Idea, lets have a "dont laugh at us" antenna club.

[CJay]

After a couple of months planning and neogtiating, my 'shack' goes up tomorrow at the end of a 22 metre long garden.

Once it's all wired up and I have finished the thermal insulation there will be a fishing pole supported longwire running back to the furthest point of the house I can find, I'm hoping to be able to suspend roughly 22 metres of wire at approximately 7-8 metres above ground, that'll be the only 'sizeable' antenna I will be able to use (though I reckon I can get away with a 2M/70CM vertical as well) so stand by for pictures of woeful antenna fun.

[cdev]

Thats just great! I hope it works out for you- 7 or 8 meters high is pretty good..

So you will be able to raise your antenna up easily with a telescoping pole..that will be a good way to go..

[apelly]

Not to de-rail the topic, but...

I am in a temporary house with a small garden and no trees (maybe 3Mx10M, but whatever I decide on will likely have to be in a corner.). I've been putting off setting up a semi-decent antenna.

What would you guys recommend for a temporary, easily erected/dismantled HF antenna?

I could also do with something functional for VHF/UHF.

The main issue I can't get my head around is how to get some height without spending $$$ on something temporary.

[cdev]

Its not the height so much as the angle of radiation.. on HF..

A magnetic loop is your only real choice but the cool thing is the performance as far as angle of radiation can end up being quite good even without any real height, (especially if you have some kind of counterpoise right below it which also doesnt have to be super large..

also it doesn't have to be heavy to get good performance, just "thick" because of skin effect.  So its perfectly fine to get say an octagon made with plastic pipe or even a pool float and wrap it with a spiral of *wide* copper tape - the most important thing is the width of the conductor, and low resistance in the transition to your receiver or transceiver. You can use a coupling loop or a gamma match or some kind of transformer..  See https://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm for the definitive document on coupling methods.

 If you can get a good electrical connection it should tune right up with a reasonable value variable cap and give you good performance.  The spiral is to give you the effect of a longer loop in a smaller space.

This is kind of what I mean..

http://www.hlmagneticloopantennas.com/

I've built lots of magnetic loops and they often work extremely well for receiving.

[apelly]

A magnetic loop is your only real choice...

Thanks for the resources. Also found this: http://adam.curry.com/enc/20150119092647_article-antenna-mag-loop-2.pdf

That's my weekend cut out for me...

[cdev]

When I said "its your only real choice" I was basically saying the first thing that came into my head. There may be other better choices, just to the best of my knowledge this is I think the best thing you could do in that space. Your point about height is a good one.. If you could go straight up and could put out some radials some distance beyond that space and tune it with a tuner at its base or use a unun there you might do better with a vertical.. perhaps.


The difference is that antenna would be very visible and this one might not even be noticed, plus you could bring it indoors when you weren't using it.

[apelly]

I was basically saying the first thing that came into my head.

Gave me a good clue to be going on with though!

Alas, it won't be this weekend. It's going to take a while to get hold of a decent cap.

[tautech]

This thread reminds me when I was setting up a telemetry link for RF control of a mains powered pump some 500 m away when I asked a knowing buddy about antenna design.

He recited this story of his Yagi design and extremely careful antenna construction for UHF TV reception. The best of materials were selected to ensure no dissimilar metals in common contact, stainless fasteners, custom made insulators and all Yagi design parameters met...so he thought.

Reception was pitiful for the trouble taken, in fact rat shit were his words.

They settled for a spoked bicycle wheel on a pole ! 

[NivagSwerdna]

I got one of my first contacts using a https://en.wikipedia.org/wiki/G5RV_antenna strung in the garden... voice from UK to Oz.  The other guy had a better antenna.