2018 ARRL September VHF

updated 2021-01-16

The previous contest went well enough, but revealed some weaknesses. First, the process of setting up and tearing down at each new grid took forever, as well as being exhausting. Second, I was having difficulty activating the northernmost grids: BP42 and BP52. Those two grids are quite far from Anchorage, leading to a long drive time as well as weak signal strengths on both sides of the contact.

Planning a rover route always involves a number of compromises. More drive time leads to more grids, which means additional multipliers. However, more drive time also means less radio time. You are always making compromises, and sometimes they pay off. But that is also part of the fun of rover routes. When you add in the variables of location and time to the usual challenges of a contest you sometimes come out ahead, and sometimes not.

VHF rover on the side of the road above Anchorage, Alaska
My favorite site for VHF work: on Alpweg and Meadow up above Anchorage

One thing that was definitely working in my favor was my new antenna setup. The WA5VJB Yagis I used previously turned out to be less than reliable under road conditions. They were good antennas, but the elements were too thin for anything but the gentlest field usage. Also, the direct connection of coax to the driven element was prone to coming loose.

After spending a ton of time searching around for a design which met my needs I eventually decided to design my own antennas. Existing designs always had characteristics I disliked: narrow SWR bandwidth, delicate elements, or complex matching networks. What I wanted was something different: direct 50 ohm feed, simple split dipole driven elements, and at coverage of the entire band.

VHF rover antennas on a mobile vehicle
The new antenna stack in operation for the first time – vertically polarized for Alaska use

After a steep learning curve with 4NEC2 I eventually came up with two designs I was happy with. A few mad building sessions later and I was in business! The antennas did everything that I wanted, and worked great during the event. SWR was low, gain was high, and the antennas proved to be very durable.

Moose on the side of the road
In Alaska even the moose come out for the contests!

The first grid of the day was BP52, at my usual spot up by the Flattop Peak trailhead. After that I headed down to ground level and went to Kincaid park for BP41. This grid was a thorn in my side for a long time. There are plenty of vehicle-accessible high points around (mostly in Kincaid Park), but the local horizon is cluttered by trees and other hills. I was always able to make contacts, but I also suspected that some weaker stations were not getting through.

VHF contest rover in a parking lot in Anchorage
Operating from the parking lot at Kincaid park, in Anchorage. (I now use Point Woronzof for this grid.)

In any case, I managed to wheel in some contacts and even ran into a fellow ham while I was there. With that grid in the bag it was time to head north again.

Interior of a truck with a radio, rotator, and tablet
Upgraded station: Yaesu 857 radio, MFJ rotator control, power supply, and tablet running APRS Droid.

Along with improvements outside the vehicle, I made other improvements inside. For power I was using the vehicle itself. I connected a tie-in from the main battery to a power pole distribution block in the cab. That powered the radio (Yaesu 857) as well as a 120V inverter.

I switched the inverter on and off as needed to power the MFJ rotator. My antennas provide decent gain, but are not so tightly-focused that they have to be re-pointed for every contact. Power draw for the rotator was therefore minimal.

On this trip I was not set up for computer logging, but I did have a good APRS system in place. I had a Yaesu 8900 mounted in the vehicle permanently, so I connected that radio to a Mobilinkd and an Android tablet. With APRSDroid running and offline maps pre-loaded I had a perfect off-grid APRS system to let others know where I was at.

KL7BSC Brandon Clark standing beside VHF rover vehicle
Final stop of the day, up in Willow, Alaska

Heading north to activate BP41 and BP51 was always a double-edged sword.

Making contacts from those grids would earn me more multipliers, but there were no local stations in that grid who were on-air. That meant that I had to reach stations back in Anchorage, a distance of some 60 miles. 60 miles is an easy distance for VHF and UHF contacts, but there were some hiccups:

  • Many stations in Anchorage and the Mat-Su have VHF capability only for working repeaters. There are a lot of low-elevation, low-gain antennas in use. It doesn’t take much to contact a mountaintop repeater. Working long distance ground-to-ground contacts requires takes more capability.
  • The road-accessible parts of BP41 and BP51 are all low elevation. Unless you are going to tote around a 100′ tower you will have to make it work ground ground level.
  • All the roads look like the photo below: trees, trees, and more trees.
View through a vehicle dash looking at a forest in Alaska
You would never think that 70 cm signals would get through that forest, but they did.

On this trip I managed to activate both grids, but with only one or two contacts from each. There were some decent VHF stations in Big Lake that came in handy when they were on the air, and one or two in on the Anchorage hillside who could make the contact work. The route was success, but I was beginning to doubt the value of activating those two grids. Thoughts for the future turned to the Kenai Peninsula.