How to Make Your First Satellite Contact on SO-50

SO-50 is where most FM satellite operators get started, and for good reason. It's been reliably active since 2002, it works with any dual-band handheld, and passes come regularly throughout the day. That said, there are a few things that catch beginners off guard. This walkthrough covers everything — from predicting the pass to finishing your first contact — so you know exactly what to expect.

What You Need

• A dual-band FM handheld — Baofeng UV-5R, Yaesu FT-60R, or similar. All you need is a radio that can transmit on 2m and receive on 70cm, even if it can only do one at a time. Most budget handhelds, the UV-5R included, are half duplex: they go deaf on the downlink while you're transmitting. That's fine for your first contact. Full duplex (hearing yourself on the downlink while you transmit) is a nice upgrade later, either with a radio that supports it or by listening on a second receiver.
• An antenna — the rubber duck that came with your radio will work for high passes. A handheld yagi or Arrow antenna will work for lower passes and give you much more margin. Start with what you have.
• SO-50 frequencies programmed — uplink 145.850 MHz with 67.0 Hz CTCSS, downlink 436.795 MHz.

Step 1 — Find a Good Pass

Open Ham Sat Tracker, enter your location, and look for an SO-50 pass with maximum elevation above 30°. Higher passes give you more time in range and a stronger signal. Your first attempt will go much better at 45° or higher than trying to chase a 10° scraper across the horizon.

Note down the pass details: AOS time, AOS azimuth (which compass direction the satellite rises from), maximum elevation, and LOS azimuth (where it sets). You'll use these to know where to point your antenna.

Ham Sat Tracker also shows Doppler-corrected frequencies at AOS, TCA (closest approach), and LOS. Write these down or keep the app open during the pass — you'll need to adjust your transmit frequency as the satellite moves.

Step 2 — Program Your Radio

You need two memory channels minimum:

• Channel 1 (AOS): Transmit 145.870 MHz with 67.0 Hz CTCSS / Receive 436.810 MHz
• Channel 2 (TCA): Transmit 145.850 MHz with 67.0 Hz CTCSS / Receive 436.795 MHz
• Channel 3 (LOS): Transmit 145.830 MHz with 67.0 Hz CTCSS / Receive 436.780 MHz

These are approximate Doppler values for a typical pass. Ham Sat Tracker shows the exact values for your specific pass — use those. The key point is that you transmit slightly high at AOS (satellite approaching, frequencies compress), on nominal at TCA, and slightly low at LOS (satellite receding, frequencies expand).

The 67.0 Hz CTCSS tone on the uplink is mandatory. Without it SO-50's squelch won't open and it won't hear you. Double-check that your radio is actually sending the tone — some radios need it enabled in a separate menu beyond just having the value entered.

Step 3 — Wake the Satellite

SO-50 has a 10-minute activity timer. If nobody has used it recently, it goes to sleep to conserve power. Before your main transmission, send a brief one-second carrier with 74.4 Hz CTCSS to wake it up. You'll know it's active when you hear the downlink squelch tail or other stations.

If you can already hear activity on 436.795 MHz before the pass starts, the satellite is already awake and you can skip the activation step.

Step 4 — The Pass Itself

A few minutes before AOS, go outside, face the AOS azimuth, and get ready. When AOS arrives:

1. Switch to your AOS frequency pair and listen. You may hear other stations or the satellite's squelch tail if it's active.
2. Send the 74.4 Hz activation tone if needed.
3. Listen for the downlink to confirm SO-50 is in range. You'll hear a clear FM signal — possibly other operators already working it.
4. When there's a gap, transmit: "CQ satellite, CQ satellite, this is [your callsign], [your callsign]." Keep it brief — passes are short and there are usually other operators waiting.
5. Listen on the downlink for a response. If someone comes back to you, give a signal report and your grid square: "VE3AKK, you're 59, grid FN15, back to you."
6. As the satellite rises toward TCA, switch to your TCA frequency pair. As it descends toward LOS, switch to your LOS pair.

Point your antenna at the satellite throughout the pass. It rises from the AOS azimuth, arcs across the sky to the maximum elevation point, then descends to the LOS azimuth. Watch the elevation — at TCA you'll be tilting the antenna up toward the sky; near AOS and LOS it's closer to the horizon.

What If Nobody Responds?

It happens, especially on your first few attempts. A few possibilities: the satellite was in sleep mode and you missed the activation, your CTCSS tone wasn't transmitting, your Doppler correction was off, or there simply weren't other operators on that particular pass. Try again on the next pass. Once you can hear other stations through the downlink, you know your setup is working and it's just a matter of timing a transmission between others.

Even hearing the satellite — picking up its downlink signal or hearing other operators — is a milestone worth noting. It means your receive setup is working and you're genuinely in range.

Logging the Contact

A valid SO-50 contact is logged like any other — callsign, date/time (UTC), frequency (145.850 for the uplink), mode (FM), and signal report. Include the grid square exchange if you made one. Many satellite operators also log the satellite name and the pass maximum elevation.

For awards purposes, satellite contacts count toward VUCC (VHF/UHF Century Club) grid square totals, which is one of the reasons grid square exchanges are so common on the birds.

Your Second Pass

Once you've made one contact, the next goal is consistency — working SO-50 on passes of different elevations, at different times of day, with different operators. The technique becomes automatic quickly. Within a few sessions you'll be working passes confidently enough to start exploring AO-91, and eventually the SSB birds.

73 de VE3AKK