2025 started with some storms, flooding some equipment, bringing down trees and creating some power outages, typically accompanied with power surges. Our resident Godzilla was also very busy in taking down a couple of our security cameras. Few impromptu working bees were organised.
In January, a power surge destroyed a “vintage” Cisco switch and a router at the Hut. Few visits were required by different parties to replace and by-pass the faulty equipment. Many thanks to Glen VK2FWOO, Connie VK2CON, Yves VK2AUJ and Tim VK2TIJ. (15, 16 & 17 Jan-2025).
New security cameras were ordered and configured by Glen VK2FWWO. Sean VK2THT and Alex XYL spent an afternoon installing the cameras whilst Glen was testing remotely. Luckily they were able to complete the tasks just before another destructive storm hit Sydney (27-Jan-2025).
The on the 1st February following some preliminary investigations Wednesday evening an impromptu working bee at the Hall was organised by Dom. There had been reports of some club antennas not working well. Sean VK2THT turned up for moral support as well.
Simon VK2YU, Tim VK2TIJ, and Dom VK2JNA arrived by 9am and started work with the 40m dipole. First, some offending tree branches were identified and pruned away.
On Wednesday evening, a DC continuity test had concluded that at least the coax cable was intact, so the antenna was swept with a RigExpert. The antenna turned out to be working, but out of band: too long – who knew antennas could grow when you weren’t looking?! Calculations showed that the dipole was 1.7% too long (two hand spans on each end). A trim, a remount, and all was good.
Next was the 30m “L” dipole. It too was out of band: again, too long. Tim also suggested that with one or two twigs being trimmed “we could mount it like a proper dipole”. 45 minutes later the team had the dipole in position, to find that it was “three hands” too long at each end (being mindful that is a calibrated hand – without taking into account the heat of the day).
In picture below, Red and Yellow are the arms of the dipole. It has a predominantly North-South orientation.
Then, reports of the TH-6 tri-bander HF beam playing up were investigated: it worked well today with contacts into California & SWR looking good on all three bands. Performance has been a bit hit and miss in recent months, with suspicion of a leaky balun allowing water ingress, so we’ll order a new balun.
Meanwhile, Glen VK2FWOO, Yves VK2AUJ, and Richard VK2SKY investigated problems with remote access to the 2m and 30m APRS IGates; these were both resolved, and the 30m IGate is now hearing APRS beacon again, thanks to the “proper dipole”!
UPDATE: the following morning (20hrs later) we had been credited for 65 positions packets by aprs.fi for the first day of February 2025, in January 2025 the total credits for the month was 46 packets – wow! much better installation!
Story by Dom VK2JNA; thanks to Dom and Simon VK2YU for the photos!
I used to use Kevlar wire for my random wire antenna, but now I’m using Dyneema fishing line. It seems stronger; at least it’s hard to cut with scissors.
Yu
VK2VCU BG5VCU
I think what we’ve regularly found is that over time, our home made dipoles “stretch”. This is ok & is the reason I like to have them supported at the feed-point so that they are not under great tension. Standard copper is ductile & will stretch under any tension. We just need to be mindful that they may need some re-calibration (the “chop”) every few years 🙂
Maybe we should consider investing in some Kevlar wire to combat the stretching. It’s available from ARNSW.
73 Richard VK2SKY
I used to use Kevlar wire for my random wire antenna, but now I’m using Dyneema fishing line. It seems stronger; at least it’s hard to cut with scissors.
Yu
VK2VCU BG5VCU
Hi Yu,
I use bungee cord at the ends of my Kevlar wire OCF: it takes the temporary strain of the supporting trees swaying or dropping branches falling on the antenna. Five years and no problems so far. 🙂
73 Richard VK2SKY