The Hamstick Vertical Dipole – Great For QRP DX, Quick & Easy To Deploy!on October 27, 2013 at 08:04
The Hamstick vertical dipole for QRP in the field has been on my mental list of experiments to try for a few months now.. But I’ve been kinda reluctant to take much time with it, knowing that a loaded whip can be a bit lossy, especially when you only have a few watts output QRP.
But when considering the ease of set-up, the lower take-off angle of radiation of a vertical which would be 27 deg or less (as compared to a horizontal dipole, and the fact that I’ve used the same Hamstick dipole in a horizontal configuration with pretty good results, I figured I just had flip this thing vertical and give it a try.
First, I had to consider how the SWR would be on such an antenna, and also a mounting configuration that would be simple, light weight, and easy to deploy.
So I began to research vertical dipoles for the HF bands, and I was surprised that there wasn’t all that much to find on the subject (compared to other designs.) I did find that there were a couple of manufacturers of vertical dipoles, and some hams were experimenting with them, but I expected to find more. Then I came across the “Buddi-pole” instruction manual that included a vertical dipole configuration along with the different take off angles of radiation with the vertical dipole at different heights.
The chart shows that with a vertical dipole mounted at only 10 feet (this is the center, or feed point of the dipole) on the 40 meter ham band, the resulting radiation pattern would yield a 27 deg take off angle, which is a pretty good angle for DX… And raising that same antenna another 15 feet would yield a 22 deg take off angle – even better.Vertical Dipole = Lower Take Off Angle
Now, if you use the same configuration on higher bands at the same height, your take off angle will decrease even more. For example: On the 20 meter ham band a vertical dipole mounted at 10 feet (center) the resulting take off angle would be 25 deg. Raising the center another 15 feet to a total of 25 feet off the ground, your DX take off angle would now be only 16 deg giving you a longer skip over all, and better possibility for great DX.
A Vertical With No Radials or Counterpoise?
The reason I usually stay away from verticals in the mountains is the need for a field of ground radials for the very best performance. I don’t have time to lay out wires in the woods, so that option is out for sure. The vertical dipole will give you the low angle radiation DX performance of a ground mounted vertical, without all the ground radials to mess with.
You simply hang it and play!
A Vertical Dipole is Easy – Set Up in Under 5 mins (with no tripod!)
I have to admit, that when considering an antenna system for the field, I am always looking for a quick and easy way to get on the air. I love the wire dipole, but the time and work involved can sometimes leave me looking for better solutions. Sometimes wires go up easy, and sometimes they can leave me very frustrated with tangled support ropes and wires!
Using trees as a support, you can get your Hamstick style vertical dipole up in the air in 5 mins or less using this technique using a piece of lightweight rope and a rock. And you don’t even have to get it very high for good results.
Simply make a loop at the end of your rope and use it to choke the tip of the whip on the radiating (upper) dipole half. Throw the other end over a tree branch and hoist it up.. It’s that simple. Now pull your coax away on a 90 deg angle from the dipole and route it down to your radio.
If you’re operating from a high mountain with no trees, a lightweight support can be made from PVC or a short fiberglass pole. Never use a metal support for this configuration to avoid antenna coupling with your mast.
For my first test, I mounted the center of the dipole only 8 feet in the air (yes, the bottom whip was less than a foot off the ground,) and the results were astonishing to say the least.
The Vertical Dipole Antenna Performs
When I first turned the Yaesu FT-817 on and heard a loud signal on 14.270 Mhz, SSB. It was D44AC in Cape Verde calling CQ… I called him back and made the contact on the first call – “loud and clear” he said.. I was impressed! Not only was this a good DX contact for me, but it was also a new country for my DXCC 😉
From there I made contacts all over the US with just 5 watts out on the 817 hearing reports of “wow, you sound great for only running 5 watts QRP” and considered this antenna to be a winner. More testing will confirm, but I have no doubt that this is a worthwhile project for you if you like a light weight and quick to deploy antenna that truly performs, especially during good HF conditions…
Here’s what you’ll need:
A pair of Hamstick-style mobile whips for your band of choice (I carry two sets so I can quickly change bands by swapping whips. You can get these from a couple of different places. The Hamstick brand is no longer in business, but you can get the same thing through MFJ or Workman companies. And I’m sure eBay is full of choices too…
You’ll also need a dipole adapter. Mine is a trucker’s mirror mount that I found at a truck stop which will accept the threaded end of any Ham-stick style antenna (it’s the same thread size as a cb whip.) These are configured for a single whip, so I drilled and tapped another hole to screw in the opposing side of the dipole. You can also buy one that’s ready made from the MFJ catalog if you don’t have a drill & tap.
If you’re in an area with lots of trees, you’re in luck. Simply throw a line over a tree branch and hoist up your antenna. Just make sure that you can route the coax away on a 90 deg angle just like you would with a horizontal dipole. In other words, you don’t want your coax to dangle down along the lower half of the antenna. You might also consider a 90 deg coax connector to make it easier to route your coax nice and straight without bending.
Update: CQ World Wide SSB Contest With The Hamstick Vertical Dipole – QRP vs QRM…
Just worked some of the CQ World Wide SSB Contest from the field with the Yaesu Ft-817. After an impromptu decision to go out in the mountains to work a little bit of the contest today, the afternoon was already setting in, and I had a heck of a hike to get to a hilltop to where I wanted to operate. So I had to get moving.
After about an hour of hiking to the top of a beautiful wooded knob in the western part of Virginia, I got busy and was on the air in about 5 minutes or so.. (took some extra time to take some pictures and shoot a quick video.)
Now that I was on the air, the sun was setting – so I had to get busy. After only one hour of operation, I logged 24 DX contacts in 15 different countries on 20 meters SSB. Here is a map based on the maidenhead grid square locators for each of my contacts. And most of these were on the first call. I was ecstatic to be getting into these stations with 5 watts.
Once it got dark, I decided to pack up and head out. I had a smile on my face the whole way down the mountain knowing that this antenna is a winner. Simple, cheap, and easy to setup – on the air in 5 mins or less.. now that’s qrp in the field at its finest!
Please Comment and Share this article! 73 – Brian