Cushcraft A50-3S

A50-3S standing ready.

A year ago I found a deal on a used Cushcraft A50-3S. I managed to scoop up this barely-used antenna for $80. It was missing the mast U-bolts, which set me back about $10 from Cushcraft. For less than $100, I had a functional 6m beam, which languished in my basement for way too many months.

I fixed that problem the past weekend. I got the 6m beam outside, put it on a mast and checked the SWR. My dimensions came out perfect, as the SWR curves were exactly where they were supposed to be.

The mast was something I had lying around. It originally supported a Butternut HF-4B beam and a long 17-element F9FT 2m beam. That was a long time ago - about 25 years.

The mast consists of two 10 foot sections of EMT. I would normally not recommend using EMT as a mast material. It's not a structural support, and the metal alloy is fairly ductile, as it is meant for bending. For really light-duty service, it can be adequate.

Sawhorses make for quick tune check

I don't remember the exact sizes of the tubes. I think the bottom tube is 1 1/2" EMT, and the top is 1 1/4" EMT. The top tube slides easily into the larger bottom tube. A 1/4" bolt about 12" from the top of the larger tube supports the smaller tube, giving an overall length just shy of 19 feet. An EMT coupler with some long bolts keeps the smaller tube firmly against the wall of the larger tube.

With the mast across the sawhorses, and the reflector just off the ground, the antenna is easily checked for tuning.

With that done, I just needed a way to hold the mast vertical. I already had an eight foot mast in the yard that used to hold the Cushcraft R7000. With a couple of short pieces of rope, the 19 foot mast was lashed to the eight foot mast. And, voila!

The lashings hold the mast firmly, but it can be rotated by hand. (aka Armstrong rotation) It may only be temporary for now, but it works quite well. I put many 6m stations in my log this weekend on FT8. It's good to have a real 6m antenna!