A new car antenna mast—cheap and quick? I was inspired by Tomáš OK1GTH’s design, though I decided against including a swivel mechanism. This helps simplify the construction.
TIP: Building a car antenna mast
The base is the RACE MENABO mount head. A TV antenna bracket is bolted onto it. The mast is secured with a sturdier bracket. This design provides the necessary support for the telescoping mast. The mast is then anchored in four directions.
Installation is quick: the carrier head is mounted on the tow hitch and tightened with a socket wrench. I attach the anchor ropes and extend the mast without the antennas. Now I secure the mast. I lower it back down and mount the antennas. Since the anchoring has already been measured, the antennas will be almost precisely positioned at their working height. In the final step, I simply adjust the anchor ropes to the exact length.
Mast mount for the tow bar (the so-called “ball”)
On my first try, I managed to set up two 8-element DK7ZB Yagis on this mast in about 40 minutes. However, there’s definitely room to speed things up even further.
VHF Operating Log for April
After the switch to daylight saving time, I finally had the opportunity to set up two antenna systems. The weather on Černecký Hill is beautiful, sunny, and only slightly windy. First, I set up a smaller mast with four 5-element antennas. I wasn’t sure if the cables would be long enough, and it would be very inconvenient if it turned out later that they weren’t.
Then I set up a new mast behind the car. It’s easy to do. I have some extra length in the cable fasteners and the combiner, as well as in the antenna screws. Each boom is divided into three sections, and the joints are secured with M4 screws and wing nuts. I think screws with plastic heads would be more suitable.
The Second Antenna System
I’m having a bit of a struggle with the wiring in the car, which later turned out to be a fundamental mistake. I’m well ahead of schedule, but to save fuel in the generator, I don’t start it until 20 minutes before the VHF PA begins. I notice that the antennas on the new mast seem to be dead… so the usual antenna system will have to save the day.
The second annoyance is the lack of aircraft data, which prevents me from using AirScout.
I can’t even make some contacts with stations from the southeast. I alternate between calling and occasionally switching to an easier contact. In the first hour, I make 43 contacts.
The second hour is mainly about multipliers, with HA5OO bringing in the nearby JN97, and YO5PW bringing in KN17. Following that, E77P from JN83 makes a surprise appearance, and I4GHG from JN63 wraps up the hour.
In the final hour, contacts toward the southeast are also successful: E76SB, E75M, YU7CW, and YT7KW. These are supplemented mainly by stations from OK. I tried to work stations from DL, but this time I didn’t manage a single connection to Germany.
Map of connections in the April VHF PA
The kilometer average barely climbed above 200 km/QSO, so 95 contacts with 23 multipliers are enough for 7,774 points. I can pack up in exactly one hour. This could be the end of it. But there’s still one reason why the antenna system on the new mast isn’t working: the connectors in the antenna switch were swapped. But I didn’t figure that out until Monday, when I noticed the connecting cable between the switch and the transceiver.