Tag Archives: SOTA

A compact Arduino, si5351 VFO with Keyer and OLED display

The remarkable compact transceivers of Peter DK7IH inspired me to dream up a compact transceiver of my own. This project would be an experiment on a shirt-pocket scale — not as dense as some of Peter’s rigs, but small on my scale. Starting with the PLL VFO/controller along the familiar lines of Raduino (Arduino Nano and si5351), I sketched out a physical design, and it became clear that the display choice would dictate the size of this module. Where small displays are concerned, there’s only one option … OLED.

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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.

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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.

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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.

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‘Summit Prowler IV’ — Homebrew 160m to 17m QRP SSB/CW transceiver for portable and SOTA use

‘Summit Prowler IV’ is a scratch-built six-band SSB and CW transceiver, designed for portable and SOTA activations. It is based on Leon VK2DOB’s MST3 (Minimal Sideband Transceiver, third version) from 2016, with alterations to support multiple bands, my Arduino-based digital VFO/controller and keyer, and a few extras to support portable operating. The transceiver is a conventional single-conversion superhet with 12MHz IF and an si5351 and Arduino Nano-based digital VFO. This project comes after having done more than 50 activations with my 2013 MST Mk I kit radio on 40m SSB. This rig has performed well on 40m SSB (and CW after I added it) and has launched my interest in SOTA activating, turning me into an occasional weekend ‘summit prowler‘.

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Mt Hotham SOTA Weekend Feb 2-4 2018

VK3’s ARH, YY and PF on Mt Murray.

On the weekend of the 3rd and 4th Feb 2018 I joined about 18 others at Brian VK3MCD’s now annual VK Mt Hotham SOTA weekend, starting with a night on Mt Buffalo camping at Lake Catani the night before, and with some activations at Falls Creek on Friday. With the summits at Mt Buffalo (The Horn, The Hump) and Falls Creek (Mt Nelse, Mt Cope), then 2 days four wheel driving, I accumulated 124 activator points.  A productive long weekend!

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Mt Torbreck, Pyramid Hill and Sugarloaf Peak 2017

The Melbourne Cup, a hugely hyped horse race affords Melburnians with a three day long weekend, allowing yours truly, being disinterested in all things equestrian, a day in the Victorian mountains, my first activations for more than 3 months. Mt Torbreck VK3/VN-001 in the Rubicon Range just south of Eildon would start the day, followed by nearby Pyramid Hill and the peak in the Cathedral Ranges if time and energy allowed.  Leaving Melbourne suburbs early, I turned the ignition key at 6:10am and drove towards Eildon, then south down Snobs Creek Rd to Conns Gap Rd, parking at Barnewall Plains Track by 0812, 2 hours and 2 minutes drive time.  The temperature was 8.5C.  The gate was open and a proper 4WD would have ploughed up the first steep section, but I happily walked the kilometer or so to the camping area then up the track to the summit. Steep, but with rewarding scenery, although the summit was in mist and just under cloud.

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Homebrew 40m SSB rig gets CW, keyer, break-in, AGC and metering

A couple of ‘solder sessions’ finished all the wiring, debugging and testing required to deploy my Arduino Nano keyer and SWR/power meter, and the LED LDR AGC and S-meter modules into my homebrew 40 meter SSB rig (MST Mk1 from OzQrp).  Before reassembly I sprayed the front and rear panels, and added my preferred DecaDry white lettering and a protective coat of  clear satin sealer. It’s now resplendent with all the expected features of a SSB/CW monoband portable rig.

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Hotham SOTA weekend 2017

Q: How many SOTA activators does it take to change a light globe?

A: Nine. One to alert the impending globe change (subject to weather), one to take the bulb and socket to the top of a summit, one to spot when in sight of the bulb, four to replace the bulb while logging UTC and local conditions, one to take photos as the replacement is done, and one to upload the globe replacement details into an online database and write about it all on a blog.

Nine. That’s how many VK3s spent the weekend at Peninsula ski lodge on Mt Hotham for the 2017 SOTA Hotham weekend. It was my first attendance. I met Brian VK3MCD, Peter 3PF, Alan 3FDIM, Ken 3KIM, Ron 3AFW, Glen 3YY, Allen 3ARH, Tony 3CAT and Ron and Glen’s partners for two days of SOTA activations, map reading and socialising.

 Morning of Sunday 26th Feb 2017, looking out the Peninsula lodge window south.  

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Three summits on Mt Buffalo: The Hump (VK3/VE-019), The Horn (VE-014) and Mt McLeod (VE-034) 2017

The annual Australia Day holiday, Thursday January 26th 2017, set up an opportunity for a break and some alpine walking and activating.  Leaving Melbourne on Wednesday 25th I drove to Mt Buffalo and camped at Lake Catani on the Mt Buffalo plateau. Mt Buffalo is a mountain plateau (1400 meters) and national park, about 350 km north east of Melbourne.  This is a sub-alpine camp site which must be reserved ahead of arrival with Parks Victoria. There are lots of good camping spots under low snow-gums, a pristine fresh water lake that you can swim in, hot showers, no drinking water, and (apparently) a population of endemic dingoes.  Just down the road is former ski spot Dingo Dell, where I’ve ski’d many years earlier.  I had no idea that it is named after these Australian native dogs.

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WA2MZE

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Paul Gacek

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