Sota Portable Antenna

Well after testing and getting this Home brew dual portable antennas to work and tested on G/DC-003 with good results. I have now done bit of write up on the build and hope this may help others to make there own portable antennas and experiment. As I have done and get the satisfaction of getting it to work and making contacts off an home brew antenna. Even more so special making a first contact off the antenna to the other side of the world into VK5PAS on 10w on 20m.

The Home brew dual portable antenna
:grinning: 1/4w Vertical / 1/2w inverted L for 40m

Dead easy to make antenna

The 1/4w 40m vert portable wire antenna that requires ACU tuner
But tunes in ok on 80 40 20 15 and 10m
On a 8m telescopic fishing pole fibreglass

First of all cut triangle fair size and drill out the holes at each corner to take the support cord and a 22mm hole in middle. So it slips down the pole about just over half way. This is made from an old plastic chopping board strong and light weight.

Cut wire at least 11m long to make up 1/4w on 40m brought from Sotabeams cheap lightweight and plenty on reel if wire is broken to replace it.

This picture shows how the support triangle is in place and the shortening coil sits on top of it allowing certain length of wire to reach the 9:1 Unun below and enough to reach the tip of the 8M pole with at least 3m wrapped around the waste pipe but not too closely to each other the wires that is. Another diagram is below to demonstrate this.

Cut the 42mm waste pipe to about 25cm long put in two holes close to each other top and bottom.

Feed the wire though the first bottom holes so you have enough wire to reach down to the Unun you be making next. Not tight but not enough to dangle on floor. On the 42mm pipe start wrap around it in coil fashion but at least 1cm apart the wires till you reach the top. BUT thread enough wire through the top to reach the tip of the pole. Whole idea of this is to lose 3m of the wire so it hangs from top your of your squidgy pole and the slack is taken up by the centre coil pipe tape down to stop it flapping about. Now add or solder ring piece on there so it can go onto the 9:1 Unun winged nut section and make up enough cord to give good support to hold antenna up.

Simple,s one 40m 1/4w vert antenna portable, don’t forget your tuner :grinning:

Now the UNUN 9:1 follow the You Tube video

One torrid ring T200

Using three wires 18 gauge copper wire solid about 1m long

Wrap around the T ring as video shows 8 turns but do mark ends so you know which is which on wires when coming to putting into box and where they go and also clean off the lacquer off ends, so get good soldering ends joints.

Now you have a box drill hole in top for the M8 bolt and wing nut and place antenna wire and nut on. RIGHT M8 bolt is for the counterpoise wires and below that is the PL female plug for your Coax feeder. Again follow the video for where wires go. Note how i passed my wires through the box again on rings soldered terminals

How you mount this is up too you

Box it in a water proof box and do what I did with simple bolts M8 and wing nuts for the antenna outlet and on side again for counterpoise and of course the coax connector

Counterpoise can be another length single of wire again 11m long again with soldered ring on it.

And Bingo, one portable 1/4w 40m portable antenna easy to put up and down and put away.

There’s also another version you can do is the 1/2w inverted L do as same as above BUT the final length run off the top of the squidgy pole and away to some kind connection support keeping it off the ground an old tent support poles will do as there collapsible via an dog bone insulator.

Was rather fun in making this dual antenna system reason why as if not a lot of room run the vert. If room run the L version as its easy to interchange antennas while out on summits or just portable. But more fun when the contacts come rolling in off them antennas :smile:


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Please, Karl, edit your post to remove the leading spaces from the beginnings of the paragraphs. That will get rid of the horizintally scrolling text windows and put the text in plain readable blocks instead. Thanks.

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Thanks again, sorted now.
See why it has happened in first place now. :flushed:

sorted :slight_smile:


That’s it. Much better! Only one more to fix. Thanks. :slight_smile:

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…and all sorted. Good write-up. :slight_smile: