*WARNING: OFFER EXPIRES END AUGUST 2017
I listened! Some of you wanted an economical bare-bones system without all the little “bits”. Here it is!
This is the listing for the “Bare-Bones” system which includes the pole and the 4 water-jet cut plates only. For me, this was the difficult part of the DX Commander’s journey into production. I hand-made a number of variants before finally settling on this design. For the serious hobbyist, these parts are the difficult bits to make. Just add some crimps, some wire, paracord and shock-cord to keep the tension on your element and you’re away. A couple of jubilee / hose-clamps might assist in keeping the lower radiating plate from listing up with element tension – I used to use electrical tape to keep the cost down. If you have some shrink-wrap and 6mm bolts, then you will be complete.
I’ve managed to keep the price very keen by packaging the pole and the plates in the one shipping unit and also saving a substantial amount of my own time by not having to measure out and bag all the little bits and accessories etc. So you get a first-class product at a cracking price.
- Ground Plate
- Radiating Plate
- Guy Plate
- Upper Spreader
- SO239 with flying lead and fork connector
Just add 6mm nuts and bolts, some wire and paracord and you’ll be 90% of the way there. Some small shock cord and a couple of buttons will let you erect and dismantle easily.
In the spirit of amateur radio, it’ll allow you an element of “build” fun and creativity too.
I run one of these myself with 40m, 30m, 20m and 17m elements. The 15m band is also catered for by means of resonating the 40m antenna and using a “boomerang element foldback” to achieve a pseudo 5/8ths for 15m band. No tuner is required and the far field patterns are excellent for DX. I achieve fabulous results and the DX Commander poles and sub-systems have quite a following. I have really enjoyed deploying this antenna for /P and holidays. I even run one in my garden without any ATU via an amplifier. Great fun.
The DX Commander vertical is based on the same technique as a fan dipole. Effectively a number of elements present themselves to your load and self-select to achieve efficient quarter-wave performance on all bands, according to which quarter-wave elements are installed.
Achieving gain on 12m and 10m is simply a matter of clicking in your ATU on your radio since without appropriate quarter wave elements, you will find the SWR is only about 3:1. Quite reasonable. It will also tune on 6m and although the far field pattern is not perfection, there is gain and you will achieve Sporadic E contacts. Alternatively, install 10m and 12m elements too! I’ve always thought a 3/4 wave for 10 might work but I’ve never tested the idea (yet).
Here are some example QSO recordings using this antenna: http://www.m0mcx.co.uk/audio-clips/
Radials: There is much baloney surrounding the topic of radials. The bottom line is that the difference between around 15 radials and 120 radials is less than a dB or so. Further, more and shorter radials are better than fewer and longer radials. I have written a simple-to-understand paper on this subject found here: http://www.m0mcx.co.uk/wp-content/uploads/How-many-radials-do-I-need-for-a-vertical-antenna.pdf
Personally, I’ve gone down a half-way house route with 35 x 4.5m long radials in bunches of 5. These are crimped and soldered to a fork connector in bunches of 5 which means I effectively only have to make 7 connections when I set up.
You will need to invest in a relaxed “build day” to make your first build and solder your connectors on and measure out your element lengths to make sure the antenna is repeatable so that in future, you can erect within 20 minutes and pack away in a similar time. Tip: Tape the ends of the radials together when you pack away so they unravel fast in a single line without tangles.
To keep the price down to a bare-bones budget, I am supplying on this listing, just the pole and the 4 x plates (aluminium ground plate and driven plate and nylon guy and upper spreader).
There’s quite a following of DX Commander users out there, so join in and enjoy having a truly efficient multiband antenna. And don’t worry if you break it in a school-boy accident (walking on it, driving over it etc), I do replacement warranty poles for 66% of eBay’s price (inc shipping price). Of course a manufacturing error or fault is a different matter.
My latest Hints and Tips build tricks film found here: https://youtu.be/JX-weSomX3g. There are lots of films about this system on my channel.
I have measured the element lengths (not including the fork connector) and you will have a no-tune antenna if you follow these lengths:
17m – 3.83m + 6 cms foldback (for the heat shrink)
20m – 4.88m + 6 cms foldback
30m – 6.74m + 6cms foldback
40m (and 15m) – 11.06m (foldback about 1.25m from top of pole and back. A sort of linear-loading / boomerang match)
If you want to tune 15m higher in the band, cut about 15 cms off the 40m element. It will make only negligible difference to the 40m band SWR curve but will raise the 15m band SWR by around 100 KHz.
Buy with confidence. My ebay rating is 100% and I’m proud of that so if anything isn’t up to scratch, I’ll “do the right thing” and fix it for you. This is a hobby business with low margins, but I thoroughly enjoy making this gear and testing it out so that you get a great experience – and I get exactly the gear I want in the process.
If you like DX Commander products, track down the DX Commander pole on eHam and leave a review there too.
Thanks for all your support chaps. Kind regards, 73 Callum M0MCX.