DIY Satellite Antenna

I have recently finished preparing the plans for making a DIY dual-band satellite antenna.

Satellite Antenna
DIY Satellite Antenna. To view larger, click here.

To learn how to build one and get started with satellite communications, click here.

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


Satellite QSL Card from BG5UTE (China)

I have received these cards from BG5UTE (China), for our contact on various satellites on April and May, 2019. Shi sent me a QSL-card confirming each of our first contacts in AO-91, AO-92, SO-50, and PO-101 (DIWATA 2). The cards’ cover features a photo of an Iridium satellite flare taken by BG5UTE himself! Thanks for these cards, I’ll be sending mine soon!

For more posts about QSL cards I’ve received from fellow hams, click here.

Interested in a paper QSL-card exchange? Catch me on one of the satellites, then send me an email:

To learn how to access satellite repeaters, head directly to Satellite Communications.

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

STAMINA 4 SPACE awards DIWATA 2 Testers

Prior to the service announcement, a small group of volunteer amateur radio operators worked with the engineers from STAMINA4SPACE Program (formerly named as the PHL-MicroSat Program) to test the full capabilities of DIWATA2’s Amateur Radio Unit. The scope involves testing the receiving (RX) and transmitting (TX) capabilities of the satellite both for voice mode and data mode. It also includes determining the kinds of antennas, the clarity of voice communication, and how much power is actually needed to access the satellite.

Plaques of appreciation were awarded to the first 10 stations to ever access DIWATA 2, and certificates for those involved in the testing efforts.

First 10 Stations to make a successful QSO via DIWATA2 Satellite

  1. Jharwin Barozzo, DV2JB (Phillippines), formerly DV2JHA
  2. Anthony Guiller Urbano, DU1AU (Philippines), formerly 4I1AWN
  3. Joseph Petruff, 7J1ADJ/JR6 (Japan)
  4. Afer Shi, BG5UTE (China)
  5. JS6DRQ (Japan)
  6. Iji Yoshitomo, JA6PL (Japan)
  7. Brian Santos, DU1MS (Philippines)
  8. JR6DI (Japan)
  9. Hong Liu, BH4ESB (China)
  10. Stanley Sumping Anak Albert Bejie, 9W8DNX (Malaysia)

For assisting with the testing efforts and achieving one of the firsts QSOs via DIWATA2, special awards were given to

  • Percival Padilla, DV1XWK (Philippines)
  • Lee Castor Canono, D8BVK (Philippines)
  • Veronica Catherine Anak Nohan (9W8VWW, Malaysia)

The awards were given on April 26, 2019, at the Electrical and Electronics Engineering Institute Bldg., University of the Philippines, Diliman, Quezon City, through AMSAT Philippines president Atty. Eduardo Victor Valdez, PHL-50 project leader Dr. Marc Caesar Talampas, and  STAMINA4SPACE program leader Dr. Joel Joseph Marciano Jr.

The testing team will continue to assist the STAMINA4SPACE program in monitoring the status of DIWATA2’s Amateur Radio Unit.

To learn how to access the DIWATA2 satellite, head directly to Satellite Communications.

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

Accessing Satellites at Low Elevation

In a recent test I’ve conducted with my portable satellite radio setup, I’ve successfully accessed the following satellites even at elevations of only 1 to 2° (very near the horizon!): AO-91, AO-92, IO-86, SO-50, and PO-101 (DIWATA2).

Satellite’s Elevation

A satellite on the horizon is described to have an elevation of 0° (degree) and a satellite directly overhead has an elevation of 90°. A pass may have an elevation anywhere from 0 to 90°.

Low Elevation Pass Satellites
Using a DIY antenna and a portable radio setup to access satellites that are very near the horizon

Establishing Contact

While there are many factors leading to a successful low-elevation contact, the following appears to have the greatest impact:

1. Use of a well-tuned and very directional hi-gain antenna
2. Proper pointing of antennas to satellites (use a smartphone)
3. Correct polarization of antenna elements (twist until you get the best signal)
4. Use hi-power when necessary (10W)

Have you done this test lately? How low an elevation can you access the satellites? If you want to make contact with distant stations via satellite, the only way to do that would be to access satellites when they are very low in the horizon.

