As a part of the SOTA activation of Bimberi Peak VK1/AC-001, 1913 metres ASL, highest peak in the ACT, Al VK1RX and I planned a 30 minute session for the 2m DX aircraft enhancement window starting at 2100 UTC. We had so much fun 30 minutes quickly turned into one hour.
On our arrival at the summit on Sunday afternoon (the day before) we observed commercial aircraft at 10,000 metres flying the Sydney – Melbourne route. We could see the contrails trails or vapor trails of north and south bound aircraft. The flight path for south bound traffic is directly overhead, with that in mind I was confident we could make one or two contacts into Sydney and possibly Melbourne on Monday morning. Not having FlightRadar 24 on the phone wasn’t a big deal, we could see the contrails, if we timed our calls 2 or 3 minutes after the aircraft passed we should be close to the optimum timing for VK3 contacts.
If you can detect any concern in achieving the outcome, it’s likely to be around the TX power and the antenna. The rig is a QRP FT-817 while the antenna is a simple 2 metre dipole using 3mm enamelled copper wire mounted at 5 metres on a 7 metre squid pole, previously described in this blog.
Prior to the 2m session opening I had a chat with Andrew VK1DA on 40m 7.070. Andrew was keen to work us on 2m with a HT from his property near Yass, I would also use a HT. We tested the path with a quick contact on the Mt Ginini 2m repeater. Andrew confirmed he could hear me on the input frequency (reverse) 146.350 MHz. Changed to 146.500 simplex and sure enough a 5-5 contact with Andrew on HTs. That’s a no-fuss Andrew to Andrew (HT to HT) FM contact between Bimberi Peak QF44JI to Yass QF45LD 90 km with plenty of dirt and rocks to obstruct the signal, well done Andrew!
At 08:50 I called Mat VK1MA asking for his help in identifying 2m beacons. Listening on USB we could hear distant beacons on 144.435, 144.420 and 144.530. 420 is in Sydney while 530 is in Geelong. Hmm not bad for a QRP rig and a 2m dipole mounted on 1918 metres of dirt and rock.
So did we make the grade with 5 watts and a 1/2 wave dipole, you bet we did! Genuine VHF DX contacts were:
VK3II Jim near Phillip Island, QF21RN 428 km
VK3EJ Gordon in Cobram, QF24TB 287 km
VK3VZP Russell portable in Gippsland (point to point) no enhancement
VK3XQ Rob near Yea, QF22QQ 357 km
VK2BCC Colin in the Blue Mountains QF56DI 263 km
VK2BXT Kerry in Camden
VK2KOL Col in Homebush (point to point) no enhancement
Local contacts included Matt VK1MA, Dave VK1DJA, Ian VK1BG and Rob VK1KW.
Thanks VHF DX net, great to make the contacts from such lofty heights.
More pictures to follow in the next SOTA activation post .