DIY Pier Extension for EQ Mount

I have built a DIY pier extension to allow my DIY go-to telescope to move without hitting the tripod legs. It consists of three 12-inch L-bars (which I later shortened to 7.5 inches, after measuring the minimum clearance required) that lift the tripod head. I repurposed a tripod head from an old and unused tripod to serve as the base where the L-bars and the tripod legs connect to. The pier extension allows unattended imaging without the risk of damage to the mount or telescope.

DIY Pier Extension

To watch a video of the telescope performing a successful meridian flip without hitting the tripod legs, click here.

Related link: Converting the Vixen Great Polaris mount into a Go-to mount

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

DIY Telescope Controller | OnStep

I have built a controller for my Vixen Great Polaris mount using the OnStep go-to telescope controller developed by Howard Dutton. I used an Arduino Mega 2560 as the main controller board, a pair of LV8729 stepper motor driver, and an HC-05 bluetooth module (which connects to the OnStep Android app).

I also built a ESP32 Smart Hand Controller (SHC) developed by Charles Lemaire, Howard Dutton, and other contributors, which was derived from TeenAstro . I used an ESP32 module, an OLED display, and a button array for the SHC that connects to the same serial communication lines (Rx and TX pins) used by the HC-05 bluetooth module (I use a toggle switch to select between the HC-05 Bluetooth module for the Android controller and the Smart Hand Controller with ESP32 module) .

OnStep Telescope Controller

I used a pair of 200-step-per-revolution stepper motors paired with 60-teeth and 16-teeth pulley and belt drive system to motorize the Vixen Great Polaris mount with 144:1 worm drive. In this configuration, the total steps are 200 steps * 60/16 reduction * 144/1 teeth worm drive = 108,000 steps per 360 degrees at full stepping. Actual testing showed that accurate tracking is possible at 1/64 microsteps (60 second unguided exposures at 900 mm focal length) . This brings the total steps per revolution to 6, 912, 000 per 360 degrees, or 19,200 per degree (you need to configure this in the OnStep code).

The OnStep telescope controller can be connected to NINA to enable automatic slewing to targets and use plate-solving to validate and refine its pointing accuracy. It also connects with Stellarium to display real-time the telescope’s current position.

Unguided 60 sec exposures at 900 mm with an OnStep-controlled mount, Dumbbell Nebula (1 hour)

OnStep will have very accurate pointing and tracking even with just one-star alignment, if properly polar-aligned.

OnStep Telescope Controller


Related links:
Trifid Nebula imaged with the OnStep DIY Go-to Controller
OnStep Main Page
Smart Hand Controller Main Page
Schematic Diagram OnStep Main Board and Smart Hand Controller

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

Vixen R114 on Great Polaris Mount

I have recently acquired a Vixen R114 Newtonian reflector (114 mm aperture, 900 mm focal length at f/7.9) on a Great Polaris equatorial mount. The mount does not have motors, but I have converted it into a fully-automated go-to and tracking mount capable of unguided exposures of at least 60 seconds (field-tested without guiding).

Vixen R114 on Great Polaris Mount

The reflector has a very good primary and secondary mirror cells which allowed precise collimation and prevent strained optics. The stock focuser is a 0.965 in barrel which I modified and converted to the 1.25 in standard. The rack-and-pinion focusing mechanism is very precise and sturdy enough to hold an ASI 533 astronomy camera even without using the focuser lock. It comes with a 6 x 30 mm finder which is adequate for pointing at bright targets.

Trifid Nebula M20, 1.7 hours exposure

The Vixen R114 on Great Polaris equatorial mount now serves as my long focal length telescope both for visual observation and imaging.

Related link: Converting the Vixen Great Polaris mount into a Go-to mount

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

Laser Pointer as Finder

I have installed a laser pointer to my telescope as a tool for locating objects. The laser pointer is mounted on a finder scope holder with collimation screws to enable alignment with the telescope. It has a toggle switch that allows the laser to be turned on and off.

Using laser pointer as a finder

To find an object such as a galaxy or a nebula, I turn the laser on and point the telescope to the target’s approximate location as indicated in a star map. If the target is too dim and there are no bright stars in the vicinity, I just use a pair of binoculars to spot the target and then slew the telescope manually to the target. The laser allows me to know precisely where the telescope is pointed at, and then use the laser to guide the telescope to the target. Observe safety precautions when using laser pointers.

To view posts on DIY projects and astronomical equipment, click here.

