N3VBJ's Satellite Information Web Page 

Putting Together Your Receiving System

 

An optimum radio amateur satellite receiving system consists of antennas, rotor, preamplifier, receiver, and a modem for the digital modes. The receiver is usually the most expensive piece of equipment, so let's start by analyzing the characteristics an ideal receiver should have. The table lists types of receivers and all of the satellites that can be received with each receiver.

The receiver doesn't have to have all of the above characteristics, but the more it has, the more modes and more data you'll be able to copy.

Table 1. Receiver Types and the Satellites You Can Work With Each
10-meter SSB Receiver RS-10/11, RS-12/13 and RS-15 using Voice and CW
2-meter SSB Receiver AO-13, AO-10 using Voice, CW, RTTY and SSTV with 400 BPS PSK modem: AO-13 telemetry with 1200 BPS Bell 202 modem: UO-1 1 data and telemetry
2-meter FM Receiver MIR, DOVE, SAREX using Voice with 1200, BPS AFSK AX.25 modem: DOVE, Mir, SAREX and AO-27 digital data
70cm SSB Receiver FO-20 Voice and CW; with 1200 BPS PSK AX.25 modem: AO-16, WO-18 and LO-19 digital mail and experimental data
70cm FM Receiver (with 430-440 MHz coverage) AO-27 in digital voice mode; with 9600 BPS FSK modem: UO-22, KO-23 and KO-25
2.4 GHz SSB Receiver or Receive Converter AO-13 using Voice and CW

Preamplifier

Adding a preamplifier at the bottom of your antenna is an easy and cost effective way of improving your satellite reception. As the received frequency increases, so do the losses in signal strength caused by the coax cable connecting the antenna with your receiver. A preamp placed just underneath the antenna will amplify the signal received making up for the losses induced by the coax cable.

Antennas

There are several types of antennas that may be used to work with amateur satellites, such as turnstiles, eggbeaters, helixes. The most used one for frequencies below 1.2GHz is the cross Yagi, with both horizontal and vertical elements. To work digital satellites a 12-14dB gain antenna is preferred, for FO-20 a 14dB gain is fine, and for the AO-10 and AO-13 satellites the longer the antenna the better…

A rotor capable of azimuth/elevation movements is also a desirable thing. You are then capable of aiming the antennas at the satellite as it passes overhead.

Currently GREpredic Software livetime tracking supports the Live Tracking. Download GPREdict software and start tracking today. Ham radio deluxe can control your rig and Rotor thru a Serial interface card which is pluged into your computer. This acts as an interface between the rotor and the computer. Using this can automatically control the rotors and move the antennas for you, tracking in real time any satellites you select.

Modems

As you can see from Table 1, each digital satellite mode usually requires a different kind of modem ($100-$150). If however you buy a DSP modem you'll pay more, but you'll have all the modes in one box.

What do Amateur Satellites Transmit?

The analog satellites have voice and CW (Morse code) signals, as well as occasional RTTY (Radio TeleType) and SSTV (Slow Scan Television) signals. All satellites also transmit telemetry signals, such as how much power the satellite is using to transmit, the satellite's temperature, solar cell current and many other interesting things. This telemetry is transmitted as AX.25 (packet data). Some data is also sent using ASCII, CW or RTTY.

Receiving satellite pictures from weather satellites

There are two kinds of weather satellites. They can either be geostationary or spinning in polar orbits around the earth. Geostationary satellites are satellites 36000km above our heads, whose position in space relative to us on earth never changes. Once you point your antenna at them you won't have to move it again. The European Meteosat satellite and the American Goes satellites are geostationary weather satellites. Meteosat transmits continuously on 1.69GHz, and can be received using small satellite dish, a receive converter which converts the 1.67GHz into 137MHz, a receiver capable of receiving 137MHz with a 30KHz bandwidth, a simple interface to convert the receiver's analog data into digital data which is fed into the computer through the serial port. Shareware software like JVFAX 7.0 will then decode these signals and give you a photo on screen just like those in the weather forecasts you see on TV. The dish runs for $50-$100, the receive converter is about $150-$200, the receiver ranges from $100 to $500, and the software is shareware.

Interfaces

There are also polar weather satellites. Among these are the Russian Meteors and the American Noaas. These satellites have very low orbits (~1000Km) compared to those of geostationary satellites (~36000Km). Their photos are thus a lot more detailed, but will cover only a small portion of the earth. They transmit at around 137MHz, and can be received using a couple of simple round dipole antennas. The equipment needed is the same as for the Meteosat, with the difference in antennas and the unnecessary receive converter.

Tracking Satellites With Your Bare Eyes

It is possible to watch satellites with your bare eyes, given the right conditions. Using LogSat just select a very low orbiting satellite, as could be the Russian space station MIR, or the space shuttle during one of its flights, see when it passes overhead, go outside and with a bit of luck you should be able to spot it. The key is choosing a good time of the day. The best chance of seeing one is a little after sunset, when you're in the dark, but the satellite is still illuminated by the sun, which will reflect onto the satellite body, allowing you to see it.

 

Satellite Tracking Software and Keperalian Elements

AMSAT  North America http://www.amsat.org/amsat-new/index.php is a great wealth of information and resources.

Live Satillite informationLink to amsat.org

Ham Radio Deluxe provides RIG control and tracking Ham Radio Deluxe Download Page

 
 

 

 

Displayed here are the recommended frequency programs for some of the more popular FM Amateur Radio Satellites. Included with each frequency plan, is the web address / link to the particular satellites information page. All of these satellites have varied schedules as to when and what mode they will be in operation. It’s always good to check these schedules out before you go out to “work the birds!”

See other resources at the bottom of the page.

Have Fun!

 

AO-51 Satellite 
http://www.amsat.org/amsat-new/echo/CTNews.php

SO-50 Satellite
http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=4&retURL=/satellites/status.php


What’s this thing with the 74.4 Hz tone?  That actually turns the radios in the satellite on!  In the rare event that SO-50 comes over the horizon, and no traffic is heard, transmit this tone for about 2 seconds.  This will turn the radios on.  If there is no traffic detected for ten minutes, the radios will shut off.  This saves battery power.

AO-27 Satellite
http://www.ao27.org/AO27/index.shtml

SO-67 Satellite
http://www.amsatsa.org.za/

HO-68 Satellite (Formerly Known as XW-1)
http://www.camsat.cn/

International Space Station (ARISS)
http://www.issfanclub.com/

Talk Through the International Space Station Like a Satellite Repeater:

Talk To the International Space Station Astronauts:

 

 

Here is a guide I use as a reference you can save a copy and refer to it. Every Satillite as of December 2015.

NASA Satellite Frequency Guide PDF

 

 

Back to W3PGA Club Web Page

 

 

 

 Last Updated December 2015 (C) N3VBJ

Web Hosting
This page Created With Hotdog Professional 5 Sausage.bmp - 13678 Bytes