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Re: Simple radio signal



OK

Here's my ha'penny's worth (some would say farthing):

Zap probably and H. H show that the effect will be much enhanced if the
transmitter is connected to a dipole antenna. The antenna not only couples the
energy better to the impedance of the "aether", but also acts as a resonant
circuit to narrow the frequency band (Spark transmitters are notoriously broad
banded.) H. H. used two metal spheres as a spark gap and as the capacitance in
series with the rods that formed the dipole ant. Thus:

---------------0 0---------------

His receiver (as one of you described) was a large ring broken by a double
sphere spark gap. The xmitter worked because the Ouidon coil has a high
inductance, so, though it's in parallel with the Ant. (Spark gap), it didn't
short it. A VDG will also not short it, though I've never heard of this use.
To get best (or any) result tune the Ant to match the resonant freq. of the
ring. I'm ancient so I'd use a GDO (grid dip oscillator) There must be more
modern methods now.

Incidentally, Cenco or? sold a system where the gap is replaced by a double
triode. The dipole is about 1.5 M in length and formed the "tank" circuit (just
as it did for the spk. xmitter). The receiver was also a stiff wire dipole with
the gap replaced by a flash light bulb. With it one easily shows polarization
and field reduction with distance (Just as did H. H.!)

bc

P.s I have some where a copy of some of his (H. H.) notes with drawings of the
apparatus, etc.

Owen von Kugelgen wrote:

I want to create a simple demo of transmission & reception of radio signals.
Any ideas? The spark from a VanDeGraf generator should send a signal that
can produce a small spark at a receiver (simple antenna with gap). How might
I construct this "receiver?

Thanks in advance.
Owen