From: glitwin@craysea.cray.com (Gary Litwin)

A few weeks ago, I posted a request for any info leading to a Crystal Rocket
Radio like I had as a kid in the 50's.

I jogged a lot of pleasant memories for a lot of net readers, but I still
haven't found one of my own.

SOOOOO, I decided to make one, and here are the plans etc, for how I did it.

There are many MANY circuits for ccrystal radios, but I selected one that has
only a loopstick, diode and earphone, to remain faithful to the design of the
one I had as a kid.

I have built a couple of these now, and they DO work! (About as good as the
original).

Please send any feedback, suggestions for improvements, true-life stories
about how you built one, etc, to :

glitwin@craysea.cray.com

Thanks to all who responded to my original post, and those who forwarded it
to other lists and newsgroups. I received more than 40 (!) responses!

Without further ado:


          Pictorial/schematic for Crystal Rocket radio


   ANT	O-----+-------------->[--------------------------O
	      |____      germanium diode                      to
		   |___________                             crystal
                   ///////////|========  <-- tune -->       earphone
              _____|-----------
              |      loopstick with sliding core
   GND	O-----+-----------------------------------------O 

   Loopstick is miller 2002 or equivalent      (surplus stores)
   (I was able to get some similar inductors at a surplus store,
   and remove some of the coil windings until I was able to receive the 
   broadcast band.)
   Earphone is high impedence crystal earphone (antique radio supply)
   Germanium diode is type 1N34a or equivalent (antique radio supply)

   The rocket case is a water-powered toy rocket 
   available at K-Mart for $1.67.
   Using a bandsaw cut off the bottom nozzle and about 
   1/2 inch of the fins allowing the rocket to stand up
   by itself.

   Before cutting the top half of the rocket off, make
   a small mark on one side across the area to be cut,
   so you can align the top when you re-attach it.

   Cut the top half of the rocket off with the bandsaw
   to allow the parts to be installed inside. The top
   will later be glued back on with plastic cement.

   Drill a small diameter hole in the nose tip of the
   rocket (drill from the inside) for the tuning rod of
   the loopstick.

   Drill a small hole in the side of the bottom half of the
   rocket body for the earphone wire and the antenna wire
   to pass through. Don't forget to knot the wires on the inside 
   of the rocket so it won't pull out.

   Solder the antenna wire to the loopstick, and the earphone
   leads to the diode and the other side of the loopstick, and
   install the loopstick into the nose cone of the rocket.

   The loopstick is installed by hot-glueing it to a 1/2 inch 
   diameter washer with a large enough hole for the loopstick
   to poke through. Once the loopstick is attached to the 
   washer, the washer is then hot-glued to the inside of the 
   nose cone with the tuning rod sticking through the hole in
   the the nose cone tip.

   A small (1/4 inch) wood or plastic bead available from craft
   stores is glued on to the loopstick tuning rod end after it
   is installed into the nose cone.

   Now is a good time to connect an antenna and check your wiring
   for accuracy!

   If all works well, it is time to complete the assembly of your
   Crystal Rocket Radio.

   The top half of the rocket is now cemented to the bottom half
   using plastic model cement.

   Let dry for a couple hours, and enjoy!

   My radio receives 3 stations here in Seattle.





Gary Litwin
glitwin@craysea.cray.com