Thursday, November 3, 2016

Building a Simple Top Band/80/40 Meter Antenna

Having the FTDX9000D has made me want to experiment when it comes to antennas, I want to explore the possibilities of the radio and so to do this properly I need antenna coverage of all bands. I'm pretty well covered except I've never really had a top band antenna or a 80/160 mix because like many amateurs I'm too lazy when it comes to trying to fit the size of a 160 antenna in to the garden. I know you can reduce the size etc, but as I said sometimes you just can't be bothered!

A while back when feeling more adventurous, I had built one and tested it, but I couldn't keep it hoisted up together with the W3DZZ as members of the "family" were not amused!
But now having the extra land has opened up my selection and somewhere within our new paddock will be an area devoted to my antenna testing with I might add full approval!

Digging out the old antenna from my shed I realised and remembered I had literally only tested it for a few days and then put it away. So really it needed retesting again to make sure everything was working OK.

Consisting of 24.99 metres of wire with two traps, I seem to remember this was a reasonable antenna that was pretty well matching the W3DZZ, but for either sentimental reasons or something else I left the W3DZZ up rather than this antenna. I can't for the life of me remember where I got the original idea from, but it must have been from the web somewhere. So I will continue to search and maybe get lucky to show the original plans.

I've been looking on the web and I think it was a 40/80/160 meter designed by G0ONX Len Paget.
Len is the same amateur who put together the W3DZZ 40/80 that I think is a brilliantly simple antenna that gives me great results. He uses coaxial traps that are very easy to construct and work extremely well.
Another amateur M0MTJ who altered Len's design states:
 " The Inverted L for 40m/80m is shown below is essentially one half of a W3DZZ dipole fed against ground using one 7.1 MHz trap. It's a very compact antenna and is simple to construct. It is most efficient, of course, on 80 metres and 40 metres, but can also be used, with an a.t.u., on 20m, 15m and 10m. "

(Click to enlarge)
Here's the basic 160 set up which is very easy to construct and looking at the picture above I realised why I chose this antenna as it fitted fairly well to the dimensions of my garden. The other reason was of course the simple trap design that I had used before on the W3DZZ so winding up some more coax was dead easy to do.
M0MTJ goes on to say:

"Adding 160m / Top Band to an Inverted L
The 160 metre Top Band can be added to this aerial by connecting a 3.5 MHz trap at the end of the 80 metre wire (where to monofilament joins the 6.55m section of wire in the picture above) with another length of wire on the other side, increasing the overall length of the antenna."

                        Find out how to do it here:

So in the next few days I will be raising the antenna back up on one of my scaffolding masts I have recently erected and see how the FTDX9000MP works on 160, I don't really want to do too much local stuff I would prefer a bit of DX, but we'll see!

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