A scratchbuilt G6LBQ BiTx ‘Walkie-Talkie’ for 40 and 20m SSB/CW

After completing a 6-band SSB/CW QRP transceiver (Summit Prowler IV) I found myself thinking about a more compact QRP SSB/CW rig for SOTA, with two of the main day-time SOTA HF bands (40/20m). The design driver this time was to try a different ‘form factor’ — I wanted a rig with a narrow and long case, such that it would easily slide inside a backpack, and on a summit sit vertically against a rock or be hand held. All my SOTA rigs so far use both front and back panels for connections and controls, so they need to sit level on a horizontal surface. As most rocks or tree stumps are low, you can’t easily read the display. Some designers get around this by putting the display on the top of the box, a sensible adaptation but one that makes the rig look like a flounder. Because I spend a lot of time building and using these radios at home on the shack bench as well as on a summit, I wanted a design for use in both situations.

Scratch-built 8-band HF/6m transceiver (EI9GQ) – Part 1 Receiver

Eamon EI9GQ’s book (‘Building a Transceiver’, RSGB 2018) started me down the path of another modular transceiver project. For this build I wanted to continue working with surface mount but without the compulsion to pack it all in tight. More space and the freedom to replace a module later. It would be a Shack Sloth rig (a base station), not a Summit Prowler, so the space, weight and power budget shackles fell off from the start.

Remembrance Day Contest 2018

Remembrance Day Contest is a 24 hour amateur radio operating contest conducted each year by the Wireless Institute of Australia, to commemorate those Australian licensed amateur radio operators who lost their lives in World War 2. It is ‘designed to encourage friendly participation and help improve the operating skills of participants‘, and is held on the weekend closest to the 15th August, the date on which hostilities ceased in the southwest Pacific. This year it commenced at 1pm local time on Saturday August 11th.

Replacing an LCD: more to it than than meets the eye

Until this weekend my homebrew QRP SSB/ CW rig (Summit Prowler IV) possessed an un-backlit black on green LCD. Unfortunately the backlight never worked. The transceiver worked well, and I overlooked the dark display, perfectly usable in daylight but useless at night unless lit with a direct table lamp. I justified it in my mind by thinking of it as not a limitation but a feature — it’s a battery saving measure in a portable rig, a design choice, not a construction failure or component fault. A few weeks ago I set it up on a side bench with no direct light and found myself shining a torch on it to tune. Finally the niggling annoyance got to the point where I could ignore it no more.

Summit Prowler IV with nice new blue display. Now ready for those twilight activations.

Federation Range (VK3/VN-029) ski day, 2018

Last year I cross country ski’d into Federation Range VK3/VN-029, 1490 meters above sea level, activated it for 8 points (+3 winter bonus points) and ski’d out again. This is possible because this summit is just off groomed cross country ski tracks at Lake Mountain, ninety minutes north east of Melbourne, a popular sight-seeing, tobogganing and cross country skiing spot. Time to do it again. After picking up skis at Marysville I took Royston Trail from the car park up the long incline, to Panorama, then Hut Trail to Boundary Hut, the remains of a hiking hut, long since burned out, only the stone walls standing to waist height. Distance out is about 4km.

Desklamp conversion to 12v DC 20w power supply

Picked up a halogen desk lamp from a street hard rubbish pile the other day. This particular desk lamp model has been a popular product for many years and appears to be still available. As I stood on what Melburnians strangely refer to as a ‘nature strip’, starting at someone else’s pile of junk, I faced a familiar dilemma– take it and do something with it, or walk away.

Arduino GPS Clock

A while back I prototyped a ublox GPS unit with an Arduino Nano on a breadboard. I wrote up some thoughts here. The ublox GPS unit streams messages on a serial line that contain a variety of time, date, location, altitude and speed fields. So one obvious application is to make these parts into a desk clock. The big advantage of a GPS clock is that it never has to be set. Just power it with 12v and you know the time is correct. Well at least until the next Carrington Event.

‘Building a Transceiver’, Eamon Skelton EI9GQ and Elaine Richards G4LFM (RSGB)

I first laid eyes on this book when Glenn VK3PE brought it to an Amateur Radio Victoria Homebrew Meeting a few months ago. Eamon Skelton EI9GQ writes the ‘Homebrew’ column in RSGB’s RadCom. I don’t see RadCom (my loss) so it was a pleasant surprise to skim the pages and see every aspect of building a relatively high quality transceiver getting a good, readable coverage, with full construction details.

Arduino GPS experiment for SOTA

How could a GPS unit integrated with a SOTA transceiver assist in activations? I’ve been turning that thought over for a while now after seeing David VK5KK’s GPS and Arduino based grid square locator (posted to the ‘VK Homebrew’ group on facebook).   The ready availability of cheap GPS units with a simple serial interface makes the option straight-forward.  As my homebrew rigs are using Arduino Nanos and si5351 breakout boards, the GPS is just another (serial) attachment.

Hard-to-find faults and other homebrew ‘Gumption traps’

I recently cut this small piece Veroboard to hold two vertically aligned miniature potentiometers on a receiver front panel. The three soldered tracks to the right allow connection of the audio signal to the volume control using shielded twin conductor cable. Very standard stuff, I’ve been wiring up audio amplifiers to volume controls like this for about four decades. But this one wouldn’t work. It has a fault — it’s there, in the picture above, right in front of your eyes… can you see it?