10 hertz radio transmitter or nuerophone
John Winters
10 hertz radio wave transmitter? Without giant components?
Anybody know what a nerophone (spelling?) is or how to build one?
Just curious.
John Winters win...@pdn.paradyne.com or pdn!winters
Roy Smith
> Anyone care to say how they would go about building an A0 (continuous wave)
> 10 hertz radio wave transmitter? Without giant components?
You need an antenna on the order of a wavelength to get any sort of
reasonable radiation efficiency. I.e. a 10 Hz transmitter needs a *BIG*
antenna! Like 30,000 km, or larger than the Earth's diameter.
> Anybody know what a nerophone (spelling?) is or how to build one?
Isn't this what you use to call an ancient roman emperor who likes
to play the fiddle?
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
r...@alanine.phri.nyu.edu -OR- {att,cmcl2,rutgers,hombre}!phri!roy
"Arcane? Did you say arcane? It wouldn't be Unix if it wasn't arcane!"
0000-John Winters(0000)
I know there are bettor solutions than a 30,000 kilometer antena at a full
wave. I am a ham. Anybody care to comment on a praticle design? I know
one exists. It has been used before. More an that part later.
new...@yoda.byu.edu
of the wave of the 10 Hz signal -- not true -- at one wave length, you get
zero transmission. (provided that the end of the antenna is open circuit.)
To get maximum efficiency, use an antenna 1/4 of the wavelength.
Now with wf=c you get w=c/f, and even 1/4 of that is huge. (w=wavelength,
f=frequency, and c=300,000,000 km/s) since you dont want something that
big, use some integer fraction of 1/4 and be willing to loose efficiency as you
shorten the antenna.
- Hal new...@yoda.byu.edu
Grenville Armitage
>In his response to <10 Hz ....> Roy Smith suggested an antenna the length
>of the wave of the 10 Hz signal -- not true -- at one wave length, you get
>zero transmission. (provided that the end of the antenna is open circuit.)
>To get maximum efficiency, use an antenna 1/4 of the wavelength.
..and all around the world antennas began to cease working.... :-)
gja
--
You're not drunk if you can lie on the floor
without holding on.
John Whitmore
>Anyone care to say how they would go about building an A0 (continuous wave)
>10 hertz radio wave transmitter? Without giant components?
>
was--literally--a generator. It is possible to modulate at 10 Hz (or
100 kHz, for that matter) by using a simple motor/generator
combination. Changing the generator exciter current modulates
the output amplitude.
At these low frequencies, however, it's not exactly radio.
Dominant energy transmission mechanisms would be soil conduction
or ionospheric conduction (the 60 kHz WWVB transmissions use the
ionospheric conduction channel, with a tethered baloon holding the
antenna, to keep time delay under control).
John Whitmore
Bob Myers
>f=frequency, and c=300,000,000 km/s) since you dont want something that
>big, use some integer fraction of 1/4 and be willing to loose efficiency as you
>shorten the antenna.
"Integer fraction?" Which particular integers did you have in mind? I'm
not willing to believe that an antenna will work if it simply happens to
be some fractional rational number multiple of the wavelength!
What everyone seems to be missing here is that extremely-low-frequency
communications systems usually are NOT radio; the coupling is purely
magnetic, and achieved via large coils. (This certainly impacts the
range, but the big advantage is that it works well below ground - most of the
time, we're taking about communications for spelunkers when talking about
communications using signals in the under 10 kHz range.) If I knew a bit
more about the particular application in question here, perhaps I could
comment further.
Bob Myers KC0EW HP Graphics Tech. Div.| Opinions expressed here are not
Ft. Collins, Colorado | those of my employer or any other
myers%hpf...@hplabs.hp.com | sentient life-form on this planet.
LEON PETER CONWAY
> Anyone care to say how they would go about building an A0 (continuous wave)
> 10 hertz radio wave transmitter? Without giant components?
>
the earth" to 1/4 of more than "the diameter of the earth."
This is probably ok, but don't the yanks run VLF transmitters for their
submarines ? The Omega antenna in Gippsland (?) is about 350m high (?)
Do they (as someone suggested) sacrifice transmission efficiency for
economical antenna size ?
lc
BACS Data Communications Group
In article <78...@pdn.paradyne.com>, win...@gumby.paradyne.com (John
Winters) writes:
> Anyone care to say how they would go about building an A0
> (continuous wave) 10 hertz radio wave transmitter? Without giant
> components?
There are signals of interest at 10 Hz and below. See _The Scientific
American_, March 1990: Geologists at Stanford University monitored an
increase in 0.1-Hz electrical activity 3 hours before the Loma Prieta,
California earthquake of October 1989. The article is vague about
receiving equipment but says that the antenna was "a metal cylinder
wrapped in wire."
Signals in the <10 Hz range also accompany magnetic storms. These can
be detected between widely-separated ground rods.
--
Frank Reid W9MKV re...@ucs.indiana.edu
Dave Post
John Whitmore writes:
> At these low frequencies, however, it's not exactly radio.
>Dominant energy transmission mechanisms would be soil conduction
>or ionospheric conduction (the 60 kHz WWVB transmissions use the
>ionospheric conduction channel, with a tethered baloon holding the
>antenna, to keep time delay under control).
