Home |
Search |
Today's Posts |
|
#2
![]() |
|||
|
|||
![]()
No but the radio is very similar
I think I would almost prefer a rocket radio for my son if they are still available! They look way cool! cheers Peter wrote in message oups.com... Was the radio shaped like a "rocket"? Like: http://www.tompolk.com/radios/rocket.html or: http://home.earthlink.net/~wb5rex/xt...osrockets.html There is a company making a reproduction. I will dig out their name and URL tonight. Terry |
#3
![]() |
|||
|
|||
![]()
The modern reproduciton that I have was made by DaMart Company.
I found this web site in Engalnd: http://www.greatgizmos.co.uk/damert_company_page_1.htm Rocket Radio (Reference #D4025) It receives radio signals without using batteries! In the late 1950's, kids learnt that the magic of radio could be achieved without batteries through an ingenious gizmo known as the Rocket Radio. Now it's back! By attaching the antenna/ground wire and tuning the nose cone, a handful of AM stations can be received and heard through a crystal earphone. An informative booklet will help curious minds understand the science behind radio transmissions and crystal diodes. For ages 8 and up. The show a blue one, but mine is red. My sister tore mine up back in 1960. She bought me one in 2001 for my 50th birthday. My orignal was blue but I didn't complain. It works pretty well, but I found a site that has some improvements, but I can't find the $#%^ URL right now. I never got around to making them, after all why complicate something simple that really works. When I find the URL I will post it here as a new post. Terry Terry : |
#4
![]() |
|||
|
|||
![]()
"peter berrett" wrote in message
... No but the radio is very similar I think I would almost prefer a rocket radio for my son if they are still available! They look way cool! cheers Peter http://cgi.ebay.com/ws/eBayISAPI.dll...482786 4&rd=1 |
#5
![]() |
|||
|
|||
![]()
peter berrett wrote:
Does anyone know who manufactured these sets and whether they are still available to be purchased? many pages out there. A Google search for crystal radio sets turned up many sites. Some of them are below: http://www.clarion.org.au/crystalset/ http://www.thebest.net/wuggy/ http://www.midnightscience.com/ http://www.midnightscience.com/kits.html http://journeytoforever.org/edu_radio.html http://www.schmarder.com/radios/crystal/ http://www.electronics-tutorials.com...-radio-set.htm http://www.streettech.com/archives_DIY/crystalSet.html http://store.yahoo.com/mbaciu/rocrad19512.html http://www.bluesky.com/warren/radios/rocketradio/ mike |
#6
![]() |
|||
|
|||
![]()
I think you'd be better off getting one commercially first. Then experiment
with it so you can make your own. It's much less frustrating that way. Purists insist on using a chunk of galena and a "cat's whisker" for the detector, but you can substitute a plain old 1N34 germanium diode to accomplish the same thing without all that trouble of having to poke around to find a "hot spot" on the chunk of galena. There are different ways to accomplish tuning. You can have a variable coil, or a variable capacitor. Big variable caps can still be found, though not new, and they're easier to work with. Smaller variable caps can be salvaged from junked transistor radios. It's been said that "A dollar in the antenna is worth ten in the receiver." That holds true. String up as much long wire as you can for your antenna. And also make sure you have a good earth ground. That will really help. After you get all this done, please let us know what you hear!!!! Matt J. McCullar, KJ5BA Arlington, TX |
#7
![]() |
|||
|
|||
![]()
Matt J. McCullar wrote:
Purists insist on using a chunk of galena and a "cat's whisker" for the detector, but you can substitute a plain old 1N34 germanium diode to accomplish the same thing without all that trouble of having to poke around to find a "hot spot" on the chunk of galena. In a homebrew crystal radio, I tried a chunk of galena, but it did not work as well as an iron pyrite ("fool's gold") crystal. For a "cat's whisker", I used a small gold-plated safety pin. In my experience, the old high-impedence headphones (which typically have Bakelite ear pieces and a headband made of spring steel covered with cloth or leather) work much better than the cheap in-the-ear kind found on modern crystal radio kits. As mentioned earlier, http://www.midnightscience.com has some great crystal radio info. --Leigh Marrin/KM6JE in Santa Barbara, Calif. |
#8
![]() |
|||
|
|||
![]()
http://www.crystalradio.net/misc/rocket/index.shtml
