Adventures in Urban HF Portable – Part 0.75 (The Delay, Part Two)

Silencing the crickets, sort of…

My goodness, after promising a soon to follow update all of four months ago, it’s been all quiet on the blog since then. What has happened?

Well, the biggest was some departures at work that caused everything to get busy in the final months of last year. This more or less resulted in very little amount of time to play radio.

At this stage, however, it’s still something that I’m very much interested in continuing to pursue. With some consideration, the fan dipole is going to largely be impractical for this use, so I’ll focus my effort into the magnetic loop, as this will be convenient to setup on our office balcony. Build log to come on that once I’ve built it, but perhaps don’t hold your breath – I’m still yet to document the build of the lightweight Yagi that I used for the VHF Sprint back in October.

Apart from this, 2023 seems to be shaping up for some additional radio related fun. I’ve recently purchased a new car, a VF Commodore wagon, and as with all new vehicle purchases the first natural step is to jam a bunch of radio gear into them. Updates to follow with this as I build it out for general comms, some digital fun, as well as some high altitude balloon specific equipment which should be a bunch of fun.

Additionally, I’m hoping to get out portable in general a little bit more this year, so stay tuned for that.

AREG VHF Sprint Contest

A new addition to the South Australian amateur radio events calendar

Sunday the 23rd of October brought a new addition to the VK5 event calendar with the first inaugural AREG VHF Sprint contest.

This was a fast-paced 30 minute contest held on 144 MHz FM simplex by the Amateur Radio Experimenters Group, with the goal of both stimulating VHF simplex activity in Adelaide and surrounding areas, and to introduce or reintroduce operators to VHF operating – all while having some fun of course!

As I had been squarely in the ‘introduce’ category, having not played around much at all with VHF except for repeater operations, I knew that I had to give it a go.

Location, Location, Location

Living some ways away from the Adelaide metro area, I decided in the days leading up to the contest that I would be operating portable, choosing Windy Point Lookout as my location for the morning. At 220 metres ASL, with good forward line of sight over the Adelaide plain to the north, it would provide an excellent location especially once paired with a good antenna.

Heading out on the morning, the weather was remarkably grey for late October. Just the day before we had been blessed with a top of 20° with clear blue skies and a light breeze, however the temperature had dropped to about 15° overnight, with rain and cloud settling in. The decision was made to still head to Windy Point in these conditions as contact prospects from home would have been bleak.

The rain was heavy in places on the drive up, even worryingly so at some points, but had returned to only a drizzle by the time I arrived.

A drizzly view over Adelaide from the Windy Point Lookout

Station Setup

Arriving at Windy Point, I opted to setup the station inside the car, as while there was a perfectly situated picnic table, it had no canopy and was therefore exposed to the elements.

For an antenna, I had considered that I would likely be able to use only the 144 MHz antenna mounted on the car. However, as this was the first year of the event being held I didn’t know what to expect when it came to number of participants – including the possibility of people participating far outside the metro area, for whom a more performant antenna would be necessary in order to work them.

For this reason, I opted to construct a lightweight three element Yagi antenna to use on the day – Full details on the construction of this antenna to come in their own post.

I opted to place the antenna atop the sixth section of my 9m squidpole, with the three sections above removed. This allowed the antenna to be placed at approximately 6m above ground with no bend or flex in the squidpole, owing to an antenna weight of just 180 grams. The squidpole was then lowered slightly to finally place the antenna at 4m above ground, to ensure a sufficient length of coaxial cable could make it to the transceiver in the car.

This antenna setup performed well, with VK5ZM receiving me at S9+20db from his location approximately 20km away on Anstey Hill northeast of Adelaide. I was running six watts from my Yaesu FT818

Station setup with squidpole mounted antenna and drivers seat operating position

Contest operating

For this contest I operated interchangeably between making CQ calls, and scanning the band to find other stations, switching between the two when I couldn’t find anymore contacts to make with the operating strategy I was using at the time.

At two points in the morning I had the experience of working a miniature pileup, working three stations in rapid succession at two stages within the morning. These are by no means large pileups in the world of amateur radio contesting, but not something I’ve been able to experience before in HF contesting with my QRP power levels. That’s definitely opened my eyes to how fun fast-paced contesting can be when you’re able to operate a station that can propagate well. Perhaps some motivation to get back to studying for a license upgrade so that I can use that style of operating in some HF contests in the future.

I finished the 30 minute sprint with thirteen stations in my log – having worked VK5JGM, VK5XB, VJ5W, VL5Z, VL5X, VK5AKK, VK5WU, VK5UJ, VK5CIA, VK5SWR, VJ5M, VL5A, and VL5K.

Closing thoughts

All in all it was a wonderful morning of portable operations, and the 30 minute contest time allowed for an excellent pace relevant to the number or entrants heard, making for some relaxed Sunday morning operating.

There were certainly a couple of times during the morning where it seemed like I had worked everyone, where tuning the band only yielded stations calling CQ that I had already worked, and making calls of my own only turned up a handful of accidental replies from already worked stations. Sticking at it through these moments though, there seemed to be a steady flow of operators joining in after the start time to keep things interesting – There were certainly a couple of participants who joined later on that I was unable to work within the time period.

