About a month ago, I decided to hop up on my roof, and do the ole’ switcheroo changing the orientation of my Buckmaster OCF to see if I could possibly make contacts in areas of the world I hadn’t yet before. Being in an inverted V position, this was fairly simple, so I disconnected the balun and swapped positions of the legs. Everything was tied off nicely, legs were still the same height above the ground that they were before I made the switch. Everything should be fine right? Wrong…. SWR was just over 3 to 1 on 40m, the same on 10m, and of course it was expected on 6m, as this version of Buckmaster already had a 3 to 1 SWR on 6m (as advertised). But 20m was perfectly flat! 1 to 1. How could this be? My first thought was that ‘Well it must be interacting differently now because it’s in a different spot.’ So back up the ladder I went…. that’s what I’m known by now.. K5ACL ‘Always Climbing Ladders’ LOL!
I figured switch the orientation of the antenna back to the exact spot it was at before, and so I did, and back into the shack to check & make sure everything is ‘hopefully’ back to where it was before (or at least close?). But the issue still existed! My SWR was the same on those bands! Contacted Buckmaster and they said that if the SWR was perfect on one band, but not the others, then most likely it’s due to its surroundings. But that still doesn’t explain why it was working fine right before I switched it. Did I screw something up in the balun? I’m pretty gentle on my equipment, it wasn’t like I was swinging the balun around my head smashing it on the concrete or anything. But I had no way to check the balun! Buckmaster purposely seals these baluns with this epoxy resin container thing that is practically impossible to get into, and for good reason I suppose, but as hams, this is never a good option, because we need to be able to open things up and check out our equipment, especially antennas! I get that it has this fancy thick pvc coated wire that would last 10-20 years, but honestly that’s of no use to me when the regular ole’ household copper wire I use works just the same.
So, I thought I’d try another project, get a proper 4:1 balun from Balun Designs, and run your own wire. In doing so, I thought I’d try to squeeze out some more bands with the one I was creating by bending the legs of the OCF. I got the 4:1 balun that has the dual core stacked toroids, which is ‘supposed’ to minimize interaction of OCF’s with nearby surroundings. Skeptical of buying yet another balun, I’d heard good things about the Buckmaster antennas, but after what happened, I wasn’t sure paying another $90 for a balun was the right thing to do. Alas, I strung it up in place where the Buckmaster was, and used longer wire this time, it ended up being about 46′ on the short side, and 91′ on the other. The balun designs balun worked absolutely perfect in this application and where I have it strapped to the pole (a bit sturdier than the Buckmaster design too). Back into the shack I went to check my initial prune job on the wires. I hooked up the RigExpert AA-30 to my feedline, and to my surprise, the results were totally acceptable, just as they were! Don’t go changing anything! SWR was a tad high on 80, but I’m afraid to make any other adjustments in fear of screwing up the numbers on the other bands. That’s the only downside to making an OCF, what you see is pretty much what you get. You can play around with the location of the feed point and length of legs to find the optimum location/lengths, but with these numbers, I’m satisfied.
6 meters works too, the SWR is about 1.4 to 1 around 50.200 which is even better than the Buckmaster on 6m, this length of wire must work better. (The buckmaster had 45′ & 23′ legs). I can even use this on 30m with the tuner, the SWR registered around 4 to 1.
From what I’ve read, the height at which your apex sits also determines what type of balun you should be running. Granted the Buckmaster uses a 6:1 voltage balun, this one is a 4:1 which from what I understand is the appropriate balun for the height I have it at (about 25-30′ up). The 6:1 balun would work better if the apex were closer to 50-60 feet to bring the impedance down to the appropriate level.
I’m really happy with the performance of this 4:1 balun from Balun Designs. Time will tell how it holds up to the elements. Now to figure out what went wrong with the Buckmaster. I’m going to need to test it at a different QTH to see if the problem is replicated, if so, I know that most likely there is something wrong inside the balun. Maybe I can get a refund or a replacement since it’s still under warranty. The OCF is an understated antenna in my opinion, the magic is in the mathematical relationship to the other bands, and in the appropriate balun. My original plan was to possibly put up a fan dipole with resonant 1/2 wave lengths of wire, but that would mean I would have to string up at least 14 different wires just to work the same number of bands that I can work with these two wires!
Now time to work some contacts!