My first setup consisted of horizontal loops for 50, 144, and 432 MHz…
I decided to try my hand at VHF contesting in 2022. Being a mobile-only operator, what better way to contest than as a “Rover?” Rovers are not always mobile; some are portable. Rovers move from one Maidenhead grid square to another during the course of a contest. Moving to another grid square allows stations to work each Rover as a new station. Each new grid means a new contact, even with repeat stations. A team of Rovers can accumulate quite a load of contest points by moving between the squares and then working each other and the other same stations after each crossing, a process known as “grid circling.”
This photo includes the horizontal loops shown above, Yagis for 50, 144, and 432 MHz, two HF antennas, and more…
ARRL has three categories for Rovers: Classic, Unlimited, and Limited. I will focus my efforts in the Limited category, which is confined to 6m, 2m, 1.25cm, and 70cm (50MHz, 144MHz, 222MHz, and 432MHz) and has power restrictions (200W at 50 and 144MHz; 100W at 222 and 432MHz). The most successful Rovers have directional beams to focus their signal toward their intended contacts. They also have a large e-mail list that they can use to promote themselves and their friends ahead of time. Being new to VHF/UHF contesting, I have not yet developed such a list of contacts; but I suspect I will make some connections as I gain more experience.
I started my build by reinstalling my discontinued Yaesu FT-857D multi-band/multi-mode transceiver. It was the least expensive way to start using weak signal modes on VHF/UHF. Ironically, my FT-857D was not used for SSB modes above 50 MHz for its first 15 years. Next, I acquired horizontally-polarized 6m, 2m, 70cm loops by M2Inc.com. That was a modest setup and less effective than what most Rovers use. But it was quick to buy and install on short notice so that I could participate in CQ’s World Wide VHF Contest. I used the CQ VHF contest as a training run for ARRL’s larger VHF contests, which occur in January, June, and September.
In 2023, I constructed a 39-inch “micro-tower” that has a Yaesu G-450ADC rotator and three horizontal beam antennas. For 50 MHz, I chose an SE-6MB Moxon by SAL Electronics. It’s a folded two element Yagi-Uda antennas with 3.7 dBd of gain and a front-to-back ratio of 17 dB, which is excellent for rejecting off-axis noise. My other antennas are “Rover Specials” by Directive Systems & Engineering. They feature 8-ft booms to keep them road-legal. The DSE144-6RS is a 6-element Yagi with 10.1 dBd of gain and the DSEFO432-15RS is a 15-element Yagi with 13.5 dBd of gain. I will add a DSEFO222-10RS 10-element Yagi when I’m ready to add a 222 MHz transverter. All of these antennas will accept 1000 watts or more, which is far more than I will ever use in a mobile application. Read more about this tower project here.
Later, I built what I will call my “Compact Module” after being asked to bring a VHF setup to a group Parks on the Air activation. I wanted better reach than what my horizontal loops provide, but not the commitment of mounting and traveling with my 75-lb micro-tower. My compact tower is half the height of the micro-tower and has just two Moxons, one for 6m and another for 2m, which are my most commonly used 50+ MHz bands. I use the SE-6MB Moxon (above) for 50 MHz and SAL Electronics’ SE-2MC for 144 MHz. The Moxons have about 3 dBd of gain on each band and can travel sideways down the road for compact width (tree avoidance). So far, the setup seems like a great compromise between my Contest and Loop Modules.
How do I get so many feed lines out of the car and to the roof? At first, I simply fed the coaxial cables into the car through a rear window and sealed it using a piece of pipe insulation. Soon thereafter, I created a pass-thru with 3/16″ HPDE (plastic) that mimics the shape of the window and has weather-sealed Type-N connectors, making the setup completely modular and easy to remove. I currently have eight ports, four for the loops and four for the beams. The interior side is pre-drilled to eventually accept up to ten Type-N ports. I still have use of the rear door so that I can access the equipment area that’s just inside and under an access panel while all of the feed lines are connected.
Eventually, I upgraded my “micro-tower” to a manufactured product by Amerite and Rohn…
The “antenna farm” makes for a cool photograph. However, each of these setups provide at least a little interference with each other. As a result, I don’t frequently run with them all. I’ve designed the “Loop Module,” “Contest Module,” and “Compact Module” to be easy to mount and remove individually as needed. I also can run in “stripper mode” with roof rack removed and just the dual-bander mounted to the roof. My car usually has its roof rack mounted since I mount the Loop Module about 2-3 days per week. Having the rack mounted nearly full-time provided the option to go completely nuts! Learn more about that setup on my Antenna Farm page.
See You on the Air!
Scott