Good Luck! Mike KC6SEG "peter berrett" wrote in message u... Hi all Cam someone please help me with a query I have about an old crystal set I used to own. When I first came to live in Melbourne (1970s) my parents purchased for me a small crystal set.at a local, now long gone, toy store. As I recall the set was manufactured in England although I may be wrong on this point. It was housed in a small plastic box (red?) and from memory was about 2 inches long and maybe an inch wide and high. Inside the box was a small wound coil (about 1/4" diameter) around a thin cardboard tube. There was a ferrite rod inside this which could be slid back and forth within the tube by means of a small rod that stuck out of the end of the ferte rod and protruded from the end of the box. This was used for tuning stations. There was also a piece of wire coming from the box with an alligator clip on the end. This was the antenna and by attaching it to a long piece of wire one could receive stations. There was also another piece of twin wire protruduing from the box which went to a crystal earpiece so that you could listen to stations. Aside from this I think there were only two other components - a diode and a capacitor as I recall which formed the crystal set circuit. Unfortunately the set is now lost after so many years. This was my first introduction to radio and despite moving on to bigger radios and getting my ham license, this example of a crystal set has always stuck in my mind as being a particularly simple but efficient example of electrical engineering. I now have a young son of my own and would like very much to buy one of these sets. Does anyone know who manufactured these sets and whether they are still available to be purchased? cheers Peter VK3PB |
#9
![]() |
|||
|
|||
![]() Thanks to everyone who replied to my query about Crystal Sets. I have firm plans to purchase a rocket radio for my son. I have built my own crystal sets in the past but I think for a present the rocket radio is hard to beat. That aside I have another query for which I would be grateful if people could provide a response. When I used to build crystal radios I found that my voltmeter would show a small voltage when measuring the output of the circuit. For some time I have toyed with the idea of building a crystal set transmitter which seems to me to be a logical extension of the idea of a crystal set reciever. First one would tap a large coil in parrallel with a variable capacitor and attached to a long wire. Several taps would extract the strongest stations in the vicinity. Each signal extracted would then be rectified by the use of 4 diodes so that a pulsating DC current is generated. Finally the various DC currents would be combined and smoothed out to provide a power souce for the transmitter stage. Next, a simple single transistor crystal locked transmitter would be built which would be powered by the dc current mentioned earlier. This could be keyed on and off to give a morse signal. Finally, and separately, a short wave crystal radio could be built for reception on the frequency of the transmitter stage Is such a project doable or is the power that you would extract out of the air too low to drive transistors etc? cheers peter "peter berrett" wrote in message u... Hi all Cam someone please help me with a query I have about an old crystal set I used to own. When I first came to live in Melbourne (1970s) my parents purchased for me a small crystal set.at a local, now long gone, toy store. As I recall the set was manufactured in England although I may be wrong on this point. It was housed in a small plastic box (red?) and from memory was about 2 inches long and maybe an inch wide and high. Inside the box was a small wound coil (about 1/4" diameter) around a thin cardboard tube. There was a ferrite rod inside this which could be slid back and forth within the tube by means of a small rod that stuck out of the end of the ferte rod and protruded from the end of the box. This was used for tuning stations. There was also a piece of wire coming from the box with an alligator clip on the end. This was the antenna and by attaching it to a long piece of wire one could receive stations. There was also another piece of twin wire protruduing from the box which went to a crystal earpiece so that you could listen to stations. Aside from this I think there were only two other components - a diode and a capacitor as I recall which formed the crystal set circuit. Unfortunately the set is now lost after so many years. This was my first introduction to radio and despite moving on to bigger radios and getting my ham license, this example of a crystal set has always stuck in my mind as being a particularly simple but efficient example of electrical engineering. I now have a young son of my own and would like very much to buy one of these sets. Does anyone know who manufactured these sets and whether they are still available to be purchased? cheers Peter VK3PB |
#10
![]() |
|||
|
|||
![]()
The old Raytheon ``What to do with your CK722'' project book has
a crystal-set-powered transistor radio, taking the DC from a crystal set output and using it to power a CK722 amplifier. They used the same station for both, however, which was a major conceptual error. You want to use a local for the power, to amplify a more distant station. -- Ron Hardin On the internet, nobody knows you're a jerk. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Drake TR-3 transceiver synthesizer upgrade | Homebrew | |||
Drake TR-3 transceiver synthesizer upgrade | Homebrew | |||
Crystal Oven Pinout | Homebrew | |||
Crystal Oven Pinout | Homebrew | |||
Please help id crystal holders | Boatanchors |