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magnetic loop hf

26fb99
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magnetic loop hf

thinking of making one.anyone have any experience with these so i have a fare idea without delving too deep.any rules of thumb i need to know????

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yaesu FT857d,rmkl500,wilson5000,a99 (thats a real satchel of cack)/2element pubical quad(the BBq).split charger aux battery system.170a truck battery,mfj 941 versatune2
100percent mobile station

laters peeps 73s

Brent 26 Fox Bravo 99

31/Oct/2009, 7:06 pm

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mikefox whiskey
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Re: magnetic loop hf

I know some stations that have used these, they perform adequately and at low heights too, they are less susceptible to local noise and static as they work on the magnetic field, they have a very high current when transmitting so they need to be high enough so they cannot be touched, the main negative about them that I know of is that they are a bit tight to tune and need re tuned every couple of KHz.

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Patrick - MFW / 68 FB750

kenwood TS870s - Astatic 1104c Microphone - 54 meter long doublet - Multiband Delta Loop.

31/Oct/2009, 7:49 pm

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Hot Fusion
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Re: magnetic loop hf

I agree with Patrick.

Magnetic loops are a pain to keep tuning every time you move frequency even a small amount, and the loop tuning capacitor has to be a feindishly large and expensive device to be able to take the massive voltages developed across it when using higher powers, and it has to be properly housed to protect it from the weather.

In addition to that, I've yet to copy anyone using one that puts out a decent signal compared to a random wire/AMU.

Good receiving antenna maybe due to nulls and lower noise (possibly), but IMO crap on transmit.

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Andy - 26 FB107

31/Oct/2009, 9:02 pm

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26fb99
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Re: magnetic loop hf

sound.thanks lads.its finished this arvo with pics to follow,using a small variable so qrp for now untill i get a high voltage cap. http://www.standpipe.com/w2bri/source.htm
anyone got or know where i can get one of these in the uk???

its about 6ft tall,made from 1inch coax,lookslike a hoolahoop and the idea is to run it alongside the quad on the van for portable amateuer band use.took me about 2 hours to build.i just buzz off building stuff!!!

1/Nov/2009, 9:45 pm

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Hot Fusion
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Re: magnetic loop hf

Well done. emoticon

I'd be interested to know how it performs for you.

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Andy - 26 FB107

2/Nov/2009, 8:36 pm

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26fb139
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Re: magnetic loop hf

couple of the locals run capco mags and rave about em.
prefer a beam but if space & nieghbours are a problem well??

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18/Nov/2009, 10:33 am

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mikefox whiskey
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Re: magnetic loop hf

John FB193 has recently used a loop horizontally with massive signals out, I'm sure he would not mind sending you the plans if you got in touch with him.

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Patrick - MFW / 68 FB750

kenwood TS870s - Astatic 1104c Microphone - 54 meter long doublet - Multiband Delta Loop.

18/Nov/2009, 7:36 pm

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Hot Fusion
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Re: magnetic loop hf

quote:
mikefox whiskey wrote:
John FB193 has recently used a loop horizontally with massive signals out...

Yes, but he puts massive signals 'in'!

I wouldn't be surprised if he has set up his own nuclear power plant to power his radio station!

Joking aside, I did hear him using it the other night, and he was bleddy strong, so make what you will of that. emoticon

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Andy - 26 FB107

18/Nov/2009, 9:26 pm

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yamanx1
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Re: magnetic loop hf

quote:

.........................I wouldn't be surprised if he has set up his own nuclear power plant to power his radio station!..................................

Oh! those who remark in jest emoticon

Not quite nuclear, but a hydro power plant wouldnt be too far from the mark emoticon

No not kidding emoticon

Ask John for full details emoticon

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Foxtrot Bravo DX Group

18/Nov/2009, 9:58 pm

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Hot Fusion
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Re: magnetic loop hf

Come on then John - I'm interested in extra-mains power sources. emoticon