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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Station: 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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#12
Question 
After mulling @RichoAnd 's post, and seeing how poorly my stations perform when the lightning is very close, I would like to pick your collective and experienced educated brains about something.  Angel

In the spirit of Richo's (our esteemed antenna expert) post above, I am seriously considering reducing the number of turns on one of my 2 stations (1977) to less than 4.

At some point in the past, in the context of a one meter diameter wire H-field loop, Richo declared that " 3 or 4 turns is enough for a System Blue".
Well, I used 4 turns on both of my stations, thinking that more is better. Should I have used just 3 turns?
  • Would 3 turns be sufficient?
  • Or would just 2 or even 1 turn be best?

How do my 4 turn loops compare to the ferrite-core loops that most folks purchased from @Egon?
Do they output more voltage? Is the gain the same?


However, my station does not perform as well as some others when lightning is close, the vast majority of which are using the ferrite loops purchased from Egon. This is the case regardless of how I change the gains or other settings.

For various reasons, at this time I cannot build Richo's design above. Nor can I do a lot of trial-and-error.
Regards,
Mike W.
Stations: 1977, 2294
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#13
(2017-08-25, 09:08)RichoAnd Wrote: ... A piece of brake pipe ...

Please, exactly what is brake pipe?

"Brake pipe" is unknown here in North America. If you mean the hydraulic tubing used for automotive brake lines, it is all steel here.
Regards,
Mike W.
Stations: 1977, 2294
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#14
@Mike: station 2601 running with copper loop w/ trafo since a couple of weeks.
So far, the performance is good on close strikes but on long distance this performs not so well.
Clément
Stations: 252, 680, 733, 1440
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#15
(2019-08-28, 18:46)mwaters Wrote:
(2017-08-25, 09:08)RichoAnd Wrote: ... A piece of brake pipe ...

Please, exactly what is brake pipe?

"Brake pipe" is unknown here in North America. If you mean the hydraulic tubing used for automotive brake lines, it is all steel here.

Steel the world over for fixed brake lines I should imagine. Copper is rather soft... It maybe "coppered" to try and avoid corrosion problems.
Cheers
Dave.

Stations: 1627
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#16
(2019-08-29, 16:37)allsorts Wrote:
(2019-08-28, 18:46)mwaters Wrote:
(2017-08-25, 09:08)RichoAnd Wrote: ... A piece of brake pipe ...

Please, exactly what is brake pipe?

"Brake pipe" is unknown here in North America. If you mean the hydraulic tubing used for automotive brake lines, it is all steel here.

Steel the world over for fixed brake lines I should imagine. Copper is rather soft... It maybe "coppered" to try and avoid corrosion problems.

Thanks, that sounds logical, Dave. I was thinking that perhaps they use hard-drawn copper (or a copper alloy) with a thick wall.

But I kind of question its conductivity due to the possibility that most of the 16 kHz ELF signal would likely be flowing through the steel underneath the outer copper coating. But @RichoAnd is pretty expert on this sort of thing.
Regards,
Mike W.
Stations: 1977, 2294
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#17
Anyway, I am looking forward to seeing an answer to my question here. https://forum.blitzortung.org/showthread...2#pid21382
Regards,
Mike W.
Stations: 1977, 2294
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#18
copper-nickel alloy / about 85% copper...  and Richo designed the originals for aboout 30-300km range

Stations: 689, 791, 1439
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#19
(2019-08-29, 20:25)cutty Wrote: copper-nickel alloy / about 85% copper...  and Richo designed the originals for aboout 30-300km range

Hard drawn cupro-nickel is common over here in the U.K. I replaced all the mild steel pipes on one of my first cars with it, easily obtained from motoring suppliers.
RED Station: 878,   Flightradar24: F-EGLF1,  Open Glider Network: Aldersht2, PlanePlotter: M7.
Stations: 878
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#20
This is what I used to build my 38cm coils. Fits nicely inside the ferrite core mentioned in the antenna document.

https://www.homedepot.com/p/Everbilt-1-4.../203654086

I don't used them anymore, so if anyone in the US is interested, let me know. I switched them out for the 300mm CSS I build. 

Dries
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Station: 2100
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