Your First Satellite Contact

An FM amateur satellite works much like a repeater in orbit. It hears you on one band and retransmits on another, and because it is hundreds of miles up, everyone under its footprint can hear it at once. A pass lasts only a few minutes, but in that time you can talk with stations far beyond the reach of any hilltop repeater.

You do not need a tower, a rotator or a big station to get started. Many hams make their first satellite contact standing in a backyard with a handheld radio in one hand and a small antenna in the other. Here is how to do it.

Yes, a Technician Can Do This

Under 47 CFR 97.301(a), Technicians have the same privileges as higher classes on the VHF and UHF bands, including all of 2 meters (144 to 148 MHz) and 70 centimeters (420 to 450 MHz) in the Americas. Section 97.209 says any amateur station may be an Earth station, meaning one that talks to a satellite, within the privileges of the operator’s license class.

The rules set aside 144 to 146 MHz and 435 to 438 MHz, among other segments, for satellite work, and the FM satellites use those two ranges. So a Technician holds every privilege needed. Our privileges tool and Part 97 in Plain English page have the details.

What You Need

• A Dual-Band Radio: it must transmit on one band and receive on the other. A radio that can listen while it transmits is a big help, as explained below.
• A Handheld Yagi: a small beam with elements for both 2 meters and 70 centimeters. The stock rubber antenna on a handheld is usually not enough.
• Earphones: they keep the downlink from feeding back into your microphone and make weak signals easier to hear outdoors.
• A Recorder: a phone voice recorder lets you play the pass back later and log calls you missed in the moment.
• Your Grid Square: the short location code everyone trades on satellites. Our grid square tool will find yours.

A word on safety: a handheld Yagi has thin elements at eye height, so mind people and pets around you as you swing it. While you transmit, keep the elements away from your own face and do not point the beam at anyone nearby.

Finding a Pass

Satellites come and go, so first check the AMSAT satellite status page, where operators report which satellites they have heard and when. That shows you which FM satellites are working now. Then look up each one’s uplink and downlink frequencies on AMSAT’s FM satellites page, and read the notes. Some need a CTCSS tone on the uplink, some run only on a schedule, and some ask you to stay off at certain times to protect their batteries.

Next, use AMSAT’s online pass predictions. Enter your latitude and longitude, or let it work them out from your grid square, choose a satellite, and it lists upcoming passes over your location. For a first try, pick a pass that climbs high in the sky, since high passes last longer and give stronger signals than ones that barely clear the horizon. Note the time it rises, the direction it comes from, and where it sets.

Uplink, Downlink and Doppler

The uplink is the frequency you transmit on, and the downlink is the one you listen to. On FM satellites, one is on 2 meters and the other is on 70 centimeters. Program both into your radio as a split channel or a pair of memories before the pass.

Because the satellite moves so fast, its signal shifts in frequency during the pass. This is Doppler shift, the same effect that changes the pitch of a passing siren. As the satellite approaches, you hear it a little high; at its closest point it is near the listed frequency; as it leaves, you hear it a little low. The shift grows with frequency, so the 70 centimeter side moves about three times as much as the 2 meter side.

The usual approach is to correct only the 70 centimeter side and leave the 2 meter side alone. Many operators store a few memories for the 70 centimeter frequency, set a little high, on frequency and a little low, and step through them as the pass goes by. If the audio gets scratchy or distorted, move to the next memory.

Full Duplex or Half Duplex

A full duplex station can hear the downlink while it transmits. That is a real advantage, because you hear your own voice come back from the satellite. You know at once whether you are getting in, and you never talk over someone else without realizing it. Some dual-band radios can do this, and some operators use two radios, one to transmit and one to listen.

Most handhelds are half duplex: the receiver goes quiet while you talk. You can still make contacts that way. Just listen carefully, make sure you are hearing the satellite well before you call, and keep each transmission short so you are back to listening quickly.

Making the Contact

1. Be outside a few minutes before the pass, with the antenna pointed where the satellite will rise.
2. Listen first. Follow the satellite across the sky with the antenna, and twist the antenna slowly if the signal fades, since the best angle changes during a pass.
3. When you hear a gap, give your callsign and grid square once, phonetically, and listen.
4. If someone answers, confirm their callsign and grid, give yours, and thank them. That is the whole contact.
5. Step back and let others use the rest of the pass.

An FM satellite is a single channel shared by everyone in view, and a busy pass can sound like a crowded room. Long chats and repeated CQ calls are out of place. One or two contacts per pass is plenty, especially on your first few tries.

After the Pass

Play back your recording and log each contact with the time in UTC, the callsign, the grid square and the satellite. If you want confirmations, our article on QSL cards and LoTW explains how. The AMSAT status page also invites you to report what you heard, which helps the next newcomer.

If your first pass is all noise, you are in good company. Try a few passes just listening, until you can follow the satellite and keep the signal clear. Once you can hear it well, your first contact is usually only a pass or two away.