To learn how to access satellite repeaters, head directly to Satellite Communications.

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


Satellite Demo on CNN Philippines

The live DIWATA 2 satellite demo on May 17, 2019 was covered by several major news outlet including CNN Philippines. Below is a screenshot from a CNN report aired on national TV.

4I1AWN performing a live contact via Diwata 2 satellite’s amateur radio unit, reported on CNN Philippines (May 17, 2019)

To watch CNN’s report, click here.

Related link: Watch DIWATA 2 Live Satellite Demo

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

My Satellite Antenna

Download: Satellite Antenna Plans

Satellite Antenna
DIY Satellite Antenna. To view larger, click here.

My satellite antenna is a Moxon-Yagi-Uda dual band VHF-UHF antenna with a single feed point (connects directly to the radio, no duplexer needed), based on the original design of LY3LP. This allows using a full duplex radio to simultaneously transmit in one band and receive in the other. Properly tuned, this antenna has an SWR (Standing Wave Ratio) of 1.0:1 in VHF and 1.1:1 in UHF.

The antenna’s boom may be split in the middle, for easy storage and transport.


1. Very good RX and TX signals. Check out the logs on my QRZ page or hear the audio recording as received by this antenna in this video prepared by DV2JHA.
2. Easy to build. This antenna build is intended to be very easy to replicate. Very few tools and materials needed to build one. No special parts needed. Anyone can build it.
3. Elegant design. Because it only has one feed point, you only need one dual-band VHF-UHF radio to use this antenna (instead of using two different radios and feed points for each band, thereby eliminating the need for a duplexer). The coaxial cable from the radio connects directly to the antenna (no baluns). To maximize the full capability of this antenna, use it with a radio with full-duplex capability.
4. Easy to tune. You only need to adjust the gap between the Moxon (VHF) driven element, and the Yagi-Uda (UHF) driven element to achieve perfect SWR. If you wish to move the center frequency (the frequency with the lowest SWR), adjust the length of the driven elements.
5. Lightweight. You will begin to appreciate this once you compare it with other antenna designs. Heavy antennas are not particularly useful for hand-held satellite work.
6. Portable. With the split-boom feature, you can easily store and transport this antenna. If needed, you can always disassemble and collapse everything into a very small package.
7. Durable. This antenna design is built to last a lifetime of satellite work.
8. Low-cost. How much does a commercial satellite antenna cost? To build this antenna, I spent an equivalent of 5 USD.

This antenna has been fully tested to work with satellites such as AO-91, AO-92, SO-50, IO-86, and PO-101 (Diwata 2). To build your own satellite antenna, kindly refer to the antenna plans below.

To view at full resolution, click here. Adapted from the original design by LY3LP. This particular version with a number of modifications is created by 4I1AWN. It uses 3 mm copper tubing elements.

To see this antenna in action (a recorded ‘live’ satellite demo), head directly to Satellite Communications. To view the portable radio setup I use with this antenna, head directly to Portable Radio Setup. 

The DIY antenna described on this page was used during the live contact via Diwata 2 satellite’, reported on CNN Philippines

Download: Satellite Antenna Plans
For inquiries, please email:

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

Scheduled SSTV Transmissions (February 2019)

The International Space Station (ISS) is scheduled to transmit Slow Scan Television (SSTV) images this weekend, as reported in the ARISS-SSTV webpage.

Start: February 15, 8:45 UTC (February 15, 4:45 pm, Philippine Standard Time)
End: February 17, 17:25 UTC (February 18, 1:25 am, Philippine Standard Time)

All ISS passes within this period present opportunities to receive the SSTV transmissions. You can use an app called ISS Detector (for smart phones) or visit the website Heavens-Above to view upcoming passes (do not forget to set the apps to show all passes, and not just the visible ones).

To receive and decode the transmissions, you need a radio receiver capable of tuning to 145.800 MHz and a decoder app such as Robot 36.

ISS pass details (Philippine Standard Time) generated using Heavens Above

Related link: Receiving SSTV Transmissions from the International Space Station

To learn more about receiving SSTV images from the ISS, click here.
To subscribe to this site, click here.
© Anthony Urbano (Manila, Philippines)