Radio Preppers

General Category => Antennas => Topic started by: solaris0121 on January 24, 2019, 03:53:40 AM

Title: Tent Pole antenna - could it work ?
Post by: solaris0121 on January 24, 2019, 03:53:40 AM
I do a bit of wild / ultralight camping with a mate of mine and have been thinking about antenna solutions when up on the hills.  I got to wondering, if I had a small QRP CW rig in my bag, but no way of setting up an antenna, would the metal tent pole tune up for emergency use ?  Imagine you are caught in a snow storm on top of a mountain and have to get into your tent quickly......

My tent has a single folding aluminium lightweight pole, about 9 feet long, that arcs from one end to the other, im sure a Z Match type tuner would tune it up ok.... although it wont be particularly resonant so close to the ground and being so short.  But who knows ?  You only need one person to hear your distress call.

So if any of you are off camping, be sure to give it a try and report back.... im off in a few weeks hopefully to North Wales and will give it a little try.  Possibly worthwhile as an experiment.
Title: Re: Tent Pole antenna - could it work ?
Post by: gil on January 26, 2019, 03:53:42 AM
Certainly. You would use a 9:1 UNUN to get the impedance down to where the tuner can handle it...

Gil.
Title: Re: Tent Pole antenna - could it work ?
Post by: solaris0121 on January 27, 2019, 09:04:35 AM
I was wondering if one of those Z Match type QRP tuners would work without the UNUN ?
Title: Re: Tent Pole antenna - could it work ?
Post by: gil on January 28, 2019, 01:26:33 PM
The thing is, if you put the tuner at the radio, you'll have high cable losses. With the UNUN you lower those. Not as good as a 50-ohm match but better. Try with the tuner at the wire, but I would use a UNUN...

Gil.
Title: Re: Tent Pole antenna - could it work ?
Post by: Jim Boswell on April 15, 2019, 07:52:49 AM
Gil has a point about the end-fed antenna. Are you camping where there are trees? Just take a rock, tie a good cord on it and throw the rock across a tree limb. Hoist-up the end fed antenna, add a short ground connection and you are set. On 20 meters I have done low power SSB with a dipole about 5 feet off the ground. Get that same antenna 20 feet off the ground and a lot more people hear me. Antennas work much better when they are higher and longer!