The QRPer Board

Hi Folks,

When out in the field using EFHW/Randon Wires how are you attaching the wires to the Balun's. Are you just stripping the wire at the end and winding it round the post, using banana connecters or something else.

I have found that when stripping the cables the wire will eventually break after a few outings because of the tension on the cable and the tightness of the post.. this obviously leads to shorter and shorter wire lengths, grrrs.. And banana connecters also break after a while.

What's the best solution in order to avoid the wires breaking. ( Unless of course you are all using very heavy duty wires which I doubt ).

Cheers Roy

I made a winder with unun mounted and wire attached directly to it via strain relief.
hope u can see it in picture.

top pic is 3 band trapped efhw

previous ununs just used alligator clip to grab wire

only time wire has broken was caused by dog running thru lower end

Hi Roy

My antennas are usually 26 or 28 gauge wire. I add 30 to 40 cm of heavier wire at the transformer end to compensate for the rough handling and bending it can be subject to. Remember this adds to your antenna length, so you have to subtract that length from the far end of the wire.

I tie a knot in the heavy wire on the transformer side of the splice. A string or rope tied around the wire In front of the knot can be run to a stake in the ground or somewhere on the table to take the stress of the wire. Then the end of your antenna is loose and needs no hard connection. A croc clip or just wrapping the wire around the post can work.

Your antenna wire doesn't have to be stretched "fiddle string" tight to work. My antennas droop a lot when up in the air. The one in the pictures is at least 5 years old and hasn't needed any maintenance at all.

GL n 73
Rick N8TGQ

for fixed ops one side of the antenna may be suspended to a rope tied to a weight, so that the antenna wire is free to slide, for portable one may use an alligator clip, if someone/thing trips over the antenna wire the alligator releases it

You didn't say what transformer you are using, or whether commercial or home made. I went looking at commercial ones online and none of them had a way of anchoring your wire to leave slack on the connection!
Some had a eyebolt to hang the transformer from. I guess you could loop your wire thru that. Or maybe add a smaller eyebolt near the antenna connection. I would even be worried about the coax connection if the coax is just hanging from it.
All the money they ask for their products and no strain relief attachment spots. Weird!

Considering how easy it is to build

https://vk6ysf.com/unun_9-1_v3.htm

I think it won't be a problem building one of them as desired

the "ground" goes to the counterpoise(s) or to ground stake, a small IP66 electrical junction box will host the toroid, the wire connectors and the coax one, a slightly larger box may even host both, the 9:1 and a guanella choke wound using a second toroid (same type/material)

I'm working on that exact idea - a housing with a 9:1 unun and a choke, and those brass connectors that are used for linked dipoles glued to the outside to connect the wires. I have a 35.5/17 foot EFRW as my primary home antenna, but I can have both 35.5 and a 29 foot wires for portable operations. It isn't fancy and it isn't original - it's a mashup of various similar designs.

One recommendation. Your design drawing has three holes along the length of each "arm" of the winder body. Weave the end of the radiating wire through the holes of one arm before making the electrical connection. You can do the same with another arm for the counterpoise wire, if desired. The 3-hole weave provides good mechanical strain relief to protect the electrical connection. I have had success with this method on my homebrew antennas.

Best 73 de Brian - K3ES

Brian,
I like it! Thanks.

Mike, KL7MJ

A suggestion, make the "box" hosting the 9:1 and choke a bit longer so that the two toroids will sit flat side by side laying on the bottom and not one over the other, also consider enlarging the sides a bit and having some rectangular slot holes at the sides, these will serve to host some velcro straps which can be used to hold the antenna wire (and coax if wanted) once wrapped and may also be useful to tie the unit to some rope or the like when operating; also ensure that the larger holes on the two flanges at one side can accomodate a carabiner, that will be useful too