Portable Satellite Radio Setup

The ability to operate off-the-grid is a huge advantage when hunting satellites. Coupled with a portable antenna, this battery-operated radio setup can be easily carried to any remote DX location while requiring only very minimal prep time (5 minutes). Simply connect a satellite antenna, turn the radio on,  select the pre-programmed uplink and downlink frequencies, and you are ready to make contact!

The portable satellite radio setup consists of the following:

1. Kenwood TMV71A full-duplex VHF-UHF radio with microphone
2. 12V 8AH lead-acid battery pack with volt meter
3. Sony recorder
4. Headset
5. Other accessories (not shown) such as SWR meter, patch cable, compass, flashlight, notebook, pencil, etc.

Satellite Go-Bag (3).jpg
Everything fits in a small waterproof camera bag, with room to spare for some accessories.

This setup has been used recently in a satellite demo at a local hamfest. Since only 5 watts of power is needed to access the FM satellites, this setup lasts for one week of use (about 50 satellite contacts) in a single charge, perfect for DX-peditions!

Check out more photos of the go-bag below:

In my next post, I will feature the DIY split-boom antenna I use with this setup. To learn how to access satellite repeaters, head directly to Satellite Communications.

Related link: Satellite Go-Box

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

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Satellite Demo at a local Hamfest

CQ satellite! I’ve conducted a live demo of a satellite QSO at District 1 Pakulo 2019, a local hamfest held in Tagaytay, Philippines on May 11, 2019. The demo showcased a satellite repeater’s capability to relay signals and enable two-way communications to any point in the Philippines, as well as nearby countries, using inexpensive ham radio equipment.

To the following stations I’ve worked with during the AO-91 pass: JS6DRQ, DU6DKL, DU2XXA, DU4PGS, 7J1ADJ/JR6, and JA6PL—you are all 5-9, thanks for the contact, 73!

To learn how to access satellite repeaters, click here.

Related links:
About Night Sky in Focus
My Satellites Antenna

To view all posts on amateur radio, click here.

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.

4I1AWN_antenna2
The antenna’s boom may be split in the middle, for easy storage and transport.

Features

1. Very good RX and TX signals. An antenna’s performance is best judge by the receiving end. You can ask other satellite operators I’ve had satellite QSO with to give you a concrete feedback regarding this antenna’s performance. Check out the logs on my QRZ page.
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.

4I1AWN_2019
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. 

DIWATA2 LIVE DEMO CNN
The DIY antenna described on this page was used during the live contact via Diwata 2 satellite’, reported on CNN Philippines

For inquiries, please email: 4i1awn@nightskyinfocus.com

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

Getting Started with Satellite Communications

Welcome to my amateur radio satellite page!

On this page you will find information on how to access amateur radio satellites such as Diwata 2 (PO-101)AO-91AO-92IO-86, and SO-50. By using amateur radio satellites as voice repeater, it is possible to contact fellow satellite operators in nearby countries (such as Japan, Malaysia, Singapore, China, and anywhere in the Philippines) using only a 5W handheld transceiver.

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

Related link: About Night Sky in Focus
To view all posts on amateur radio, click here.
© Anthony Urbano (Manila, Philippines)

Super Moon March 2019

Supermoon with Chocobo
Observing the super moon with our pet rooster

We’ve observed last night’s super moon using a 4-inch f/9 telescope. While it is true that the moon will be closer to Earth during a super moon, the difference in size and brightness compared to a non-super moon is so small and so subtle that it will be very difficult to detect such an almost negligible difference, even for amateur astronomers who regularly observe the moon, and use astronomical equipment such as a telescope.

For previous observations, click here.

For featured photos, click here.
For tutorials on how to get started with astrophotography, click here.
For DIY astronomy projects useful for astrophotography, click here.
To subscribe to this site, click here.

© Anthony Urbano (Manila, Philippines)

 

Apollo 11 Command Module

We’ve visited the Philippine Air Force Aerospace Museum at the Villamor Air Base in Pasay City. The museum features a comprehensive history of the various aircraft and aircraft-related artifacts of the Philippine Air Force, as well as an outdoor exhibit of actual decommissioned aircraft. We were surprised to see a full-size model of the Apollo 11 Command Module in the museum.

Philippine Air Force Aerospace Museum (1)
A scale model of the Apollo 11 Command Module (CM)

To view more photos of this visit, head directly to my other blog.

© Anthony Urbano (Manila, Philippines)

Exclusive Stargazing Event

A stargazing event could easily become the highlight of your exclusive event (such a birthday party, a wedding, a company event, or any other personal event).

supermoon_november_14_2016-1
Looking at the moon through a telescope

The stargazing package may include the following depending on the sky conditions:

1. Moon Astrophotography using the Telescope (1 hour)
2. Basic Stargazing and Finding Constellations (1 hour)
3. Planet Viewing using the Telescope—-Jupiter, Saturn, Mars, and Venus (1 hour)

The details of each part is explained below:

1. Moon Astrophotography

Using the telescope, we will view the moon and take up-close pictures of it (any mobile phone camera can very well do this). Through a telescope, you can clearly see the craters of the moon. Everyone will surely be amazed. You can ask your guests to upload photos of the moon in social media to boost interest. The views and photos your guests will be getting will rival those taken by professional photographers. Moon viewing and photography alone can make your event a unique and truly wonderful experience.


2. Basic Stargazing and Finding Constellations

Your guests will gather around and I will teach them the constellations. We will use a flashlight with red cellophane cover to read maps of the heaven. I will prepare star maps for the specific date you are requesting. These maps will be used by your guests to navigate the night sky. I will then use a powerful laser to point at the stars and constellations as the participants identify them using their maps (this is called star-hopping). I will show them the planets that can be seen with the naked eye. And lastly, I will teach them how to find north without using a compass, but by using the star, Polaris.

3. Planet Viewing using a Powerful Telescope

Several planets are usually visible each night. If visible (it depends on the time of the night and the month of the year), we will use a telescope to look at Jupiter and 4 of its brightest moons, Saturn with its rings, Venus, and Mars.

Important:

As with all stargazing events, if it rains, then we will not see the moon, the stars, and the planets (clouds prevent us from seeing them). This is a very real possibility, thus, must be anticipated. If this happens, I have prepared 2 lectures for your guests, which we can conduct on any covered space (will need a projector and a microphone). The lecture part is just a backup and will not be conducted if the sky is clear.

Let me know if you have any questions. This could be one of the most memorable stargazing events you and your guest could get to experience (and if you receive good feedback, I’d be happy to work with you on a future stargazing events).

To request an exclusive stargazing event, email: aeurbano@up.edu.ph or call 09954997030.

To view our previous observations, click here.

© Anthony Urbano (Manila, Philippines)

 

Call Sign Plate

Each licensed amateur radio operator is awarded with a unique call sign for identification. The National Telecommunications Commission (NTC) requires radio operators to display their call sign in the vicinity of their stations. This call sign plate from the Philippine Amateur Radio Association (PARA) should look nicely when placed beside my amateur radio equipment :)

I have also received a call sign sticker set (for a car’s windshield and radio units) which I will feature in future posts.

No, you can’t use this as vanity car plate (this is a call sign plate, not a vanity car plate)

To learn more about my progress in amateur radio, click here.
© Anthony Urbano (Manila, Philippines)