40m Loft Antenna

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Buick Mackane
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40m Loft Antenna

Post by Buick Mackane » 29 Jan 2017, 19:53

Right. I wanna get myself onto HF, The band that interests me is 40m. Now what can i squeeze in the loft that will cover that band ? The length of the loft is roughly 18ft. So a dipole is really out the question unless i zigzag it all over the joint. I was thinking about buying a 40m mobile whip and bunging that up, But before i go spending my hard earned is there anything i can knock up myself to do the job.


Cheers gents.

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ch25
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Re: 40m Loft Antenna

Post by ch25 » 29 Jan 2017, 20:04

You really want to radiate rf right into your body? lol
You can't have too many antennas...

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mercury888
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Re: 40m Loft Antenna

Post by mercury888 » 29 Jan 2017, 21:02

Allegedly one can run a random wire thru a 9:1 un-un to match to 50 ohms provided the wire length is not resonant on the band you want. I'm about to have a go at one of these. My radios are on the first floor so I'm to gonna manage a decent earth.

The issue is you need a decent length of coax to act as 'earth' (so they say) and can't use a coax choke, so quite how well it will work I dunno.

I have (well, will have) a fan dipole in the loft so far (only 6m right now but adding more) which the FT450D is happy with but it's as noisy as one would expect with all the other stuff up there.
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NightProwler
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Re: 40m Loft Antenna

Post by NightProwler » 29 Jan 2017, 21:19

I had a dipole for 40M running around my attic and it was terrible. Get it outside.
Shorter of breath and one day closer to death

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Re: 40m Loft Antenna

Post by Tigersaw » 29 Jan 2017, 21:50

If you are using a un-un it will have a hot and cold side. Hot side to your antenna wire and cold side as counterpoise.
experiment.. I gave one a go, hot side to the ex TV antenna (so a vertical piece of wire running up the chimney to a small top hat) and the cold side to the water tank feed.
It would match most bands 80-10, worked best on 80m and I had a few rag chews 100 miles radius

edit: most other antenna ideas I tried in the loft were pants. Had a bit of luck with a 6m bazooka dipole when the band was open, but thats about it.

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Re: 40m Loft Antenna

Post by kilimax » 30 Jan 2017, 14:27

There's a number of topics on the web that suggest different options for indoor or "stealth antennas" if you are stuck for space. Outside is always better but good results are possible with indoor antennas. If you have 18' (square?) to play with, there's room for a folded dipole and if you add a pair of traps, you would extend the number of useful bands. Another tried and tested design is a delta loop and again, you can fit that into the space you have. Just Google indoor 40m antennas.

Performance will be down on an outside antenna and noise could be an issue but you won't know until you try.

Edit**

Link to a useful website for antennas

http://www.dxzone.com/catalog/Antennas/ ... _Antennas/
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madman1027
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Re: 40m Loft Antenna

Post by madman1027 » 30 Jan 2017, 19:00

i went for a 40m loop just folded & bent to fit in the loft, it wasn't perfect but worked alright.

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Buick Mackane
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Re: 40m Loft Antenna

Post by Buick Mackane » 30 Jan 2017, 19:02

Thanks for the suggestions. Much appreciated. But i was hoping there might have been a quick fix, Something i could just chuck up and forget about, Don't have a lot of time at the min for antenna experimenting, But the info posted will come in handy at a later date when i have more time to muck about with antennas, The folding dipole looks interesting,



cheers

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Re: 40m Loft Antenna

Post by dxgtlswr » 01 Feb 2017, 10:14

Buick Mackane wrote:Right. I wanna get myself onto HF, The band that interests me is 40m. Now what can i squeeze in the loft that will cover that band ? The length of the loft is roughly 18ft. So a dipole is really out the question unless i zigzag it all over the joint. I was thinking about buying a 40m mobile whip and bunging that up, But before i go spending my hard earned is there anything i can knock up myself to do the job.Cheers gents.
Hello Buick!...I'm currently using A HF mini (monoband) dipole, Which just fits in my 15ft wide - balcony.
Working stateside/Canada with 10 watts no bother at all.

See the link below.

http://www.sandpiperaerials.com/product ... i-dipoles/

All the best.
http://www.mm6kha.uk



Cheers gents.[/quote]

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Buick Mackane
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Re: 40m Loft Antenna

Post by Buick Mackane » 01 Feb 2017, 10:55

Ideal dxg but a tad pricey. But definitely worth considering. Cheers.

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Re: 40m Loft Antenna

Post by jkb » 01 Feb 2017, 16:16

What about a long wire hidden behind your gutter?

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Buick Mackane
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Re: 40m Loft Antenna

Post by Buick Mackane » 01 Feb 2017, 16:33

jkb wrote:What about a long wire hidden behind your gutter?

iv'e purchased a 40m mobile whip, it'll probably be crap, but time will tell, kinda tempted by the short dipoles the guy above posted a link too. just wish i'd seen them before buying the whip. {bnghd}

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Re: 40m Loft Antenna

Post by dxgtlswr » 01 Feb 2017, 20:43

Buick Mackane wrote:Ideal dxg but a tad pricey. But definitely worth considering. Cheers.
Hello Buick!....Cheaper @ - http://www.radioworld.co.uk/hf-mini-dip ... r%20dipole

Karl,
73.

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Buick Mackane
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Re: 40m Loft Antenna

Post by Buick Mackane » 01 Feb 2017, 20:49

dxgtlswr wrote:
Buick Mackane wrote:Ideal dxg but a tad pricey. But definitely worth considering. Cheers.
Hello Buick!....Cheaper @ - http://www.radioworld.co.uk/hf-mini-dip ... r%20dipole

Karl,
73.

Roughly the same when you include postage, But thanks pal, Think i'll buy one.


EDIT my mistake radioworld is about a fiver cheaper :thumbup:

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