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


DIY 40 m, 20 m, 15 m HF Dipole

I have built a multi-band DIY fan-dipole antenna for 40-meter, 20-meter, and 15-meter HF bands. A fan dipole consists of several dipoles fed at a common feed point, through an optional 1:1 balun. I have tested this antenna and I have confirmed QSOs from Philippines to Brazil (other side of the world from the Philippines, via FT8 on 15 meters) and Philippines to Sydney, Australia (SSB voice on 15 meters).

A fan dipole may be designed to operate on a number of bands simply by adding new elements to an already existing dipole, but adding new elements may change the tuning of the already tuned dipoles, making it difficult to build one that is designed to operate on too many bands. In this particular antenna build, I combined three dipoles—for 40 meters, 20 meters, and 15 meters—to form a multi-band fan dipole on a single feedline.

DIY Fan-Dipole Antenna


The driven elements are 12-gauge insulated wires, center-fed (split in the middle). I used a 7 meter RG8 coaxial cable feedline with 1:1 BU-50 balun. The feed point is housed in a weatherproof metal enclosure that has been placed on an elevated concrete ledge. I used non-metallic material to raise and anchor the ends of the wires, such as nylon rope.

The 40 meter band has 10 meters of wire on each sides (total of 20 meters both sides), the 20 meter band has 5 meters of wire on each side (total of 10 meters), while the 15 meter band has 3.38 meters of wire on each side (total of 6.77 meters). Adjust the lengths of the elements for lowest SWR on the desired operating frequency. Since there is likely interaction between the elements, always check the tuning of all the other bands when tuning the antenna for a specific band.

To view all posts about amateur radio, click here.

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


DIY Dual-Band VHF-UHF Dipole

I have built a DIY dipole antenna for VHF (2 meter) and UHF (70 cm ) bands. I used 1/4 in diameter copper tube elements. The VHF driven element is center-fed while the UHF element is coupled (placed in close proximity but not connected to the coaxial cable) with the VHF driven element. A 5 meter RG8 coaxial cable feedline is used, with no balun. The feed point is housed in a weatherproof plastic enclosure, with one side of the VHF dipole connects to the coaxial cable’s center conductor and the other side connected to the outer conductor.

DIY VHF-UHF antenna

In this particular antenna, the VHF element has a total length of 984 mm (split in the center, to form two 1/4 wavelength element with 492 mm on each side) and the UHF element is 325 mm (1/2 wavelength element, not split in the middle). Adjust the lengths of the VHF and UHF elements for lowest SWR on the desired operating frequency.

To view all posts about amateur radio, click here.

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


FT8 and other digital modes with ICOM 718

I have built a DIY interface for my ICOM 718 HF radio to send and receive audio signals to a laptop computer and control the PTT keying, for use with various digital modes such as FT8. I used a USB sound card for the audio interface, and a USB-to-serial port adapter for PPT keying.

FT8 with Icom 718

The audio output of ICOM 718 (from speaker out or Pin 12 in the accessories port) connects to the microphone in of the sound card (pink port, microphone port). The audio output of the sound card (green port, headphones port) connects to Pin 11 of the ICOM 718’s accessories port. The USB-to-serial port is then configured in the settings tab of the software WSJT-X to send pulses to the the serial port’s RTS pin, which then controls a BC547 transistor to key the PTT (Pin 3 in ICOM 718’s accessories port) when transmitting a signal.

DIY USB soundcard interface

The circuit board of the USB sound card and the USB-to-serial adapter are then removed from their housing and soldered directly on to a USB hub. This configuration allows both modules to work with just one USB port of the laptop. I then put everything inside the metal casing of the radio, in a section protected from radio interference. To operate in digital modes, I only need to connect one USB cable from the radio.

During my initial tests, I was able to contact a station in Brazil (South America), from the Philippines, at 21.074 MHz (15 meters), using a 40-meter band center-fed dipole wire antenna resonant to the 15-meter band.

To view all posts about amateur radio, click here.

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


Sky-Watcher Equinox 100 ED

The 2011 Sky-Watcher Equinox 100 ED 4 in f/9 refractor serves as my main telescope both for visual observation and astrophotography. The Optical Tube Assembly (OTA) features a 4-in f/9 extra-low dispersion (ED) apochromatic (APO) lens design. It has a 2-inch dual-speed Crayford focuser with a thumbscrew underneath for locking the draw tube. The telescope comes with aluminum-lined wooden carrying case. It is supplied with two eyepieces: 25 mm and 5 mm. Supplied also is a 90-degree 2-inch diagonal mirror and an 8 by 50 finder scope.

In 2021, the telescope has been modified and fitted with a DIY reducer, making the telescope faster (from f/9 to f/5.65, at 0.63x ) and also reducing the tube length by 20 cm.

To view images taken with this telescope, click here.

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