The Doublet Antenna in Practice | Ham Radio

Peter, your timing is perfect. I have wanted to try a doublet for some time. I was worrying about achieving a perfect half wave feeder length at 90 degrees to the antenna, and had assumed that I needed to put the balun at the base of this and run the coax for the full horizontal run back to my shack. Your video shows how simple, easy and cheap this project can be. Thank you, I know where to buy the bits! Kevin, MW0KXN

I have a 40 metre doublet in my roof space, with only 8 metres out horizontally, I first took the feeder back to the shack then through a commercial 4:1 balun into my atu, I was disappointed with the result, my fan dipole out performed it greatly, I decided to use my own homemade balun instead, also cutting the twin feeder so it only hung vertically, then joining the coax at that point, it made a huge improvement, and I use it for every band 40-10, on 15 metres it is terrific, for an indoor antenna it's quite amazing.

Thank you Peter I have learned more from your common sense videos than any other source…….I love my doublet 21 meter legs fed by ladderline a 1:1 balun then coax into the house and into an mfj manual tuner. I can work it on 80 40 15 and 10 and when I get my standard Australian licence I will use it on 20. Because of a very small block of land I have a 90 degree bend in the middle and a near 90 degree bend halfway along each leg and it works fine I call it my crazy zigzag doublet…….I have worked every state capital of Australia , NZ and Fiji on 5w ………good luck trying to figure out the radiation pattern 😀.

Reminds me of the advice I had when I was first Licensed, nearly 40 years ago. GM3OXX told me to put up the longest wire I could, as high as I could, cut it in the middle and feed it with ladder line. I did, used a balanced ATU / Z-match, and worked loads of stations with QRP. Never had a house since that would allow the same set up. Keep thinking of a remote ATU to do the job. Thanks for sharing Pete.

Another great video with a number of ideas for making the doublet work in many different locations 😃👍!

Thanks peter, really great and clear advice on the subject, especially about off centre feed points...

Thanks for such a thorough video. I already have the requisite materials and was thinking of eventually erecting a doublet, but this gives a few more ideas as to how to fit it within my tight garden and get back on 80m in time for winter.

Thanks so much, Peter. These basic instructions are just what I need as a new ham. Bests.

Great point about being off center to avoid interaction with a metal mast. I pull the window line to a 4m wood post that is near the house, so the ladder line does not drop vertical, but comes off at an angle. Same thing only different. I must say, so far, of all the wire antennas that I have tried, the doublet is by far and away my favorite antenna.

Great video. I haven't had a doublet in 8-10 years, but I think it is time for another one as they are fun and highly flexible. My last doublet was a coax fed OCFD dipole that swaped the coax out for 450 Ohm ladder line. I had a blast with it until I got it stuck in a tree on a QRP outting and ended up pulling it apart. I ended up loading the rain gutter on the park pavillion to make contacts on 20m & 40m. I have picked up a few ideas that I will try on my next doublet. Cutting the antenna a little short to about 3/8 wavelength and feeding with a minimum greater than 1/4 wavelength of ladder line. Sweep the antenna. If one of the higher bands presents a particularly high SWR trim the feedline by 1/8th wavelength of the higher frequency. The past few years I have mostly used an 80m-10m EFHW for portable operation. It is easy to deploy and allows 80m NVIS which I am fond of for Ecom.

Hi Peter a very interesting video and well explained iv been using a doublet antenna for many years it’s so simple and works well I bring the ladder line down to just outside the shack where it’s connected to an sgc 230 auto atu which is flouting above ground as these is only a single wire connector for the antenna the other side of the ladder line goes to the ground of the atu then a short run of coax to the radio it tunes on all band no problem 👌

I tried the doublet on a visit back to the old house in Ireland, just used some single house wiring cable and some Plastic pipe fittings to assemble it. I had spare ladder line. It’s still laying on the grass across the field but I connected it up and massive signals appeared. Made a few contacts with FT8 and checked PSK reporter and there were 132 reports. The most distant was PY5EG on 40 Mts. I did not think it would work laying on the ground. I might try and sling up today. Once I tuned it on 40 the SWR was low on all the bands going up to 10 Mts without touching the controls on the ATU only 80 showed high SWR without Changing the settings. Mark EI4JD near Shannon

Just made and installed a doublet, 7'5m each leg, (2:5mm cable) and approximately 6 metre's of 450 line, terminated into a 1:1 current balun, then a short leg of RG8 into a LDG external tuner, Great on 40 , worked A6 on 12 SSB first QSO, and Italy on 20 , doesn't like 15 or 17metres... only 4 metre's above ground, but then I've QSY'd from Dorset to a inner Hebrides island... loving zero QRM again.. cheers Andy MM0###...PS about 20 metres of RG213 into the shack

I have a doublet. Originally it was a 40m long inverted V with 100ft of ladder line hanging from a 25ft flag pole. Oddly, it was difficult to tune on some bands. Based on a web site I visited, I shortened it to 110ft (55 on each side). Now it works better on most bands. It's confusing to me why shortening it would make it better, but I'm just happy it seems to work. The worst part about it is that the two legs are 90 degrees from each other, and one leg bends at the end of the fence and runs a few feet along the fence parallel to the other leg. I call it a "perverted V" antenna. I have a small back yard and a nasty HOA, so it's the best I can do.

A very good Friday afternoon to you all from Wellington Somerset

Well done!

Great video as usual… now I have a friend that runs his feeder line straight up the metal pole to the AntennA and he says it doesn’t make any difference it would be interesting to do an AB comparison between the ladder line being next to the Metal mast and the ladder line away from the metal Mast

Informative video

The days of open line are far from over. My situation: 2 x 59 ft doublet with open line all the way into the symmetrical tuner. Spaced with 4 inch rose clips and fed through the wall at the same spacing. From the end insulator to the tuner is one uninterrupted piece of wire, so no corrosion in the feed point. Worked 1250 miles on topband, 80 and above perform (much) better. Forget coax and the balun.

I feed mine in the middle but use a fibreglass push up pole. works great