Background
From time to time I’m asked about the detail behind the Comet HFJ-350M antenna seen in the background of this photo and how I set up my antenna. This page details out the bill of materials and the photos how it is set up. If you want to read up about this antenna in-depth check out this quick write-up from VE3IPS.
Overview
Bill of materials (not prescriptive but to give you ideas):
- Comet HFJ-350M antenna
- Tripod with removable plate
- Extra large removable plate
- SO-239/UHF F-F Bulkhead connector
- Jumper leads
- 30AWG hookup wire
- 1 oz fishing lead weights
- 2″ or 3″ diameter Fly fishing reels
- A piece of string for quick band changes, marked for length of whip per band
BOM notes: Don’t take all of my links above to heart, any tripod this style will do, any plate will do as long as it fits the tripod, any fly fishing reel will do, you just need something to hold the wire and wrap it up easily, any wire will do for the counterpoise, I chose lightweight and it’s cheap to boot. Last but not least there are two versions of this antenna, one that covers 6m-80m and another that adds a coil and covers 6m-160m. And any old chunk of string will do, too.
The first problem I needed to solve was how to mount the bulkhead connector and mount it onto the head of the tripod itself. The long camera plate was the solution. A quick pass with the drill later and my bulkhead was mounted. In my case it was an N connector female bulkhead with a short cable which I worked around with an adapter and a female SO-239 crimp at the other end. The next problem I needed to solve was how to add the counterpoise wires to the base of the antenna. This was easily done with a couple of jumper leads I had laying about the shop.
As VE3IPS says this antenna requires a counterpoise as it is a base loaded vertical. I choose to use 30AWG black hookup wire because it’s cheap and nearly invisible once laid on the ground. I wrap it up on fly fishing reels for ease of handling and note this gage of wire tangles easily, it’s only downside. At the far end I have an alligator clip upon which I clip the fishing weight so it stays taught and in place when I lay it out. Small carabiners stay in the kit just in case I need them for routing a cable neatly around the tripod or camp.
Take the time to build out counterpoises for each band. I have gotten away with making 2000km contacts at 10W CW with only one each 80m and 40m counterpoise while operating on 20m, but performance is better with more radials per band.
The thing I like most about this kit is the tripod came with its own carry bag and most of the kit fits in the bag. Super-cool and easy to carry about.
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