Club members Simon VK2TW and Richard VK2SKY were again active with NSW State Emergency Services for their Bush Search and Rescue NavShield bush navigation event.
The event takes place in a different location each year, within a few hours’ drive of Sydney; the location is kept secret until shortly before the event to avoid teams doing any advanced research, and the course details revealed only the when the teams arrive.
The location for this year’s event was Murrumbo NSW, in the Goulburn River National Park. Teams competed in an area of about 100 square kilometres. An Incident Management Base and three radio checkpoints (RCPs), plus two P25 repeaters cross-linked to the Public Safety Network, and HF simplex links, provided communications coverage for the area.
Competing teams collect points for visiting numerous “controls” (flagged locations); each control is worth a differing number of points, depending on the difficulty of reaching them, and teams can decide which locations to visit and in which order, to maximise their score.
Conditions were quite mild compared to last year’s NavShield; there was little wind, a sprinkling of rain about 3am on Sunday morning and minimum temperature of 1.5C.
Checkpoint Alpha was the closest to Base, and so was the busiest of the three RCPs. The hilly terrain made simplex UHF comms difficult, so part of WICEN’s job was to help set up the repeaters.
It was nearly sunset by the time we got to the site for the Alpha repeater, and lugging generators and gear up to the 275m high peak provided “a good workout”. For all the effort involved, the repeater didn’t work well at the start. This turned out to be caused by the P25 repeater and the allocated PSN channel being only 150kHz apart – a bit of a worry when you have only one mast to work with! There also seemed to be an issue with the link’s power feed, so another team went up and replaced it and relocated one of the antennas to a tree as far away as the coax cable would reach!
Meanwhile, “back at the ranch”, everyone set up camp and the checkpoint. Alpha’s location was picturesque, the sandstone cliffs catching the setting sun very nicely as you can see in the photo above.
Hoping to get some “Amateur time” when things got quiet overnight, I set up my tent close to some trees so I could set up my 80/40/30/20m linked dipole for some NVIS work.
One thing I didn’t realise at first was that prickly pears were all over the place, and i had managed to pitch my tent right down top of a patch hiding in a tuft of grass. Not pleasant! The spikes pierced the base of my tent, though mercifully missed my air mattress. I duly rooted out the offending weeds and brought them to the fire pit for cremation:
My HF setup was fairly basic, with my ICOM IC-705 “go kit”, a Sotabeams 80/40/30/20m linked dipole, a 7m squid pole for support, and a Dell rugged laptop. I powered these up only when I wanted to send or receive email, so the ICOM’s internal battery lasted for most of the event. By mid-Sunday morning though, I switched to the external 7Ah LiFePO4 battery.
If you haven’t tried VARA HF Winlink, I highly recommend it. I was able to send email from my portable location to a select group of people: Jan VK2FEB at Base a few km away, other remote VRA members, and a friend in Ireland, using just 2.5W on 80m to reach Winlink gateways in VK2, VK3 and VK4. Jan replied to me using 5W into an end-fed half wave antenna to reach the ZL2SEA gateway on New Zealand’s North Island – talk about taking the scenic route!
The “scenic route” is 5465km!
Part of the point of using Winlink was to demonstrate an ability to bypass potentially damaged infrastructure, as might be expected during widespread fires or floods, using Amateur Radio.
Notwithstanding the repeater issues, communications during the event went reasonably well, and only a few casualties were reported. Considering that about 500 people participated in the event, that was pretty good!
One of the BSAR HF channels, on the 60m band, experienced some minor QRM, which we surmised was being cause by somebody’s Over The Horizon Radar. It sounded to me like the chirps newly-hatched crocodiles make as it swept down the band. I checked with the waterfall display on my IC-705, and the interfering signal seemed to be fairly localised, scanning just above and below the BSAR HF channel. Why they chose that particular frequency remains a mystery for now.
Bonus: UFO!
Skies were very clear on the Friday night, and I can’t remember when I last saw so many stars in the sky. We also saw a UFO, well, an “Unexpected Flying Object”. It was a bright light in the sky, a bit like an airliner on final approach, lighting up the misty air in front of it with its landing lights.
Except, we were (as far as I know) well off the usual flight paths, and instead of lighting up in front of it, the light seemed to change direction slowly to the sides. Second guess then was perhaps a helicopter doing a search, but we could hear no sounds that would confirm this.
Then the penny dropped and I checked the Next Spaceflight app on my phone, and “by a strange coincidence”, India had launched its Chandrayaan 3 moon shot about 20 minutes before, so probably the jettisoned booster tumbling back to Earth. Mystery solved! A subsequent news search revealed that we weren’t the only ones to see it.
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