www.m3zww.com/antenna design

I have been asked by quite a few people about my portable hf antenna, so here it is.

It's a variation on an antenna known as an "Ikstick" and I find it bang on for a bit of portable work.

After trying various antennas the one thing I found was, there a pain in the arse!

If you are going to use a dipole you need to get the centre up high, and this means getting some form of mast, most commonly a fishing type pole. Then of course you need a couple of suitably placed trees, or something else to hold the ends up. The you need a tuner (either balanced or unbalanced depending on how you're going to feed it).

Ooooh and you also need a catapult or an arm like Arnies to fire the end support lines over that well placed tree or end support!

So if I need a support pole for the centre why not use the pole as the ariel?

Take one 7-10 meter fibreglass fishing pole (look in eBay under fishing whips).

Remove the bottom bung/cap, and remove the top section of the whip, (these generally have a small loop glued into the end of them).

Now take a length of 18swg multi stranded insulated wire, and cut it 100mm (or 4" in old money) longer than the total length of your fishing whip. So if you have a 30 foot whip cut the wire 30 foot 4 inches…….simple!

Feed the wire in to the top section of the whip, it will only go in a shot bit as the top section is to thin to allow it to pass right through. When it's in as far as it can go take a very sharp knife and cut back (small bits at a time) till the wire is able to pass through the top section. You should now have no trouble passing the wire through the top section now.

Put the top section back in to the rest of the whip, to stop the wire falling back down the vertical glue a small rubber fishing ledger stop on the end of the wire.

You should now have a vertical wire running through the whip, but is unable to pull through due to the rubber bead. And you should at the base end have about 4" inches hanging as a tag end.

Now take the cap from the bottom of the whip and drill a hole to fit a M6 bolt, and secure it in place.

On the base cap section you will need to drill another hole about 1"- 2" up the side of the vertical, make sure you drill through the reinforced section and not the fibreglass whip!

and fix it in place with some suitable nuts.

Now fix the driven element to the base bolt with a lug or spade end.

You can now screw the cap back on. And that's the driven element complete.

For the counterpoise coil you need a 7 feet length of 1.5" plastic plumbers pipe (the plumbers center is great for this and cheeper than the diy stores).

From the top measure down 14" and make a mark with a pen, this is where the winding starts from.

Take a 35 foot length of the same 18 swg that was used for the driven element, and start the coil winding from the 14" mark, but leave an 8" tag of wire.

You need to wind at around 1 turn per inch.

When you get to 2 feet from the bottom increase the turns per inch till all of the wire is wound on.

Add a turn of electrical tape every foot or so to stop the turns dropping or going floppy.

When you have a completed coil, cover the windings from top to bottom with either self amalgamating tape or electrical tape.

On the end of the 8" tag fit a lug or spade that will fit on the bolt that exits the side of the vertival.

That's about it on the construction work, all that's left to do is put the bits together add a feed line.

To mount the ariel I use a extending 3 foot bank stick (again from the fishing deptment)

Screw the bankstick into the gound and extend it to around 4-5 foot.

Clamp the driven element to the coil section with a couple of hose clamps, as a precaution against crushing the fibreglass I use a couple of ofcuts of the coil tube as reinforcing.

Now stand the completed vertical and coil over the bank stick

Now take your coax and pig tail one end and fix a lug on each tail (make sure the lugs fit on the bolts!)

Roll your self a coax balun of around 8 turns of 6" and tape it up.

Connect your pigtails to the antenna, driven to the bottom bolt, and earth to the side bolt along with the coil tag.

As a word of caution run the coax away from the antenna at a right angle for at least 5 foot, beacuse if you don't rf will find its way back to you and your radio, and it tingles bad!

All that's left to do is connect your radio and a small atu and your ready to work that dx from /p.

Dose it work is the next question, oh yes!

I have had excellent results from this antenna running just 5watts from an FT817, on the lower bands it works great for inter Uk work, and from 20 up its very good for dx.

The total cost? I made this bad boy for £23 can't say fairer than that.

I hope if you build one of these it works as good for you as it has for me.

Top Band to 10 Meters

This is a really simple antenna for getting on the lower bands (and 20 to 10 in NVIS mode!).

Slot together some lengths of Ali tubing to form a vertical element. Any length between 25-40 feet will do, but the longer the better angle of radiation will be on the lower bands.

I personally use the full 40 feet.

Sleeve the bottom 3 feet in PVC tubing and fix in place with an epoxy resin, but cut a small square section out at the bottom on 1 side only. In this cut out section drill a hole through the vertical element, and fix in place an M4 bolt with a suitable nut.

With a couple of mast to mast clamps secure the vertical to a stub mount driven into the ground. (I use 2" scaffold lengths, about 5 feet long), making sure your cut out section is pointing at you not the stub post!

Tightly secure one end of a length of insulated #16 swg to the bolt at the bottom of the vertical, run it back to the shack avoiding ground contact (I pined mine to the fence about a foot up). The length of wire is not critical, so you can site this antenna at any distance from the shack, but don't let the wire come in contact with the ground or any metal objects.

To tune this simple aerial you need an LC tuner, and they are simplicity them selves to make.

You will need….

1 500pf tuning capacitor

1 PVC tube 5" x 2"

1 6" x 6" x 1" piece of wood (Oaks nice, pine is cheaper!)