Additional operators joining future sprints would certainly serve to elevate the enjoyment of fast-paced operating if the 30 minute run time is kept. I do wonder if there may have been more participants this morning had the weather been nicer, and allowed more people to head out and operate from the hilltops.

A big thanks to everyone at AREG involved in putting this event together! It was a lovely time and I hope this contest has a chance to cement itself as a staple of the VK5 events calendar in the years to come.

Adventures in Urban HF Portable – Part 0.5 (The Delay)

In which fan dipoles are quick to construct, hardware is broken, and shipping from the US is slow

Almost a month with no update on the fan dipole urban HF adventure… Has cloud abandoned a new blog after the first post again? Does it really take them almost a month to build a fairly simple wire antenna? – i hear no one asking as this is an internal monologue…

No and no. let me explain.

The fan dipole has been constructed and is eagerly awaiting it’s first go on air. More will be detailed in it’s own post, but it was a quick build constructed out of some parts left over from a previous antenna project. A system for hanging it in the office window has also been devised.

The delay here is that while band conditions on 15 and 10 metres are starting to show promise, I think it’s still going to be a little while before SSB contact is possible from this location. As such, I wanted to get started using FT8. Here is where the problems arose.

A Faulty link

Earlier this year, I purchased a Digirig Mobile audio/serial interface, produced by Denis Grisak – K0TX. It’s a fantastically compact design for a Radio to PC interface, comprising of both a USB audio interface and a USB serial interface that connect to a PC with a singular cable, all packed into a case smaller than a pair of 9V batteries.

size reference for the unit, very compact – image credit:

I ordered my unit in March, and it finally arrived in May, my order having been held back so that I would receive one of the v1.9 units, instead of the v1.5 that that I ordered. Much appreciated Denis!

Upon receiving it, it unfortunately sat for several months before I finally brought it out for this adventure, where upon doing so I discovered that the device was faulty.

The audio interface component of the unit would not show up at all! multiple computers, cables, and operating systems were tried but the generic USB PnP Audio Device used in the unit failed to appear each and every time, with windows giving the cryptic message that the USB device malfunctioned, or Windows didn’t recognise it.

Digging further in device manager, the device didn’t appear under the list of sound devices, instead appearing as an unknown USB device with the message Windows has stopped this device because it has reported problems. (Code 43) A request for the USB device descriptor failed appearing in the properties for the unknown device

A Swift Resolution

Reaching the digirig forums, I found a post describing unit behaviour identical to mine. Reaching out to Denis with the information I had gathered about the fault, he quickly identified that the audio controller chip in my unit was likely faulty, and placed a replacement unit in the post. Massive thanks to Denis for getting that sorted out so quickly, especially considering that I’d had the unit for over four months before raising the issue.

That’s where we’re at now! Shipping times to Australia from the US are usually pretty slow, so I’m awaiting the unit. I’ll be getting on air with some FT8 as soon as it arrives.

Adventures in Urban HF Portable – Part 0 (The Plan)

Is this just an exercise in futility? Only time will tell

With solar cycle 25 now in full swing, this summer appears to be shaping up to give some good opportunities for HF radio contacts, and fortunately for me my amateur radio hyperfixation has appeared again while heading into Spring/Summer, rather than in March when the bands are dying down again, as it has in past years.

While operating portable or from home during the weekends should provide some good opportunities, I’d like to have the ability to work the upper HF bands at a minutes notice during the week when they’re open, which adds the requirement of being to operate from work.

While I don’t work from home, my work is quite flexible, so I should be able to fit my break times around periods where the bands are open. Being in the office though, my options for getting on air are slightly limited. The way I see it, I can either:

  1. Leave the radio at home and use my existing home VPN infrastructure to run digital modes via a connected Raspberry Pi and WSJT-X
  2. Bring a QRP radio to work and setup a compact station there.

I have some reservations about the first option with regards to how I’d handle TX timeout, and also the way in which it locks me into digital modes only, as the ability to run SSB would be much appreciated. As such, I’ve chosen to go with option 2.

Rather wonderfully, my work colleagues (shoutout systems-ade crew) have found my descriptions of some of the technical aspects of radio to be interesting, so they seem to be on board with me being able to setup a QRP station with a small antenna in the office. Bonus points if I can work some DX while they’re around!

Station Constraints

I’m somewhat fortunate that my office is at somewhat of a height (~10 floors up), and has a large window that spans the length of one of the walls. The length of this window is approximately 6 metres, which should give me couple of nice options for working on 15 and 10 metres for summer.

  • Small Magnetic Loop – This one is most ideal as it’s small to store and quick to setup
  • 15/10M Fan Dipole – Would require its 15m elements to hang down at 90 degrees at the ends to fit the space, but 10m will fit just fine.

I’ve decided to have a play with both and see how they each perform. I suspect that due to its size the loop will win out, but it’s more complex construction means it’ll be longer before I have it ready.

The fan dipole is much quicker to build in comparison, so hanging it up indoors will be the main challenge. More details to follow it it’s dedicated post.