I remember when it was very easy to get a phototransistor - you just filed
the aluminium top off one of those 'top hat' transistors. I forget the
number, but guess if you dragged that old 1960s transistor radio board from
out of the junk box you should be in luck... Neons can be found in an old
cooker switch...
Tim Makins, EI8IC
> ----- Original Message -----
> From: "K0FF" <K0FF@ARRL.NET>
> To: "Mark ." <n1lo@hotmail.com>; <towertalk@contesting.com>
> Sent: 25 January 2001 23:23
> Subject: Re: [TowerTalk] Static Charge field/strike detector reply de K0FF
>
>
> The current trough a neon tube would be too low to run a relay direct.
There
> is a version of the Vactrol that uses a neon tube, and it shines on a
> phototransistor, all sealed in a plastic tube. I have a few, or can get
them
> from Gateway Electronics in St. Louis .
>
> The photo resistor could drive a counter etc.
>
> Happy Homebrewing, Geo>KØFF
> http://homepages.dstream.net/K0FF
>
> ----- Original Message -----
> From: Mark . <n1lo@hotmail.com>
> To: <towertalk@contesting.com>
> Sent: Thursday, January 25, 2001 1:32 PM
> Subject: [TowerTalk] Static Charge field/strike detector
>
>
> > I seem to remember reading a post way back in the archives about a way
to
> > homebrew your own detector for charge fields that were strong enough to
> > become dangerous.
> >
> > It centered around using a sensing antenna of 10-20 feet of wire
connected
> > to one leg of a neon light bulb. The other leg of the bulb was connected
> to
> > the coil of a relay, with the opposite coil connection to ground.
Perhaps
> > there was a limiting resistor in series between the bulb and relay coil.
> > When the charge built up strong enough, the voltage would exceed 90V,
> ionize
> > and fire the bulb, which then began to conduct and fire the relay.
> > The relay was used to ground a telephone line and it was touted as
firing
> > reliably preceding and during nearby lightning strikes.
> > Anybody else remember this? Or was I watching the Travel Channel?
> Seriously
> > though, I thought it was on this reflector, but for the life of me, I
> cannot
> > find it in the archives. I thought I had saved it somewhere.
> > I don't remember what voltage the relay coil was that worked. perhaps it
> was
> > 110VAC?
> >
> > --...MARK_N1LO...--
> > Gloucester, VA
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