September 2018: I ‘met’ Owen KJ6AKQ on Twitter, I cant recall exactly how or when, maybe 6 months ago. He was a KJ6 who had landed (with family) for work in Melbourne, with a KX3, a real ‘ham sensibility ‘, and an obvious desire to get back into the hobby. But living in an inner city townhouse was going to cramp his style somewhat. After finding how to take out a VK3 callsign he registered VK3EAR. Callsign, rig, but no antenna. I knew he was itching to get on air when he started calling CQ on Twitter.
I suggested a number of compact antenna options, including a centre loaded 40m vertical, a linked dipole or an end fed half wave, all from VK SOTA blogs. Of these, he liked Glenn VK3YY’s shortened three band end fed (only 12.4m long) for obvious reasons. He had some tools but no soldering iron, so one weekend I knocked up the antenna, mostly as per Glenn’s instructions. I wanted to help get Owen on air, as painlessly as possible.
I used an on-hand FT114-43 toroid sourced from Minikits, all other parameters unchanged. Glenn used an T82-43 Fair-Rite toroid. I rightly, or wrongly assumed this to be equivalent to an FT82-43. I adjusted my turns on the bigger donut to match the inductance (294uH) using the indispensable toroids.info calculator. This may have turned out to be significant. More on this later.
The translucent plastic box was from Jaycar. The whole build took only about an hour and a half. Knowing Owen had an antenna analyser, I didn’t attempt to string it up and tune it, leaving something for Owen to complete, making it a joint effort.
The next day we met in the city for what hams in my youth used to refer to as an ‘eyeball QSO’. Owen is also an amateur motor mechanic and he turned up on his original 1960s Vespa, brought to Melbourne from the US west coast amongst his belongings. Owen has rebuilt the 200cc engine himself. It was gloriously authentic and rustic. I said rustic, not rusty.
Now for part two of this story it’s over to Owen.
8th Jan 2019, Owen: Hey Paul, I’ll be going down to Dromana this weekend and taking the radio for its first Aussie outing, I hope … it will likely just be a short op at the beach to test things out.
I asked him if he had a quarter wave counterpoise. He said no, on the basis that Glenn VK3YY does not mention one. I thought you conventionally feed an end fed against counterpoise. I asked Glenn via his blog. Glenn confirmed that he generally doesn’t use one. I later realised that this antenna approximates a half wave, not a quarter wave resonator, so the earth is not necessary.
A few days later Owen reported on his first attempt from the beach to tune up the antenna.
I’m afraid the antenna wire isn’t long enough! It was resonant at 8.400 and 14.200. Doesn’t look like there is a dip at a lower freq.
Then, a bit later he reported from back in the beach house…
Well the antenna dimensions seem spot on, 52 turns for the coil and 1.8m and 10.4m for the wire, plus a bit for trimming.
Very weird. I restored it to the length you started with. It is perfect on 20 and decent on 10, but the dip on 40 is so sharp that it’s still over 8:1 swr at 7100.
Owen retired for the day. A disappointing start to his VK operations. But before I’d had time to contemplate the predicament, this message appeared on WhatsApp:
I added about 2m to the short side of the antenna, and now it looks perfect!
Hahahahaha my first contact is VK3YE 😜
He’s currently in Tasmania. Barely any copy though.
An Aussie ham radio celebrity.
Owen tweeted his story. Here, we see him on the sand, squid pole supporting the shortened multiband end fed on a fence post.
Check out @literatesavant’s Tweet: https://twitter.com/literatesavant/status/1084280164941389826?s=09
To cap it off, Peter VK3YE posted a video of his QRP portable session from Cygnet a few days later. You can hear his QSO with Owen at 2:29.
I think I know why our version of Glenn’s end fed resonated high on 40. Glenn writes ‘The coil tunes the 40m match‘. It is likely that my different core changed things. Adding some length pulled the 8MHz resonance down to 40m. All’s well that ends well.
Welcome Owen VK3EAR.