@uniqueandprosperous I don't have any idea where you could find one or who would build one. 72hz is a very low frequency, and I think the only thing that uses a frequency that low is submarines.
@uniqueandprosperous Yep. You would have to find or a build a transmitter for that low frequency. The coils for such a low frequency would have a lot of turns.
Forgive me for asking so many questions & thank u for answering but.. what I am trying to learn how to do is send little beeps to a crystal radio set .. but the beeps are too fast to tap out & too slow to sound like music ..would I still need an oscillator..or is there a simpler & cheaper way to send?
@uniqueandprosperous The easiest thing to do is find a small AM transmitter. There are several types for sale on the internet. Then feed the beeps into the audio jack on the transmitter.
@uniqueandprosperous If you have a crystal set that will tune shortwave, it would definitely pick up the signal 30 ft away. You wouldn't hear much though because you would need a beat frequency oscillator to beat against the signal and produce a tone.
I do have another video called spark gap transmitter, but there are no tubes in it.
thank u.. your explaination was so much easier to understand than what I've been reading ... can u tell me how to set up carbon microphone in series w/ground..are those the plates they used to bury in the ground sort of ground battery? did they not bury them in the ground under old telegraph poles?
@uniqueandprosperous The mic would be inbetween the transmitter and a ground rod although this is not good way to modulate a transmitter, and the risk of RF burns are high. This style of transmitter is really only good for morse code transmission. Whatever method is used to transmit voice will cause the frequency to swing.
I have no idea about the plates under telegraph poles.
@uniqueandprosperous The tube in the power supply rectifies the AC current into DC current, and the other tube oscillates to create the radio signal. The front coil is part of a tuned circuit with a capacitor that is tuned to the frequency the operator wants to transmit on. The rear coil is what couples the signal into the antenna.
@amermtrs If you played the music loud enough next to the transmitter the vibrations from the speaker would probably vibrate the coil enough to transmit something, although it would probably not be recognizable. I've seen crude setups where a carbon microphone was connected in series with the ground to transmit voice. There are also other ways to do this such as heising and plate modulation.
@N2RRAny It would be hard to get on frequency on 20 meters, and the chirp would probably be terrible. With some tinkering it would probably do OK on 20, but a regulated power supply would help it a lot.
do u know where I might find one or who might build one for me ? J
uniqueandprosperous 3 weeks ago
@uniqueandprosperous I don't have any idea where you could find one or who would build one. 72hz is a very low frequency, and I think the only thing that uses a frequency that low is submarines.
amermtrs 3 weeks ago
sorry more questions .. is there a way to transmit morse on a very low 72hz or 144hz band for only a few ft.
uniqueandprosperous 3 weeks ago
@uniqueandprosperous Yep. You would have to find or a build a transmitter for that low frequency. The coils for such a low frequency would have a lot of turns.
amermtrs 3 weeks ago
Nice homebrew QRP! and as a bonus, you could use it as a theremin! RW
Radiowild 1 month ago
@Radiowild Haha. I hadn't thought of that, but that would work. It would be the first theremin performance on 80 meters.
amermtrs 1 month ago
Forgive me for asking so many questions & thank u for answering but.. what I am trying to learn how to do is send little beeps to a crystal radio set .. but the beeps are too fast to tap out & too slow to sound like music ..would I still need an oscillator..or is there a simpler & cheaper way to send?
uniqueandprosperous 1 month ago
@uniqueandprosperous The easiest thing to do is find a small AM transmitter. There are several types for sale on the internet. Then feed the beeps into the audio jack on the transmitter.
amermtrs 1 month ago
didn't u have a 2nd video where u showed a spark gap in front of the tube .. I can't seem to find it again....thank u
uniqueandprosperous 1 month ago
@uniqueandprosperous If you have a crystal set that will tune shortwave, it would definitely pick up the signal 30 ft away. You wouldn't hear much though because you would need a beat frequency oscillator to beat against the signal and produce a tone.
I do have another video called spark gap transmitter, but there are no tubes in it.
amermtrs 1 month ago
is there a way to transmit just a few feet away(under 30 feet) to an old crystal radio set or a foxhole radio? w/this type of transmitter ?
uniqueandprosperous 1 month ago
thank u.. your explaination was so much easier to understand than what I've been reading ... can u tell me how to set up carbon microphone in series w/ground..are those the plates they used to bury in the ground sort of ground battery? did they not bury them in the ground under old telegraph poles?
uniqueandprosperous 1 month ago
@uniqueandprosperous The mic would be inbetween the transmitter and a ground rod although this is not good way to modulate a transmitter, and the risk of RF burns are high. This style of transmitter is really only good for morse code transmission. Whatever method is used to transmit voice will cause the frequency to swing.
I have no idea about the plates under telegraph poles.
amermtrs 1 month ago
sorry that was could u put music NEXT to the set where u moved your hand over it & would it play that music or send it ?
uniqueandprosperous 1 month ago
@uniqueandprosperous The tube in the power supply rectifies the AC current into DC current, and the other tube oscillates to create the radio signal. The front coil is part of a tuned circuit with a capacitor that is tuned to the frequency the operator wants to transmit on. The rear coil is what couples the signal into the antenna.
amermtrs 1 month ago
@amermtrs If you played the music loud enough next to the transmitter the vibrations from the speaker would probably vibrate the coil enough to transmit something, although it would probably not be recognizable. I've seen crude setups where a carbon microphone was connected in series with the ground to transmit voice. There are also other ways to do this such as heising and plate modulation.
amermtrs 1 month ago
I'm just learning ..can u tell me what the tubes where for, why you have 2 coils & could u put music nest to it and would it broadcast it?
uniqueandprosperous 1 month ago
Very nice!PP2WHB
ballest013 1 month ago
@ballest013 Thanks!
amermtrs 1 month ago
i always wanted to build a ham radio, like in the 30s but those kids were smarter than me.
eli5771 1 month ago in playlist More videos from amermtrs
@eli5771 Its not too hard to build one. Finding the old style pieces is the hardest part.
amermtrs 1 month ago
Ah! Got it. Tnx!
N2RRAny 2 months ago
Love the way you keep everything true to period and authenticity. What do you mean "if your brave enough" to change band operation?
N2RRAny 2 months ago
@N2RRAny It would be hard to get on frequency on 20 meters, and the chirp would probably be terrible. With some tinkering it would probably do OK on 20, but a regulated power supply would help it a lot.
amermtrs 2 months ago