So crystal sets, they used the signal to power the head set, yeah.
I wonder if a simplistic mobile phone could use the signal to power basic operation?
I’m guessing modern mobile phone signals would be more powerful than old wireless signals.
Peak Warming Man said:
So crystal sets, they used the signal to power the head set, yeah.
I wonder if a simplistic mobile phone could use the signal to power basic operation?
I’m guessing modern mobile phone signals would be more powerful than old wireless signals.
you could only listen.
JudgeMental said:
Peak Warming Man said:
So crystal sets, they used the signal to power the head set, yeah.
I wonder if a simplistic mobile phone could use the signal to power basic operation?
I’m guessing modern mobile phone signals would be more powerful than old wireless signals.
you could only listen.
Wiki bit on the power available, basically SFA.
As a crystal radio has no power supply, the sound power produced by the earphone comes solely from the transmitter of the radio station being received, via the radio waves captured by the antenna. The power available to a receiving antenna decreases with the square of its distance from the radio transmitter. Even for a powerful commercial broadcasting station, if it is more than a few miles from the receiver the power received by the antenna is very small, typically measured in microwatts or nanowatts. In modern crystal sets, signals as weak as 50 picowatts at the antenna can be heard. Crystal radios can receive such weak signals without using amplification only due to the great sensitivity of human hearing, which can detect sounds with an intensity of only 10−16 W/cm2. Therefore, crystal receivers have to be designed to convert the energy from the radio waves into sound waves as efficiently as possible. Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.
JudgeMental said:
JudgeMental said:
Peak Warming Man said:
So crystal sets, they used the signal to power the head set, yeah.
I wonder if a simplistic mobile phone could use the signal to power basic operation?
I’m guessing modern mobile phone signals would be more powerful than old wireless signals.
you could only listen.
Wiki bit on the power available, basically SFA.
As a crystal radio has no power supply, the sound power produced by the earphone comes solely from the transmitter of the radio station being received, via the radio waves captured by the antenna. The power available to a receiving antenna decreases with the square of its distance from the radio transmitter. Even for a powerful commercial broadcasting station, if it is more than a few miles from the receiver the power received by the antenna is very small, typically measured in microwatts or nanowatts. In modern crystal sets, signals as weak as 50 picowatts at the antenna can be heard. Crystal radios can receive such weak signals without using amplification only due to the great sensitivity of human hearing, which can detect sounds with an intensity of only 10−16 W/cm2. Therefore, crystal receivers have to be designed to convert the energy from the radio waves into sound waves as efficiently as possible. Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.
Jolly good, so how can we make money out of it then?
Peak Warming Man said:
JudgeMental said:
JudgeMental said:you could only listen.
Wiki bit on the power available, basically SFA.
As a crystal radio has no power supply, the sound power produced by the earphone comes solely from the transmitter of the radio station being received, via the radio waves captured by the antenna. The power available to a receiving antenna decreases with the square of its distance from the radio transmitter. Even for a powerful commercial broadcasting station, if it is more than a few miles from the receiver the power received by the antenna is very small, typically measured in microwatts or nanowatts. In modern crystal sets, signals as weak as 50 picowatts at the antenna can be heard. Crystal radios can receive such weak signals without using amplification only due to the great sensitivity of human hearing, which can detect sounds with an intensity of only 10−16 W/cm2. Therefore, crystal receivers have to be designed to convert the energy from the radio waves into sound waves as efficiently as possible. Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.
Jolly good, so how can we make money out of it then?
Use alternative medicine crystals and tell people you can pick up the Woodstock festival with them
Peak Warming Man said:
JudgeMental said:
JudgeMental said:you could only listen.
Wiki bit on the power available, basically SFA.
