Author Topic: Bencher Skyhawk tri bander  (Read 6434 times)

k4lrx

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Bencher Skyhawk tri bander
« on: August 21, 2013, 11:53:48 AM »



I have been an avid DX hound since 1958, over the years I have been pretty much a Hy Gain antenna man and have gotten the results I have wanted. One to crash pile ups and secondly have the dx stations call me instead of begging for a contact due to low signal strength.

Over the last few years I have used a mono band beam, namely the 205BA for twenty meters parked on my tower at the 75-foot level. It has performed well and bored holes in the band when twenty was open to all parts of the world.

However, I had longed to work more band countries on 15 and ten when these bands opened up once again, but I was bound on twenty with a mono bander and on 40 with a folded dipole.

My mono bander worked very well until about two months ago, at first it started developing an intermittent swr, the antenna continued to work, but the problem was noticeable at times.

The final blow came during the winter months we had some ice forming on the antenna and then high winds for most of the night. The next day the swr on the 205BA would not drop less then 2.5 over the entire band.

I at first suspected coax problems and checked my connectors on the ground and they were very solid and well soldered.  Underground burial and the top 80 feet of coax were the next suspects. I later found the problem once I had taken the antenna down.  I had searched around for a suitable tri bander, or five band antenna and looked at a few models.

I had given some light thought to the Step-IR but reading all the horror stories on e ham about broken insulators, tape inside the fiberglass elements and motor trouble on the elements I really backed away from anything made by Step-IR. The more I read about all the problems on e ham listings, well I did not need a lot of problems or expense hauling the antenna up and down the tower.

My attention was drawn to the Cushcraft Kt 36, nice specs and until I read once again about cracked insulators and water getting into them causing SWR problems. I again backed away from this model as well.

In the process I was looking for a suitable tower and antenna installation service and I found that in the form of W2GD. John had a great recommendation and that was the trapless Bencher Skyhawk tribander. To be honest I never knew Bencher made yagi antennas, but in doing my homework I found out this model was designed by two big contesters that being W9INI and K3LR. Both work the DX contests and rack up huge scores every year.

In fact the Skyhawk was used by W9INI in the contests and results were amazing. I really had nothing to lose, but I would gain two more bands with a competitive  antenna. Two weeks ago the mono bander came down, I found a loose connection on the balun pigtail to the driven element. Not a good RF connection, worked fine on receive, but no good for RF.

I being a long time Dxer I was amazed at the Hawk’s performance, I put it to work on 15 the first few hours I had it in the air. The antenna offers three elements on 20, three on 15 and four on ten meters, a total of ten elements.  I aimed the antenna to Europe and sent a couple of QRZ DX on 21.003. I was bombarded by callers ranging from England to Eastern Europe, in the following days several stations in Indonesia, New Guinea, New Zealand, Niue Island, Japan, Iceland, Malta and the list goes on for about two hundred stations so far.

On twenty lots of Russian stations, Europe and Indonesia plus Japan. To be very honest I have not noticed any degradation of my signal on transmit, or receive capabilities with this antenna. It is a smaller boom then the 205BA, but it is what it does and how it does it.

With no trap loss each driven element is fed with the same balun and the results are a low swr across all of twenty and 15 and on ten to 29 mhz. As expected with the frequency/SWR graph the antenna bottoms out with swr in the middle of the bands and has a slight swr namely 1.2 at the upper and lower ends of the bands.

The overall gain Bencher claims is 6.5 dbd on 20/15 and 7.5 dbd on ten meters, in effect increasing your ERP by four times using a Dipole at the same height. Front to back ratio Bencher claims 25 to 28 dB and that is about the same figure I came up with using the antenna and peaking it on strong signals then turning it 180 degrees.

This model sells for $1250 dollars and it will require about five hours assembly time, there have been some complaints about the instructions not being clear. It all comes together once you start looking at pictures and figure out the mechanics. The elements are held in place with pop rivets, so if you do not have a pop rivet gun, you may want to buy one for this project, or rent one.

In hoisting this antenna I had a crane service out of Evansville lift it up on the tower, this prevents damaged backs, arms, plus bent elements and damage to the antenna. The choice is yours, but by using a crane the old antenna was down and new one up in a matter of an hour.

Personally, this is a great antenna and I have added several new band countries on 15, I have made a few contacts on ten, mostly South America and Central America. Ten has been for the most part pretty dead for months, but one day it will blow open and look out!

My Skyhawk is resting at 75 feet, it does well at that height and I am well pleased with its performance. In fact, some of the DX I mentioned I have worked in the 15 meter phone band, that is unusual since I am a cw man for decades.

The versatility I now have and that is a good antenna for 40/20/15/10/6 certainly adds a lot more interest in adding additional band countries to my DX challenge. I have heard of some fellows using this antenna on 17 and twelve with a little tuning on the antenna tuner. I checked out the Skyhawk on 17 and it will load up using the antenna tuner. I am not going to try an use my amp, but with 100 watts I suspect I can work something on 17 with it.

May try that project later.. OK, my thoughts on this antenna, it is a winner.

Questions, K4LRX@arrl.net