RadioBanter

RadioBanter (https://www.radiobanter.com/)
-   Shortwave (https://www.radiobanter.com/shortwave/)
-   -   Minimum photons-per-second [amplitude] required for 150 KHz? (https://www.radiobanter.com/shortwave/120690-minimum-photons-per-second-%5Bamplitude%5D-required-150-khz.html)

Radium[_2_] June 18th 07 12:56 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
On Jun 17, 4:38 pm, "Mike Kaliski" wrote:

300,000
photons per second should do the trick, as that is the frequency of the
original signal and each photon can represent the amplitude of each half of
a single sine wave.


So the amount of photons-per-second should be double the frequency of
the carrier-wave? In my first post of the thread, I stated that the
carrier frequency for the AM signal is 150 KHz. Each photon in that
signal is 150 KHz. It's possible to have one 150 KHz photon, right?

My question was relating the modulator wave. If I have using 150 KHz
photons for my carrier-wave on AM radio, what is the minimum amount of
photons-per-second I would require to transmit, a modulator-signal
[through the 150 KHz carrier-signal] of 20 KHz? I am guessing 40,000
150-KHz-photons-per-seconds. Am I right?


Mike Kaliski June 18th 07 01:22 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 

"Radium" wrote in message
ups.com...
On Jun 17, 4:38 pm, "Mike Kaliski" wrote:

300,000
photons per second should do the trick, as that is the frequency of the
original signal and each photon can represent the amplitude of each half

of
a single sine wave.


So the amount of photons-per-second should be double the frequency of
the carrier-wave? In my first post of the thread, I stated that the
carrier frequency for the AM signal is 150 KHz. Each photon in that
signal is 150 KHz. It's possible to have one 150 KHz photon, right?

My question was relating the modulator wave. If I have using 150 KHz
photons for my carrier-wave on AM radio, what is the minimum amount of
photons-per-second I would require to transmit, a modulator-signal
[through the 150 KHz carrier-signal] of 20 KHz? I am guessing 40,000
150-KHz-photons-per-seconds. Am I right?


Radium

You can have a single photon oscillating at a frequency of 150,000 cycles
per second. Measuring that photon will give you a sample of 1/150,000th of a
second duration. If you want to do anything meaningful, you need to have a
whole lot more photons. If you modulate a 150kHz carrier with a signal of
20kHz then the bandwidth of the signal will extend from 150 kHz -20 kHz to
150 kHz +20 kHz or from 130-170 kHz. Signals centred on 150 kHz represent
just the carrier wave. Signals at 130 kHz and 170 kHz represent 100%
modulation of the carrier wave. Now the modulation of the carrier wave is
symmetrical about the center frequency, so you only need to measure one
half.

One way of recovering the signal is to measure the frequency of each photon
between 130 and 150 kHz at a rate of 300,000 samples per second. The
variation of each photon from the carrier frequency represents the
modulation. A 20 kHz signal can be accurately represented using 40,000
samples, but this is different from detecting modulation on a higher
frequency carrier wave.

Mike G0ULI



[email protected] June 18th 07 01:45 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
In rec.radio.amateur.antenna Radium wrote:
On Jun 17, 4:38 pm, "Mike Kaliski" wrote:


300,000
photons per second should do the trick, as that is the frequency of the
original signal and each photon can represent the amplitude of each half of
a single sine wave.


So the amount of photons-per-second should be double the frequency of
the carrier-wave? In my first post of the thread, I stated that the
carrier frequency for the AM signal is 150 KHz. Each photon in that
signal is 150 KHz. It's possible to have one 150 KHz photon, right?


My question was relating the modulator wave. If I have using 150 KHz
photons for my carrier-wave on AM radio, what is the minimum amount of
photons-per-second I would require to transmit, a modulator-signal
[through the 150 KHz carrier-signal] of 20 KHz? I am guessing 40,000
150-KHz-photons-per-seconds. Am I right?


No.

For AM with a 150 Khz carrier and a steady 20 Khz tone, you have to emit
1 130 Khz photon, 2 150 Khz photons, and 1 170 Khz photon approximately
every 12 microseconds.

--
Jim Pennino

Remove .spam.sux to reply.

Mike Kaliski June 18th 07 01:49 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 

wrote in message
...
In rec.radio.amateur.antenna Radium wrote:
On Jun 17, 4:38 pm, "Mike Kaliski" wrote:


300,000
photons per second should do the trick, as that is the frequency of

the
original signal and each photon can represent the amplitude of each

half of
a single sine wave.


So the amount of photons-per-second should be double the frequency of
the carrier-wave? In my first post of the thread, I stated that the
carrier frequency for the AM signal is 150 KHz. Each photon in that
signal is 150 KHz. It's possible to have one 150 KHz photon, right?


My question was relating the modulator wave. If I have using 150 KHz
photons for my carrier-wave on AM radio, what is the minimum amount of
photons-per-second I would require to transmit, a modulator-signal
[through the 150 KHz carrier-signal] of 20 KHz? I am guessing 40,000
150-KHz-photons-per-seconds. Am I right?


No.

For AM with a 150 Khz carrier and a steady 20 Khz tone, you have to emit
1 130 Khz photon, 2 150 Khz photons, and 1 170 Khz photon approximately
every 12 microseconds.

--
Jim Pennino

Remove .spam.sux to reply.


Nicely put Jim.

Mike G0ULI



Telamon June 18th 07 02:40 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
In article . com,
Radium wrote:

Snip

Go away cross posting nut case.

Plonk

--
Telamon
Ventura, California

Telamon June 18th 07 02:41 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
In article ,
"Mike Kaliski" wrote:

Snip

Plonk

--
Telamon
Ventura, California

Telamon June 18th 07 02:42 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
In article ,
wrote:

Snip

Plonk

--
Telamon
Ventura, California

John Smith I June 18th 07 02:48 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
Telamon wrote:
In article ,
"Mike Kaliski" wrote:


Ohh gawd, bizarre telemundo is back ...

PLONKERS!

JS

RHF June 18th 07 03:01 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
On Jun 17, 3:56 pm, "Dave" wrote:
"Radium" wrote in message

ups.com... Hi:

What is the minimum amount of photons-per-second needed for a 150 KHz
AM radio carrier wave to transmit audio signals? Around 20,000-photons-
per-second?


Thanks,


Radium


you should have stayed with the alt.sci or sci.physics groups, you don't
know what you are getting your self in for here!


as in 'go fish' ~ RHF

RHF June 18th 07 03:12 AM

Minimum photons-per-second [amplitude] required for 150 KHz?
 
On Jun 17, 4:45 pm, wrote:
In rec.radio.amateur.antenna Radium wrote:

On Jun 17, 4:05 pm, wrote:
So at any given time, you need some number of photons at different
frequencies to get the frequency components and some number of
photons at each frequency component to the the amplitude components
of the total signal.

Well, in FM the peak-to-peak amplitude remains constant but the energy
[frequency] varies.
In AM, the frequency remains constant but the peak to peak amplitude
varies.


You've never seen what an AM signal looks like on a spectrum analyzer,
have you?


Scroll down to "A More Realistic Spectrum"
- Go look at:http://www.fas.org/man/dod-101/navy/docs/es310/AM.htm
Check-out the two side-by-side Images


Hot flash for you, the AM modulation process creates other frequencies.

If you only have one frequency, you don't have modulation of any
kind.

--
Jim Pennino

Remove .spam.sux to reply.





All times are GMT +1. The time now is 08:52 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com