundcard. No other hardware is required.

NOAA WX SATS

• Other APT frequencies: 137.500 and 137.620 MHz.

• Satellites scan the surface in IR and visible wavelengths as they pass overhead.

• There are currently four active APT satellites that make two good passes each day.

A typical NOAA 18 image

THE END

• Questions?• Contact www.amsat.org for more info.• Useful software may be downloaded for

free at the following:• WXtoImg at www.wxtoimg.com• UISS at

http://users.belgacom.net/hamradio/uiss.htm

• AGWPE at http://www.raag.org/sv2agw/inst.htm