1 3" x 6" Aluminium (Back plate for SO239 and binding posts)

2 Insulated binding posts (red and black or what ever you have spare)

16 swg enamelled copper wire

16 swg insulated

The following diagram shows just how easy it is to make

(right click image and view as)

The coil (L1) is wound with 38 turns @ 6 turns per inch. You could add a wafer switch to the tuner, and then solder the coil taps to the switch for band selection, but I use a "flying lead" with a fat croc clip on the end. (Make sure it's well insulated though!!)

With the tuner now made it's a simple case of connecting the vertical section to the red binding post and to the earth section you will need 1 tuned radial for each band of operation.

160 m 123'.00"

80 m 63'.00"

40 m 32'.6"

30 m 23'.00"

These radials like the driven wire should be placed above the ground by an inch or so.

You can add radials for the other band of 20 and up, but then the antenna goes into NVIS mode, for dx this is not much cop, but for local work would be very useful.

Now load it up and work some dx!

Right so here it is..........................

This is so simple to make, even though it looks like a mega job.

Using the following formula....

1005/f for the driven element

1030/f for the reflector

Cut your self to lengths of wire....I used good old red and black 12volt power supply wire. I found the

10 amp multi stranded to be spot on.

Don't use uninsulated wire!

The next job is to attach the loops to a frame in a triangular formation.

What type of frame you use is up to you, I had a box of 7m fibreglass fishing whips to hand

So I used these. Don't use Ali spreaders or you will be in all sorts of bother, you'll have mutual inductance, and a very live structure!

You could use bamboo, but its heavy compared to fibreglass.

But the choice is yours......

The top boom is an ali pole 2inch diameter and just over 10 feet long; this allows you to clamp 2 smaller 6 foot ali poles to it using mast to mast clamps to it giving 10 foot between the elements.

Don't use a boom of bang on 10 feet or it won't tune as well!!!

Lucky for me that the fishing whips with the bottom 2 sections removed slid snugly over the ali spreaders. (Also remove the top sections of the whip, as they are to thin to be of any use in this project.)

So now you should have what looks like a 2 element beam, with fiberglass spreaders.

There is no need to fix the spreaders to the supports as they will be held firmly by the loops.

Starting with the reflector and with electrical tape, tape the loop to the spreader.

The length you need is 26 feet across the reflector spreader.

The easiest way to do this is to fold the wire in half, and start from the middle and work your way to the tips, tape it every foot. This has now trapped the spreaders in position (see no fixing required!)

Now do the same for the driven element, and the length required is 24 feet.

Hoist this bad boy in to the air, I use a 12 meter push up mast, a thick walled ali jobbie with a top section of no less than 1.5 inches, any less and it will fold!

For the bottom boom use a wooden broom handle 5foot 6 inches long.

Screw in a metal "O" ring on the reflector end, and connect the dangly end of the reflector to this, (I soldered it for a good connection)

Job done, one full loop, this loop won't require any adjustment…..

For the driven element I used a small plastic project box, for making the connections.

In the top of the box I drilled 2 holes 2 inches apart, to allow 2 m8 bolts to be fixed through and held tight with some nuts.

Don't fix this permanently to the bottom boom yet, just tape it approx 5 feet from the reflector "O" ring, (bolt to ring).

Fit an M8 lug to each end of the driven element wire, and then clamp to the M8 bolts that stick out of your connector box.

Now before you clamp the bottom boom in to place gently apply some downward pressure to the boom to pull the loops in to shape, your looking for a nice triangular shape, and clamp it tight.

If you cut the loops right they should resonate on your desired part of the band.

You could check with a dip meter on the driven element, by putting a 1 turn loop of copper wire across the bolts and tuning for the dip.

The copper loop will help inducting into the meter, but don't forget to remove it afterwards!

As I said earlier the reflector won't need any further tuning as long as you cut it to correct length using the formula.

I feed my loop with 75ohm twin feeder.

It's advisable to connect your feeder on the inside of the box when you fix your bolts in place, other wise you'll end up taking it apart to do this, as I had to….. Doh!

Now connect the other end of your twin feeder to your atu.

Tune your radio to your desired frequency and apply a little RF, (have your atu in bypass mode) and check the swr.

If you calculated correctly your swr will be no higher than around 1.1 to 1.

If yours is higher move the connection box either closer or further away to the reflector, (that's why you don't fix it permanently to start with)

When you are happy with your swr fix it permanently to the bottom boom.

And give it some protection from the weather, I use spray on tape in a can

If you can't get the swr down enough check your calculations, and make sure the driven element isn't shorted.

Well that's about it……..

A 2 element delta beam that requires no silly matching system, and as a bonus, if yours is cut for 20 meters will also work as a double wave length delta beam on 10 meters with no atu tuning required.

Mine works with fantastic results on all bands from 20 - 6 meters with an atu (I use a 949e)

The best thing is it can be made for peanuts, I already had the mast, and various bits of tubing laying around, so basically the cost of the wire elements, and a plastic box.

It will give you better performance than a tribander, with them lossy old traps.

It's also a lot smaller than a mono bander.

It's less visible than a standard quad, and doesn't require multi element wires and ¼ matching stubs for each band, but will give you the same gain.