First Portable (ish) HF Antenna

I have always been a sucker for the sound and nature of HF radio. The hollow, distant and sometimes ethereal voices always seemed to be travelling a very long way. More so on a hot summers night somewhere in the outback.

This probably stemmed from the long trips to the country that I was taken on with Mum and Dad, be it holidays to visit relations in the Wheatbelt, the long trips to Port Hedland or the odd sojourn prospecting, the old AM broadcast radio was always on ABC, always there along with the static crashes of some distant thunderstorm.

Later, it was 27MHz SSB, Radio Club at school with a regular sched on 80m, listening to marine HF (Perth Radio VIP back then) and their scheduled callbacks to maritime vessels.

Constructing my first HF dipole and listening to 40m (albeit on a tapped whip), I was struck by the same sense of open distance that I had as a kid. It was then that I decided to make a concerted effort to complete the dipole in time for a trip to visit my parents in Kalbarri, 6 hours north of Perth, and attempt some contacts. Maybe listen to the Sunday morning broadcast and participate in the callbacks.

I have been extremely lucky to have an old friend (and fellow hoarder) that has been an Amateur Radio Operator since the mid-1980’s. This has meant that radios, technical expertise and random parts have been very readily available. A new Operator couldn’t ask for more!

Out of his overflowing shack, some wire was located, along with the phrase’ “.. here is some stuff I picked up at a Hamfest a few years back ..”.
This is a code I have come to recognise as, “I have had this stuff for a while, used some and saved the rest, which has followed me and the YL across the Nullabor a couple of times. It is really good and I can’t bear the thought of parting with it except for serious use”. In this case it is old Defense standard communications wire; strands of tinned copper and stainless steel encased in a very tough dielectric. Some may say ‘bomb proof’.

So, the elements were ready, just need to create a feedpoint. A quick visit to the J store down the road and I was the pround owner of a couple of opaque Jiffy boxes (I only remembered them coming in black with an aluminium lid) and some miscellaneous connectors, adapters and other hardware. I already had a small toroid from when said friend was instructing me in balun construction whilst preparing for my license. It was time to make one for real. Following the instructions in the Foundation License Handbook (as good a place to start as any) I set to work. Cross check all my connections, shove it all into the Jiffy box, add a SO-239 panel socket to the end and that’s it!

Testing came in the form of elevating the feed point as high as possible and stretching the elements out along the pencil pines at the front of the house. The top of a 3.5m length of conduit was about as far up as I could get the feed … and no match. The antenna wouldn’t tune on the cut length of 40m. Oh well, I’ll take it with me and see if I can do anything with it once I get up north. Too late to do anything else with it now.

Arrived in Kalbarri and the first couple of days were filled with fixing stuff Dad had broken or couldn’t remember how to use; computer (remove search bars from browser), aircon (clean filters), TV (retune) … etc and the obligatory sitting on the beach each afternoon drinking beer and pretending to fish.

Dad fishing at Red Bluff

Then the temperature came up a bit and most of the family were confined to airconditioned quarters after midday, for the next 5 days, as the maxima wandered past 43°C. Ideal time for playing radios.

Dig out the supposedly non-functioning dipole again and have another go. Elevate feedpoint by chucking a rope over one of the tallest branches of an olive tree out the front, pull the radials out and tether the ends to a couple of anchors (okay, trees), tune and … a match on 40m. Not sure what was wrong previously but there it was and a tuned match on a harmonic for 10m as well!

The next test was a live QSO. CQ’s in the late afternoon yielded no joy. Only few QSO’s in english could be heard from various parts of VK and many from overseas parts. Tried listening for SOTA activators whenever the Goat bleated at me, also to no avail. The next best thing? Send an SMS to old friend in Perth and get him to pick a frequency not completely laden with QRM at his end.

Despite evidence from others, I never thought that I would make 10W go so far! I was so surprised and excited when I heard the call on 7150kHz that I nearly forgot to announce our callsigns.

I did end up listening to the 40m news broadcast on Sunday morning and participated in the callback, albeit from the beach carpark on the tapped whip. Signal reports were well down on the dipole.

Signal reports on a QSO later that Sunday on the dipole were 3/7 to VK6AXB in a southern suburb of Perth, 5/9 to VK6JES in Geraldton, 90 minutes south of my QTH, and barely readable to VK6AEK/p in Albany (a squidge over 900km as the crow flies) on the south coast of WA. The low noise floor meant I had good copies on all stations.
I have no S meter so I guesstimated VK6AXB at 4/8 (100W PEP/5m AGL/dipole end-on), VK6JES 5/9 and VK6AEK/p at 3/6 ish. Once I had started a QSO with VK6AXB, VK6JES and VK6AEK/p piped up as they were cruising the band. I must remember to be patient and call CQ longer next time.

A successful outing, in the end, and a proof-of-concept for future portable operation with a view to the opening of SOTA in VK6.

Heaps of thanks to VK6AXB for all his assistance and VK6JES & VK6AEK for the contacts.


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