Sign up to save your podcasts
Or
Share HPR4291: AM on the Nyquist Prompt
Share to email
Share to Facebook
Share to X
Share to email
Share to Facebook
Share to X
Or
HPR4291: AM on the Nyquist Prompt
This show has been flagged as Clean by the host.
Studying for a license from the Radio Society of Great Britain lead to
an interesting experiment.
What happens if one sine wave is modulated with another sine wave?
Similar to sending a pure tone over AM radio.
Apparently the result is two frequencies, one equal to the difference
of the two original frequencies and one equal to the sum.
Creating two tones and multiplying them in Nyquist Prompt in Audacity
then plotting the resulting spectrum concurs.
(mult (sound (hzosc 1000)) (sound (hzosc 500)))
The original tones were 1 kHz and 0.5 kHz.
The result was a peak at 0.5 kHz (the difference) and one at 1.5 kHz
(the sum).
On another note, the manual mentions in practice if one of the tones
is the carrier frequency and one of them is the signal, then the carrier
should not be modulated all the way down to zero or all the way up to
maximum. This avoids distortion and clipping so the quality is better
when received. It is also more power efficient so the transmission can
travel further given the transmitter has a limited power output.
Provide feedback on this episode.
View all episodes
By Hacker Public Radio
4.2
3434 ratings
This show has been flagged as Clean by the host.
Studying for a license from the Radio Society of Great Britain lead to
an interesting experiment.
What happens if one sine wave is modulated with another sine wave?
Similar to sending a pure tone over AM radio.
Apparently the result is two frequencies, one equal to the difference
of the two original frequencies and one equal to the sum.
Creating two tones and multiplying them in Nyquist Prompt in Audacity
then plotting the resulting spectrum concurs.
(mult (sound (hzosc 1000)) (sound (hzosc 500)))
The original tones were 1 kHz and 0.5 kHz.
The result was a peak at 0.5 kHz (the difference) and one at 1.5 kHz
(the sum).
On another note, the manual mentions in practice if one of the tones
is the carrier frequency and one of them is the signal, then the carrier
should not be modulated all the way down to zero or all the way up to
maximum. This avoids distortion and clipping so the quality is better
when received. It is also more power efficient so the transmission can
travel further given the transmitter has a limited power output.
Provide feedback on this episode.
More shows like Hacker Public Radio
View all
Security Now (Audio)
1,971 Listeners
Off The Hook
117 Listeners
No Agenda Show
5,938 Listeners
The Changelog: Software Development, Open Source
283 Listeners
LINUX Unplugged
265 Listeners
BSD Now
89 Listeners
Open Source Security
43 Listeners
Late Night Linux
154 Listeners
The Linux Cast
35 Listeners
Darknet Diaries
7,864 Listeners
This Week in Linux
36 Listeners
Linux Dev Time
21 Listeners
Hacking Humans
314 Listeners
2.5 Admins
92 Listeners
Linux Matters
20 Listeners