Antenna - The never ending story
#1
We don't need big antennas for the range 30-300km

I have made lots of antennas and they all work well.
Important - Self-resonance must be high.

First I made a "reference antenna" 160mm Ø, 1mm, 14turn

Then one for a 75mm standard plastic tube
A piece of brake pipe and a 48-turn transformer on a toroid

The top antenna is isolated from toroid and is also used as an E-Field antenna - Perhaps the third channel in the H-Field antenna could be for E-Field  Idea Wink Rolleyes 

/Richo


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Stations: 584, 585, 2017
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#2
That's very neat and compact, could be tempted to play. Don't have any "scrap" brake pipe but do have some 2 mm dia solid copper wire, probably equal copper cross sectional area, which is the more important factor over dia? Presumably each loop is a single shorted turn, ie no gap?

Trying to think of a readly available source for 75 mm pipe and fittings. Pretty sure that UK waste water only comes in 32 40 and 50 mm before jumping to 110 mm. Roofing down pipe is 78 mm but doesn't have fittings with seals, stop ends etc.

Are additional H-field preamp boards available (bare or SM populated)? I'd not want to mess with the one on the main, installed, loops, just swapping Cat5(s) would be far easier and quicker.
Cheers
Dave.

Stations: 1627
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#3
I made a 1sqm loop like the small one you show on this page. And this is a really nice antenna, really sensitive ! I want to discuss this design with you. Cheers, 73's John F5VLB
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#4
This is a great design and very tempting.
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#5
@Richo has stated in the past that loops like this with a ferrite transformer are superior to any other design. But just how superior? Smile
Regards,
Mike W.
Stations: 1977, 2294
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#6
After reading this, perhaps I will make one of these for one of my stations to detect close lightning, as Richo says.
Regards,
Mike W.
Stations: 1977, 2294
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#7
@RichoAnd  Would it be good for participants with more than one receiver to have those short-range H-field antennas on one receiver and the other one with normal-size H-field loops? I cannot imagine why not.

(2019-08-03, 15:01)mwaters Wrote: After reading this, perhaps I will make one of these for one of my stations to detect close lightning, as Richo says.
Regards,
Mike W.
Stations: 1977, 2294
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#8
(2019-08-05, 22:39)mwaters Wrote: @RichoAnd  Would it be good for participants with more than one receiver to have those short-range H-field antennas on one receiver and the other one with normal-size H-field loops? I cannot imagine why not.

(2019-08-03, 15:01)mwaters Wrote: After reading this, perhaps I will make one of these for one of my stations to detect close lightning, as Richo says.

Mike, remember this part of what the system is:-

Blitzortung is an Experimental, hobbyist, educational, volunteer network,

Smile 
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Stations: 2100
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#9
Respectfully, I fully understand this. Why did you say this? I just thought that it would be great fun for me and other experimenters and hobbyists to try this. :-)
Regards,
Mike W.
Stations: 1977, 2294
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#10
(2019-08-06, 00:08)mwaters Wrote: Respectfully, I fully understand this. Why did you say this? I just thought that it would be great fun for me and other experimenters and hobbyists to  try this. :-)

Heh.. Smile   Mike, I'm pretty doggone sure that Dries was supporting your thought... One of the great advantages of having more than one station is the ability to experiment with one... as I do... Go For It, I think was Dries' hint... Lightning

Stations: 689, 791, 1439
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#11
Thanks, Mike and Dries. No hard feelings at this end! :-)
(You sent me a message, but I cannot find it, sorry.)

Dries, just put an order in for another receiver! Eventually, you'll get it.

Mike, have you ever thought of making a short range H-field antenna for one of your three receivers? I don't know about you, but this seems like such a wonderful idea!
Regards,
Mike W.
Stations: 1977, 2294
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