SSTV from the International Space Station (ISS)

The International Space Station (ISS) recently conducted a week-long radio transmissions test by sending encoded signals in Slow Scan Television (SSTV) image transmission format to be decoded by anyone with the proper amateur radio equipment tuned at 145.8 MHz and an SSTV decoder app such as Robot 36.

Certificates are given to stations who have successfully decoded SSTV images from ISS

SSTV images are sent and decoded line by line, much like how scanners and printers work.

Image received from the ISS

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIY SARCNET Satellite Tracker

I have built a DIY satellite tracker based on the SARCNET project. It is a simple Arduino-based motorized azimuth and elevation rotator that uses DC motors to move the antenna, and gets position feedback using an accelerometer and compass.

The tracker receives satellite’s azimuth and elevation info using the tracking software Gpredict. Hamlib is then used to establish a link between the computer and Arduino through USB connection via EasyComm II protocol.

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

Receiving NOAA Satellite Image

NOAA satellites transmit weather images in APT format at 137 MHz which may be received using just a VHF antenna, a software-defined radio (SDR), and a decoder such as Wxtoimg running on a laptop.

My first weather satellite image decoded on December 3, 2020, as NOAA 18 passes over the Philippines.

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

PSAT2 Satellite SSTV Images

PSAT2 transmits SSTV images at 435.360 MHz (UHF) which may be received using just a DIY Moxon-Yagi satellite antenna, a UHF radio, and a decoder such as Robot 36 running on a smartphone (Android). Here is an image decoded in May 2020, as PSAT2 passes over the Philippines.

SSTV image from PSAT2

SSTV transmission by PSAT2 is active only at daytime. Doppler-effect compensation is necessary to properly receive the transmission. Tune the radio at 435.370 to 435.350 MHz from start to end of the pass. You may decode up to two SSTV images per pass. To watch a a demo video click here.

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIY Satellite Antenna DU1AU

A satellite antenna can be made from 3 mm copper or aluminum elements, PVC boom, and some parts you may already have at home. This antenna has been tested to work with the Philippine Oscar (PO)-101 satellite Diwata 2.

DIY Satellite Antenna

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIY SATNOGS Satellite Tracker

I’ve recently finished building a satellite traker based on SATNOGS satellite tracker. The automated tracker uses an Arduino to control a pair of stepper motors that move two cross-yagi antennas (VHF and UHF).

DIY SATNOGS satellite tracker

The Arduino receives satellite’s azimuth and elevation info using the tracking software Gpredict. Hamlib is then used to establish a link between the computer and Arduino through USB connection via EasyComm III protocol. The tracker uses two A4988 stepper motor driver, and two geared stepper motors. A weatherproof metal box is used as a case, and rubber seals prevent water from entering.

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

Satellite Demo with Phil Navy

I was invited to conduct a live satellite demo at the Pascual Ledesma Naval Station in Cavite, Philippines. We’ve accessed DIWATA2 (PO-101) and had successful contact with JA6PL (Japan), DV2JHA (Pangasinan), and DU1ELT (Cotabato).

Naval Sea Systems Command
Live demonstration of a satellite contact

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIY Portable Satellite Radio Setup

This battery-operated radio setup can be easily carried to any remote location. Connect a satellite antenna, turn the radio on,  select the pre-programmed uplink and downlink frequencies, and you are ready to make contact!

A portable satellite radio setup

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIY Arduino TNC

I have finished building and testing a DIY Terminal Node Controller (TNC). With a TNC, any radio may encode and decode signals in the Automatic Packet Reporting System (APRS) format. This TNC is based on the home-brewed TNC project by VK3DAN.

Arduino-based TNC

The TNC requires a smart phone with APRSdroid connected via bluetooth. It taps directly to a radio through the dedicated audio line-in and line-out ports. I’ve tested this TNC to work with the International Space Station’s (ISS) digipeater at 145.825 MHz, using the digipath: ARISS.

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Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines

DIWATA 2 Satellite Test

In March 2018, I worked with the STAMINA4SPACE to test the DIWATA2’s Amateur Radio Unit (ARU). The task involves testing the receiving and transmitting capabilities of the satellite’s on-board amateur radio equipment.

To view all posts about amateur radio, click here.

Night Sky in Focus | Astronomy and Amateur Radio
© Anthony Urbano | Manila, Philippines