SFI > 250 or bust!

Or: The one with the fishing pole support. No idea when and where but I’m sure when the day comes this thing will receive a warm welcome.

The much touted (well… on these pages at least) portable mast system has solved many of our field day worries. One that remains: an easy yet stable support for the ten or twelve meter high fishing rods that keep the dipole ends up in the air. In our previous FD campaigns we hammered a wooden fence pole in the ground and put the fishing rod against it. Then clamp it down with a liberal amount of ty-raps. This often made the pole rotate around the wooden post and skew towards ground. Maybe my latest little welding project can help to set things straight. Pun intended.

Ingredients taken from my stock: one piece of angle stock 30x30x3 mm. Three ends of concrete rebar, each 30 cm long. And a steel car rim I kindly got for free from the local tire shop owner. Double the numbers for two items because even in these modern times, the Greek di still means two and a dipole still has one pair of legs.

But how to keep this thing on the ground? Concrete blocks? Not kind to our backs, knees and hips. Furthermore my trailer will already be close to its maximum payload without concrete blocks. What about steel bars bent in an L-shape jacked into the ground? Again more weight and physical exhaustion from the hammering. We’re not quite in our twenties anymore. And even drifting far away from that. I came across the ultimate solution for this. It just seemed too crazy not to buy and use these:


Actually these are tent pegs. But aren’t radio amateurs known for using everything in a way it wasn’t designed for? I found these at Germany’s biggest online ham store. The anchor points are three pieces of 5 or 6 mm thick flat stock that I welded to the rim. It pays to know how to calculate the circumference of a circle from the diameter and to scribble a long division on the back of a DIY-store receipt. The receipt was for a 25 mm drill I picked up earlier that day. That’s the size of the hole to put the tent peg through and my largest drill bit was only 17 mm. A 25 mm hole through five millimeter thick plate isn’t a joke. The drill bit is rather long and I couldn’t lower my drill press’ platform low enough. It took some thinking and fitting but I managed to make clean holes. I deburred the holes with my step drill and when it stopped raining that evening, I got out the stick welder and fired away. Not bad for a few hours of casual construction work. Most time went into drilling the six big holes.

About the audio: The camera has a very noisy autofocus and the camera was less than 1″ away from my mouth and nose. Not easy shooting this while doing that.

Below you can see the project’s inauguration. It held an eight meter long fishing pole in the air. It’s not perfectly straight but that’s because of the terrain and I didn’t bother to  level the base. The L-stock is perfectly square to the rim. Or as this guy would say: ‘close enough to close enough’. This finished product was used for a single RX loop in the WAECW contest. With two persons it should take about a minute to anchor the construction to the ground and strap the pole to it. Looks like a real FD asset.

2 Responses to Secret Weapons of the Field Day Army

  • Nice solution though the (Mazda) rim is quite heavy to take with you for a fieldday. Personally I use a simple solution with just one ground anchor instead of a rim. At one meter height I attached 3 wires as guy lines which I attach to the soil with normal tent pegs (the one you use are for rocky ground I guess). Well the picture says more then words: http://pe4bas.blogspot.nl/2015/09/iaru-ssb-fieldday-pe4bas.html. My 12m pole in windy condition at top of a dyke. 73, Bas

    • Hello Bas, thanks for the comment.
      Weight is not a real problem because I put it all on my trailer. I can haul more than 500 kg so it doesn’t really matter.
      It probably is overkill but I found these screw anchors so much fun I wanted to use them and I had always wanted to do a project with a car rim. We already have a BBQ and a fire pit so this is what it became.
      That said screwing in the anchors goes faster than hammering down something. And much easier to get it out. Play the video backwards and convince yourself :o)


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