About ten years ago WWVB radiated from just north of here ( Fort Collins,
Colorado ). In fact I made a 1 meter loop antenna that received a 60 mv RMS
signal from it. I have never seen any tethered balloons at the NBS site.
There is a curious, large horizontally oriented loop up on towers, though.
I know that WWV is still here, isn't WWVB?
David Post po...@hpfcla.hp.com hpfclabs!hpfcla!post
Steven L. Farmer
> Anyone care to say how they would go about building an A0 (continuous wave)
> 10 hertz radio wave transmitter? Without giant components?
>
I would think that a typical stero amp could be modified for response down to
10 Hz to kludge up a transmitter. That would leave you with the problem of
an antenna and possibly with problems with the FCC. Any conductor can be
an antenna - the problem is the extremely low values of radiation resistance
that have to be dealt with at these frequencies. Good is a very relative
term when it comes to antennas. For some applications, efficiencies on the
order of a tenth of a per cent might be very good. What in the world are
you planning to do with this thing anyway?
My memory is vague, but I recall a political flap years ago involving some-
thing called 'project sanguine'. It seems that the Navy planned to turn
a large portion of the state of Wis. into a giant vlf antenna. There were
predictions of thousands of volts being induced into things like barbed
wire fences leading to the electrocution of livestock and possibly people.
73's - Steve WA5RPF
John Reynolds
Am I the only other person who's interested in neurophones? If we're
talking about the same device, this was an interesting piece of gear
invented by someone in Texas in the 50's or early 60's. The idea was
that you modulate audio onto a 40KHz (or so) carrier and apply it to
electrodes attached to your head. The result is that you "hear" the
audio with no intermediate mechanical transducer. I haven't tried this,
but it seems like a neat concept. Does anybody out there have any further
information on this stuff? Is this the same device the original poster
was referring to??
John Reynolds
Tektronix TV Division
Beaverton, Oregon
Bob Myers
>10 Hz to kludge up a transmitter. That would leave you with the problem of
>an antenna and possibly with problems with the FCC. Any conductor can be
Actually, no problems with Uncle Charlie here; I don't recall the exact
frequency, but I do remember that the FCC's authority does not extend below
some particular (still fairly low from an RF viewpoint) frequency. I want
to say 10 kHz - anybody have a brain that isn't misfiring on 'em with a
better number? (Mine's exceptionally well-fried tonight!)
Dave Tiller N2KAU
--I would think that a typical stero amp could be modified for response down to
--10 Hz to kludge up a transmitter. That would leave you with the problem of
--an antenna and possibly with problems with the FCC. Any conductor can be
-
-Actually, no problems with Uncle Charlie here; I don't recall the exact
-frequency, but I do remember that the FCC's authority does not extend below
-some particular (still fairly low from an RF viewpoint) frequency. I want
-to say 10 kHz - anybody have a brain that isn't misfiring on 'em with a
-better number? (Mine's exceptionally well-fried tonight!)
-
-
According to my copy of Title 47, the FCC's authority begins at 9KHz.
It suggests, however, that you coordinate your activities with those
authorities that do regulate and/or use the RF spectrum below 9KHz.
Oddly enough it doesn't list any of them by name. Could it be secret?
It'd sure be interesting to hear about your trials and tribulations of
building a VLF transmitter.
--
David E. Tiller da...@tsdiag.ccur.com | Concurrent Computer Corp.
FAX: 201-870-5952 Ph: (201) 870-4119 (w) | 2 Crescent Place, M/S 117
UUCP: ucbvax!rutgers!petsd!tsdiag!davet | Oceanport NJ, 07757
ICBM: 40 16' 52" N 73 59' 00" W | N2KAU @ NN2Z
Paul Bame
"transmitter"? Filtering out the harmonics might be a problem at high power
and particularly at 20Hz - uh, how much power do you want and into what
load? Either a clean linear (inefficient) output stage so you don't make
"any" harmonics or else make sure the harmonics are in a range you don't
mind filtering. Like maybe build a power D-A converter (from power FETS?)
and drive it with a digital sine wave. Use enough samples (clock speed) and
resolution (bits) to make the frequency and amplitude of the
stairstep-generated harmonics something palatable (now where did I put that
FFT?).
Heck, you could use a homopolar generator :-)
-Paul "Spice is the Variety of Life"
pa...@hpldola.hp.com N0KCL
Dave Horsfall
new...@yoda.byu.edu writes:
| In his response to <10 Hz ....> Roy Smith suggested an antenna the length
| of the wave of the 10 Hz signal -- not true -- at one wave length, you get
| zero transmission. (provided that the end of the antenna is open circuit.)
| To get maximum efficiency, use an antenna 1/4 of the wavelength.
Hmmm... so I'd better cancel my plans for a full-wavelength 2m antenna, huh?
Someone better tell the ARRL as well...
--
Dave Horsfall (VK2KFU) Alcatel STC Australia da...@stcns3.stc.oz.AU
dave%stcns3.s...@uunet.UU.NET ...munnari!stcns3.stc.oz.AU!dave