This is a 1990s Vixen 80 mm f/11 achromatic refractor on an altitude-azimuth mount. I cleaned the lens, repainted the optical tube assembly, and adjusted the mount. This telescope is primarily used for public stargazing events. It is easy to transport, easy to use, and well suited for viewing the moon and planets such as Jupiter and Saturn.
I’ve built a remote shutter switch for my Canon 50D to enable it to take exposures longer than 30 seconds, which is essential in astrophotography. Since the camera already has a battery grip, I just bypassed the battery grip’s shutter button and put an external switch. To make it removable, I used a wire that plugs into a socket hidden neatly in the battery compartment. To watch a demo video, click here.
Mercury, Jupiter, Saturn, and the crescent moon formed a celestial grouping on March 11, 2021, visible to the unaided eye. Also observed was the moon’s earthshine, in which the crescent moon’s darker surface is illuminated not directly by the Sun, but by sunlight reflected off the Earth.
This is an image of the Sun showing the sunspot AR 12192, the largest sunspot of the solar cycle 2010 to 2020. This image was taken at solar maximum when the sun is most active during a cycle. It was imaged in October 2014 in Quezon City using a 4 in f/9 refractor and a Baader ND 5 solar filter. The textured surface of the Sun and a number of sunspots are visible in this photo. Never observe or image the Sun without the proper solar filters.
For a complete list of astrophoto images, click here.
A narrowband filter such as an Oxygen III (OIII) filter inserted along the optical train lets the light from the stars and nebula pass through, but block out everything else, particularly light pollution. This image was taken in Quezon City with a Canon 450D and a 4 inch f/9 refractor, exposed for 30 minutes at ISO 1600, tracked and guided.
For a complete list of astrophoto images, click here.
Smartphones can be used to image the moon by holding it next to the eyepiece of a telescope. For smart phone cameras, a mid-power eyepiece such as a 25 mm eyepiece yields good results. To hold the phone camera steady while taking a photo, a smartphone-to-telescope adapter may be used.
This imaging method is called afocal imaging, in which a camera with its lens is mounted next to another image-forming optical system such as a telescope with an eyepiece or a pair of binoculars.
The Milky Way is most prominent in the sky during months of March to May each year, visible to the unaided eye in the southeastern horizon at around 2 to 3 am. The maps below show how the Milky Way would look like in the Philippine sky at various times of the year.
To learn how to capture the Milky Way, click here.
I’ve built a DIY battery adapter for a Canon 1100D using a 12V power connector, a power supply regulator, and housing of an old battery. The DIY adapter provides power to the DSLR from a DIY field battery for extended use during imaging sessions.
I have built a Morse code straight key using brass plates, small bearings, brass shaft, and some brass screws from power supply binding posts. The key is mounted on the same aluminum plate with my home-brewed electronic keyer with paddles and desk microphone. With this customized straight key, I hope to get a better sense of rythm in sending Morse code.
To watch the straight key in action, along with the electronic keyer with paddles, click here.
I was testing my Morse Code transmitter last night by sending a CQ on 7.102 MHz using various transmit powers ranging from 5 to 10 watts QRP, up to 100 watts full power, using an ICOM 718 and a home-brewed antenna. It appears that 4 stations (one in the Pacific and 3 on the other side of the world—in the US) heard my signal, as reported in the Reverse Beacon Network (an automated system that receives and logs Morse code transmissions).
While this is probably the farthest distance to date that my signal was able to reach, this is just one-way communication. Probably as I improve my antenna, I’d also be able to hear the faint signals coming from the other side of the world.
I’ve built a simple HF (40-meter band) wire antenna with some scrap wires, a length of RG8 cable, PVC pipe as insulator, and some way of securing and making it waterproof. This antenna is intended for receiving (RX only) so I could listen to local voice and Morse code net calls using a Software-Defined Radio (SDR).
The antenna is a dipole with 10 meters of conductor on each side. One conductor is soldered directly to the coax’s outer conductor (braid), while the other conductor is soldered to the coax’s center conductor. I did not use a balun for this antenna, but you may try to use one. Each end of the conductors terminate with a PVC insulator. If you plan on transmitting with a wire antenna, you will need to adjust the length of each conductor for best SWR. I will be using this antenna with an HF radio to send and receive signals in the 40-meter band (7.000 to 7.200 MHz).
To watch a video about this DIY 40-meter antenna, click here.
I have built an ultra-compact DIY iambic Morse code keyer for a dual-paddle key based on the work of PA3HCM. The keyer uses an Arduino Uno and a few components such as a potentiometer for adjusting the words per minute (WPM), a small speaker, some resistors, and LED indicators. I housed the circuitry in a neat enclosure and added some terminals (for signal line-out and an auxiliary connection for a second key). I then attached a dual-paddle key onto the enclosure, making the keyer and key setup a very portable trainer for code practice.
I repurposed my old dash camera (Polaroid N302) as a planetary camera. The lens was removed and replaced with a webcam-to-telescope adapter and then mounted on to a 4 in diameter, 900 mm focal length Sky-Watcher 100ED telescope on a tracking mount.
A 2x Barlow was used to further magnify the image (1800 mm effective focal length). Jupiter’s could bands are visible. To watch a video about this dashcam planetary camera, click here.
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). 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. To watch a video about this homebrewed tracker, click here.
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.
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.
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 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.