As a crystal radio has no power supply, the sound power produced by the earphone comes solely from the transmitter of the radio station being received, via the radio waves captured by the antenna. The power available to a receiving antenna decreases with the square of its distance from the radio transmitter. Even for a powerful commercial broadcasting station, if it is more than a few miles from the receiver the power received by the antenna is very small, typically measured in microwatts or nanowatts. In modern crystal sets, signals as weak as 50 picowatts at the antenna can be heard. Crystal radios can receive such weak signals without using amplification only due to the great sensitivity of human hearing, which can detect sounds with an intensity of only 10−16 W/cm2. Therefore, crystal receivers have to be designed to convert the energy from the radio waves into sound waves as efficiently as possible. Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.
Jolly good, so how can we make money out of it then?
Lie about the drawbacks. get a good advertising agency. lie.
From what I have read of crystal sets the only problem with them is you can only get reception at night whilst hiding in bed under your blankets.
JudgeMental said:
Peak Warming Man said:
JudgeMental said:Wiki bit on the power available, basically SFA.
As a crystal radio has no power supply, the sound power produced by the earphone comes solely from the transmitter of the radio station being received, via the radio waves captured by the antenna. The power available to a receiving antenna decreases with the square of its distance from the radio transmitter. Even for a powerful commercial broadcasting station, if it is more than a few miles from the receiver the power received by the antenna is very small, typically measured in microwatts or nanowatts. In modern crystal sets, signals as weak as 50 picowatts at the antenna can be heard. Crystal radios can receive such weak signals without using amplification only due to the great sensitivity of human hearing, which can detect sounds with an intensity of only 10−16 W/cm2. Therefore, crystal receivers have to be designed to convert the energy from the radio waves into sound waves as efficiently as possible. Even so, they are usually only able to receive stations within distances of about 25 miles for AM broadcast stations, although the radiotelegraphy signals used during the wireless telegraphy era could be received at hundreds of miles, and crystal receivers were even used for transoceanic communication during that period.
Jolly good, so how can we make money out of it then?
Lie about the drawbacks. get a good advertising agency. lie.
Get Gwyneth Paltrow to sell them and say if you put them up your lady bits you can communicate with your inner self
powerful man made radio signals have been around going way back, to spark gap transmitters perhaps, or whatever were called, they sort of worked similar to the ignition circuit in an old Holden, like the points closed, charged the primary winding and core, then the points opened and the field collapsed very fast inducing a high voltage in the secondary, which rang, or oscillated as energy decayed.
Add some tuning to that idea, a tank circuit (you can mess with that idea and go up multiples of the frequency too), make it half stable so it didn’t frequency drift too much with temp etc. There were high frequency mechanical generators too, way back.
modern radio RX works well down approaching the background noise floor, or into the noise floor CDMA/spread spectrum does, as recall, by way of some magic, which escapes me presently. Down in the uV (microVolts) range, fractions of, on the antenna, and there’s things called transistors, and at higher frequencies the noise these make while amplifying that tiny radio signal matters, they’re better if they don’t contribute too much (above) the noise floor. There’s also in all that, to make it work, something called impedance matching, which for you and me is the equivalent of choosing the right gear to go up a hill in the old Holden, but in electronics it’s coils and capacitors.
back in the day, way back, you could make an RF transmitter that was marginally more controlled than lightning, there was no television signals to wipe out or interfere with, there was no radio inspector. Anything that traversed the aether was cool, just a crackle was cool.
Am reading about the origins of the “baby wireless” developed by a chap from Melbourne for use with the flying doctor service. It was a crystal set and could receive radio all right. But getting it to transmit was very much more difficult, and the best that could be done on battery power was Morse code using a spark generator.
Even that was exceedingly difficult, the previous prototype even had difficulty transmitting using the power using a belt drive off a motor car engine.
back in the day, way back, you could make an RF transmitter that was marginally more controlled than lightning, there was no television signals to wipe out or interfere with, there was no radio inspector. Anything that traversed the aether was cool, just a crackle was cool
I assume if the radio inspector was travelling around looking for radio signals you’d eat the radio as to not get in trouble