Re: Small garden Antenna for HF bands
Posted: 25 Jan 2013, 14:08
I have a brand new Hustler BTV6, I don't think I will ever get around to using it. Any good to you Paul? I'm sure we could do a deal if you like
Feeding an unbalanced antenna against an earth rod just doesnt work. That antenna would be so much more effective with proper ground radials, even if it was just one resonant for each band and on the same side. Inverted L's do seem to work very well for what they are if done right.Monsta wrote:
and for longer bands the inverted L for small spaces..you can get 40/80 out of these puppies and many hams work the world on these and swear by them ...they are sadly slighly directional on their lobes ..so you need to orientate them correctly, ideally you are looking at (as you know) NNW-SSE or NNE-SSW
http://www.clive.wankling.dsl.pipex.com/l.html
none of the above are "compromise" antennas, full of hats, traps, coils and all that other bullshine trickery that means you are not getting bang for buck and WASTING all your power heating hardware ...and thats why you hear about these QRP guys talking the planet on a wire ad 10 watts ...(makes you sick). Also none of the above require multiple grounding wires / RF earth webs ..(except for the copper rod)
i have seen monstrous HF verticals that are utter tripe without good RF arrays, to resonate with and you might find your wife gets a little upset with you burying 20 wires in the lawn ...I mean it makes all the difference ...but by god its a pain in the prostate without a big garden ...
Do it!
I don't think the chap who wrote the article understands where his return current comes from:NoiseBoy wrote:Feeding an unbalanced antenna against an earth rod just doesnt work. That antenna would be so much more effective with proper ground radials, even if it was just one resonant for each band and on the same side. Inverted L's do seem to work very well for what they are if done right.Monsta wrote:
and for longer bands the inverted L for small spaces..you can get 40/80 out of these puppies and many hams work the world on these and swear by them ...they are sadly slighly directional on their lobes ..so you need to orientate them correctly, ideally you are looking at (as you know) NNW-SSE or NNE-SSW
http://www.clive.wankling.dsl.pipex.com/l.html
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Do it!
Most of it doesn't come from his earth rod, but the coax feeding his wonder antenna, tsk tsk tsk.Because of the rain and soil blessing, a good r.f. earth is assured with only a single one metre long earth rod.
crusty wrote:Is that plot for a base-fed? If so, run that same antenna @ 40 and 10m. Base-fed inverted L's get goofy as a multiband. The frequency at which it starts to resemble a cap loaded vertical is a build consideration.
The antenna I modelled was a single band 80m antenna, if I find the time I'll have a go at modelling a trapped version, it would interesting to see the results, but as I'm now on my iPad I'll leave until another day. Of course patterns change dependant on the radial system employed, with the antenna above I purposely modelled it with absolute minimum ground in an attempt to replicate the article.crusty wrote:I read an article where the author got improved results on higher frequencies using a single trap. Can't recall where I saw it though sadly.
What do you use to match the antenna on 20m?uk197 wrote:I have a tiny garden and use a 10m tall fibreglass fishing pole with a wire up the middle, random bits for radials, its a nice 1/4 wave for 40m (no tuner required) and tunes up nicely as a 1/2 wave vertical for 20m too. Its pap on 80m, but I've worked the world on 40 and 20 with it.... I have a lot of time for verticals, they seem to be deaf to europe and great for DX.
MFJ auto-tuner. Oh I'm also quite anti-balun/unun toonorthern35s wrote:What do you use to match the antenna on 20m?uk197 wrote:I have a tiny garden and use a 10m tall fibreglass fishing pole with a wire up the middle, random bits for radials, its a nice 1/4 wave for 40m (no tuner required) and tunes up nicely as a 1/2 wave vertical for 20m too. Its pap on 80m, but I've worked the world on 40 and 20 with it.... I have a lot of time for verticals, they seem to be deaf to europe and great for DX.
I was interested as the impedance of the antenna will be very high on 20m, where it's a 1/2WL, sometimes tuners can struggle to match the high impedance, do you have a long run of coax and what type?uk197 wrote:MFJ auto-tuner. Oh I'm also quite anti-balun/unun toonorthern35s wrote:What do you use to match the antenna on 20m?uk197 wrote:I have a tiny garden and use a 10m tall fibreglass fishing pole with a wire up the middle, random bits for radials, its a nice 1/4 wave for 40m (no tuner required) and tunes up nicely as a 1/2 wave vertical for 20m too. Its pap on 80m, but I've worked the world on 40 and 20 with it.... I have a lot of time for verticals, they seem to be deaf to europe and great for DX.