[ARC5] Seeking Extinct Wire

[Mike Feher]

Dave – It looks like there is adequate interest to justify keeping your progress with the maggie on here. I have never tried any of mine. Intended to but as the saying goes “never got around to it”, HI. At this point I do not know if I can help you any more. Right now none of my magnetic detectors are accessible as I just have way too much other stuff around them and I cannot get close to any. I do not believe that the wires need to be insulated since a whole small section is magnetized at once and depends on the nonlinearity of hysteresis for detection. The main reason transformer laminates are insulated is so that they do not form a shorted turn. I believe the reason of using many fine wires was to make the loop flexible and add strength. Marconi offered replacement loops. There are several YouTube videos showing magnetic detector that were home built. Wiki also has a decent explanation. I will ask some friends who may have more insight into the wire construction. Keep us posted on your progress. 73 – Mike 

 

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell NJ 07731

908-902-3831

 

From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> On Behalf Of David Stinson
Sent: Friday, May 30, 2025 10:16 AM
To: Mike Feher <n4fs at eozinc.com>; 'ARC-5 List' <arc5 at mailman.qth.net>
Subject: Re: [ARC5] Seeking Extinct Wire

 

Thanks for this valuable info, Mike. 
I note from the photo that the iron wires of the band 
appear to be twisted together into a cable configuration? 
I had read that the wires were not wrapped around 
each other, as the twist would caused the EM field in
individual wires to phase-cancel (like a twisted pair)<
but rather layered to act like transformer laminations 
(thus the insulation)  Have you tried yours for function?  

The one I have is a home-brew which came with 
steel wires that were twisted together
into a cable and painted with some kind of 
gray paint.  The coils and magnets are good, 
as are the lo-Z headphones, but the unit 
has no output, unless one stuffs volts of RF
into it, so that what one hears is just 
non-linear high-level leakage.
The only thing I can see which looks "off"
is the wires.  This one is a "demonstrator"
which has a hand crank on the side. 
I mean to install a proper
clockwork, but not until it is functional.

I had this crazy idea of trying to extrapolate 
the real, practical sensitivity of the "Maggie" 
used on the RMS Titanic, because I had 
some doubts about some of the claims
made for receiving the ship's distress 
calls far inland, or even at modest 
coastal stations.

But then I found the ship antenna technical 
specifications: a center-fed 
Marconi "T" 160 feet tall, with four "top hat" 
capacitive-loading horizontal wires 400 feet
long, the other capacitor plate  
(ground plane) a zillion tons of steel 
floating in thousands of miles of salt-water. 

So... OK.  You probably could have heard 
them had McBride sparked a 12-volt battery 
across the antenna.
But I still want to get this "Maggie" to work.

TNX OM ES 73 DE Dave AB5S

On 5/30/2025 7:31 AM, Mike Feher wrote:

Dave – I believe the originals were spot welded.



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