Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

I also don't think power lines would have any perceptible affect on a
40 Hz receiver. In USA, the electric power has a frequency of 60 Hz --
in Europe, its 50 Hz. Since 40 Hz is below these power frequencies, I
doubt they would cause interference on 40 Hz. If I was receiving at or
above the power frequencies, I do think there would be disturbance but
not if below.

Would any interferences from outer space be perceptible on a 40 Hz AM
receiver? Galactic noise?


Thanks,

Radium

He's baaaaaaaack.

In rec.radio.amateur.antenna Green Xenon [Radium] wrote:
Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

Most likely YOU would hear "Hab SoslI' Quch!" (your mother has a
smooth forehead!) as this is the command and control frequency for
Klingon Battle Cruisers.

--
Jim Pennino

Remove .spam.sux to reply.

Green Xenon [Radium] wrote:

...
Would any interferences from outer space be perceptible on a 40 Hz AM
receiver? Galactic noise?


Thanks,

Radium

Possibly "bleedover" from some guy next door operating his subwoofer(s),
60Hz equip., noise, etc. ...

Why not just run a big loop of wire about and hook it to the mic/aux.
input on some old high quality/low-audio-freq. capable stereo? You
could catch all the "bands" from 20Hz-40,000Hz! LOL

Regards,
JS

--
loudobbs.com -- you do have the power to be informed; but, first you
have to use it.

"Green Xenon [Radium]" wrote in message
...
Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

I also don't think power lines would have any perceptible affect on a
40 Hz receiver. In USA, the electric power has a frequency of 60 Hz --
in Europe, its 50 Hz. Since 40 Hz is below these power frequencies, I
doubt they would cause interference on 40 Hz. If I was receiving at or
above the power frequencies, I do think there would be disturbance but
not if below.

Would any interferences from outer space be perceptible on a 40 Hz AM
receiver? Galactic noise?


Thanks,

Radium

hey, its our favorite troll next to art back for more abuse... you should
really talk to art, he'll build you a 40hz antenna that you can aim like a
laser beam and see just what you can hear. why don't you ask the elf
researchers what they 'hear' at those frequencies.

On Sep 12, 4:22 pm, "Green Xenon [Radium]"
wrote:
Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

I also don't think power lines would have any perceptible affect on a
40 Hz receiver. In USA, the electric power has a frequency of 60 Hz --
in Europe, its 50 Hz. Since 40 Hz is below these power frequencies, I
doubt they would cause interference on 40 Hz. If I was receiving at or
above the power frequencies, I do think there would be disturbance but
not if below.

Would any interferences from outer space be perceptible on a 40 Hz AM
receiver? Galactic noise?

Thanks,

Radium

Heya ass-spelunker, I see you didn't take my advice to commit suicide
last year. But if you're gonna hang around here, I have to warn you
that a couple here got a real boner for you, especially Clowney. He
unveiled a secret to me -- told me that asspie's asses taste like
honey (hey, why do you think they call 'em "asspies.") Now, take my
advice and reject any advances these predators make on you. We don't
wanna turn you into a butt-hurt serial killer now. Avoid Clowney at
all costs -- notice how excited he is to have you back.

On Fri, 12 Sep 2008 15:22:43 -0700 (PDT), "Green Xenon [Radium]"
wrote:

What would be heard on a 40 Hz AM DX receiver

Very slow morse code. That's about the only form of AM modulation
that will work with such a low carrier frequency.

that uses the most
sensitive type of magnetic loop antenna?

I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

Well, if your carrier frequency is 40 Hz, the highest AM modulation
frequency that will work will be 20Hz. That's also approximately the
modulation bandwidth. There are a few young individuals that can hear
down to 10-30Hz, but most people can't. It's a form of hiss, but at a
much lower fequency.

I also don't think power lines would have any perceptible affect on a
40 Hz receiver. In USA, the electric power has a frequency of 60 Hz --
in Europe, its 50 Hz. Since 40 Hz is below these power frequencies, I
doubt they would cause interference on 40 Hz. If I was receiving at or
above the power frequencies, I do think there would be disturbance but
not if below.

Think again. It really depends on your receiver bandwidth. For AM,
it's going to have a fairly wide IF bandwidth in order to work at a
40Hz carrier. Although power line 60Hz will not be directly coupled
into the receiver, there's probably enough gain after the filter to
cause some problems. It's difficult to tell without clues about the
rx gain distribution and antenna configuration.

Would any interferences from outer space be perceptible on a 40 Hz AM
receiver? Galactic noise?

Not outer space. However, there is a substantial amount of
atomospheric noise at low frequencies, mostly from lightning and
atmospheric electricity discharges.
http://en.wikipedia.org/wiki/Atmospheric_noise
That's one reason why it's not useful to build an extremely sensitive
VLF receiver. Whatever you're trying to hear, it literally buried in
atmospheric noise.

Thanks,
Radium

Give up.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Green Xenon [Radium] wrote:
Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

Not strictly true I think - depends on the modulation scheme - how else
do you think we manage to get 56K bps down a 3KHz phone line.

Cheers

IAn

"Ian Thompson-Bell" wrote in message
...
Green Xenon [Radium] wrote:
Hi:

What would be heard on a 40 Hz AM DX receiver that uses the most
sensitive type of magnetic loop antenna? I doubt there would be any
hissing since that artifact would involve high-frequency sounds and a
40 Hz carrier cannot transport modulation-signals higher than 40 Hz
[violation of Nyquist theorem].

Not strictly true I think - depends on the modulation scheme - how else do
you think we manage to get 56K bps down a 3KHz phone line.

Cheers

IAn

if you really want to have fun try plugging in a 40hz carrier with a 100hz
modulation and do the sum and difference frequencies to find the
sidebands... how do you explain negative frequencies?? are they going back
in time? taking information to before it was sent? or do they appear
before the signal starts?

Dave wrote:
how do you explain negative frequencies??


are they going back in time?
No.

taking information to before it was sent?
No.

or do they appear before the signal starts?
No.


A phase inversion is all there is to it.