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June 12, 2024. Antennas

Invariably almost an afterthought your antenna is the critical piece of the system more so than your rig.

I have two antennas at the N6QW QTH and in reality, only one that works.

Let's talk about the one that from the git go was a disappointment. That one is a two-element beam (10/15/20M) from Mosely. I bought this one because a local ham (about 500 feet away from me) installed one. This is the TA-32 Junior which was factory modified with a high-power driven element so it could do legal limit. I have a 20M Homebrew 3CPX1500A7 amp that can do legal limit (and a bit more). The nearby neighbor bought the stock TA-32 and has had no problems.




The beam is mounted on a 33-foot Spider pole and sits 16 feet above the roof.  The whole system was well engineered with a sturdy base and house bracket plus being guyed. It has survived some 70mph winds. It just never seemed like a beam. I purchased good quality Coax from DX Engineering, and the bottom mounted rotor is from Yaesu the G450. 

After about a year of operation and only once running the legal limit on 20M it developed a strange attribute. You would connect to the beam, and you would hear signals and rotating the beam would null out signals. But the minute you hit it with 100 watts it would go deaf and the SWR went to hell. 

I suspected the coax that when RF was applied something happened to a connection, possibly heat related. But the worst part it was totally repeatable. A total failure would let you find the culprit. 

I don't do ladders and roofs and the initial final install and raising of the sectional mast was done by a contractor. 

In 2019 Covid struck, and the contractor was not too interested in coming back. A simple test was that I bought a new section of coax and would have him replace the coax and see if that resolved it. The other possible cause was the hi-power traps in the driven element. A set of replacement traps was close to $250. The coax was $100 and was a less expensive 1st step and would buy piece of mind if I also had to replace the traps.

That is when I thought screw Mosley (they were not very helpful) and if I did anything that would be to purchase a hex-beam whose footprint is likely bigger than my house. I figure about $850 should get me a hex beam with 3 bands and the added stuff that is optional but absolutely really needed. 

These days with the monthly cost of the Board and Care fees, spending $850 for a new beam is a bit in conflict with my commitment to care for the XYL.  (Those words for better or worse and in sickness and health -- sure hang heavy in any decision process)

The antenna that works very well and cost a lot less and is totally homebrew. It is an Inverted Vee that I converted to a Delta Loop fed at the top. The Vee was originally cut for 40M, and the center pole is 32 feet high. The conversion consisted of adding a length of wire to the bottom ends of the Vee and the total length is dead nuts on a full wavelength on 40M. 

I feed the antenna at the top with 450 Twin Lead, about 45 feet long, and that in turn connects to a high power 9:1 Balun (DX Engineering). From that point it is 50 Ohm coax to a homebrew 3KW T Type antenna tuner. I can work all bands with this unorthodox lash up.

Thoughts of an end fed half wavelength (EFHW) have floated through my mind but not for long. There is only so much you can do on a California small sized lot. There is also a concern for the neighbors and so far, some 12 years now -- it is OK. 

If I had more time (and $850 in pocket change), then the hex is really the answer. I have the mast, the rotor and a new chunk of coax. May need to sell off some of the boat anchor stuff. Without a serious antenna then having all sorts of rigs buys you nothing.

73's
Pete N6QW

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