Ah, the memories… I was 8 years of age when I first started making my own crystal sets. All to listen to 3XY and/or the test cricket. Thus began my life-long interest in radio and radio wave propagation. Nice one Peter!
About 58 years ago while on holiday in Florida, I obtained some rock samples that were glued to a sheet of cardboard. One of them was quartz. So later on I ripped it off the cardboard and used it as the detector in my made crystal radio. It worked perfectly.
Talk about bring back memories. I was 14 or 15 at the time. My very first crystal radio was made with a galena. It was a small, round hunk of rock. Used a pin as the detector and could receive the stronger San Francisco radio stations. I used a very long wire, it ran from my bedroom up to the top of the hill next to us (our property line was near the top). Your headphones look like what I remember mine being at the time. Thanks for the trip back in time Peter.
FB Peter: I have often thought that a rite of passage for radio amateurs should be poking a chunk of Galena as you did. I built a receiver like this in London many years ago (it is on the SolderSmoke blog). I went on to try it with Fools Gold (Iron Pyrite) that Mike KL7R (SK) had sent me from Alaska. It also worked fine (once you found the sweet spot!) 73 Bill N2CQR
Dear Peter as your usual, you have done a very interesting experiment, one of the milestones of the radio electronics. Well done! Go straight in this way! Greetings from Rome. Giovanni I0KQB
The most sensitive spots on the surface of galena are at the sites of crystalline faults, e.g. edges and steps in the surface. Seek these out and avoid large, flat shiny areas which are usually rather poor. Some crystal set builders favour a variety colloquially called "steel galena" where the surface crystallises very rough rather than shiny, as this is often the best material for this purpose. Scruffy looking crystals often work better than the nice, shiny cubes - leave the latter for the collectors. And don't forget to remove the galena after each session and keep it in your trouser pocket in order for it to cure all your ailments... 😉
Peter, have you ever discussed the reason for a 60 cycle hum when we're fiddling with the whisker or generally reconnecting wires in a crustal set? I imagine it has something to do with microvolts on a ground that is on or near a domestic ground or bonding. I wonder if it can be 'harvested' (albeit smoothed and rectified) to add bias to a diode, say a silicon diode. I read somewhere that in the early days with few broadcast stations, set makers actually used the signal from a stronger (usually nearer) source to add bias and assist the reception of a weaker signal. Something I'd love to see experimented-with. Something else is doubling the diode (or as you say, two whiskers) to perhaps add microamps of signal, and finding how this changes the necessary impedance matching. Something still further is whether a set of 4 diodes in abridge (or 8 if doubled) can give a full-envelope detection and possibly better sound quality?
I found that a lower resistor across the crystal earphone worked better. I was using a 1N5711 diode and not a crystal when I did it. I found that 2K was best in my setup.
I used to sit with my dad making these 60 years ago. Great memories ......just a thought....could you not smooth down the top and bottom surfaces of the Galena, just to give you some flat spots so you can make better contact
Ah, the memories… I was 8 years of age when I first started making my own crystal sets. All to listen to 3XY and/or the test cricket.
Thus began my life-long interest in radio and radio wave propagation. Nice one Peter!
About 58 years ago while on holiday in Florida, I obtained some rock samples that were glued to a sheet of cardboard. One of them was quartz. So later on I ripped it off the cardboard and used it as the detector in my made crystal radio. It worked perfectly.
Talk about bring back memories. I was 14 or 15 at the time. My very first crystal radio was made with a galena. It was a small, round hunk of rock. Used a pin as the detector and could receive the stronger San Francisco radio stations. I used a very long wire, it ran from my bedroom up to the top of the hill next to us (our property line was near the top). Your headphones look like what I remember mine being at the time. Thanks for the trip back in time Peter.
FB Peter: I have often thought that a rite of passage for radio amateurs should be poking a chunk of Galena as you did. I built a receiver like this in London many years ago (it is on the SolderSmoke blog). I went on to try it with Fools Gold (Iron Pyrite) that Mike KL7R (SK) had sent me from Alaska. It also worked fine (once you found the sweet spot!) 73 Bill N2CQR
Great demonstration, Peter. Very interesting way of building a simple crystal radio.
Dear Peter
as your usual, you have done a very interesting experiment, one of the milestones of the radio electronics. Well done!
Go straight in this way!
Greetings from Rome.
Giovanni I0KQB
So instructive 👏 good job 👍
The most sensitive spots on the surface of galena are at the sites of crystalline faults, e.g. edges and steps in the surface. Seek these out and avoid large, flat shiny areas which are usually rather poor. Some crystal set builders favour a variety colloquially called "steel galena" where the surface crystallises very rough rather than shiny, as this is often the best material for this purpose. Scruffy looking crystals often work better than the nice, shiny cubes - leave the latter for the collectors. And don't forget to remove the galena after each session and keep it in your trouser pocket in order for it to cure all your ailments... 😉
Peter, have you ever discussed the reason for a 60 cycle hum when we're fiddling with the whisker or generally reconnecting wires in a crustal set? I imagine it has something to do with microvolts on a ground that is on or near a domestic ground or bonding. I wonder if it can be 'harvested' (albeit smoothed and rectified) to add bias to a diode, say a silicon diode. I read somewhere that in the early days with few broadcast stations, set makers actually used the signal from a stronger (usually nearer) source to add bias and assist the reception of a weaker signal. Something I'd love to see experimented-with. Something else is doubling the diode (or as you say, two whiskers) to perhaps add microamps of signal, and finding how this changes the necessary impedance matching. Something still further is whether a set of 4 diodes in abridge (or 8 if doubled) can give a full-envelope detection and possibly better sound quality?
Great video Peter.
Please show us twin whisker setup. Thank you.
I found that a lower resistor across the crystal earphone worked better. I was using a 1N5711 diode and not a crystal when I did it.
I found that 2K was best in my setup.
I used to sit with my dad making these 60 years ago. Great memories ......just a thought....could you not smooth down the top and bottom surfaces of the Galena, just to give you some flat spots so you can make better contact
I have a chunk of galena. I will give this a try.
That is impressive. Must try some.
I guess didn't get from Jaycar.
Oldschool!
Hello from South Wales. I like your style sir. I plan on buying your books, which one is best to buy first?
Thanks. Depends on what topic you're most interested in. I'd suggest Minimum QRP.
Good result :)
Better build these before more a.m. stations begin to shut down 😢
Very good! A question:Do you think quartz instead of galena is equally good?Thank you
I can't say anything about quartz as I haven't tried it. Galena is definitely more sensitive but more critical compared to pyrite.
@@vk3ye What do you mean about "more critical compared to pyrite"?
@@ebonyivory149 Harder to find a good spot to get reception. See the video for a demonstration.
It's amazing what will work. I tried a range of junk and by far the best was a Metallised scrap of plastic.
en.wikipedia.org/wiki/Metallised_film.
I did it with Pencil tip vs razor blade, free of cost.
Great demo, if only there was something worth listening to down on AM broadcast :)
774 AM Melbourne has lots of interesting content.
ABC Radio National has a lot of decent random programs. I think they're still kicking it on AM.
Agreed, nothing worth listening to on commercial radio. Though swifties will disagree I'm sure.
Great video Peter.
Please show us twin whisker set-up please.😊
A small local station can be good as a source of local news.