D104 Desk Lamp
I got the idea to build a lamp out of an old Astatic D104 microphone from the K9YA telegraph, an online amateur radio newsletter, in an article written by Dick Sylvan, W9CBT. Dick had built a desk lamp out of an old, non-functional D104 microphone. When I saw the article, I just knew that I had to build one for myself.
I have a D104 that I use with my HF rig, but didn't want to use it. I had a couple of old D104's which were given to me, so I had a spare one to work with. I dug them out of my junk box and looked them over to see which one I'd use. One of them was in pretty poor shape, but the other was in good condition. It was a non-amplified mike which means that it didn't have any electronics in the base to remove. I disassembled it and removed the mic element and PTT switch from inside the shaft. I also removed the wires from the base and disconnected the mic cord. I then gave all the parts I would use a good cleaning, since they seemed to have been used for a while but not cleaned. The base of the D104 had a lot of chipping & pitting of the paint, so I sanded it down and sprayed it with black spray paint.
From the hardware store I purchased a length of brass threaded tubing, the standard brass tubing used in lamps. The power cord is fed through the tube and the light socket threads on to the other end. I purchased a light socket, but unfortunately the hardware store didn't have any black ones so I settled for a brass socket. I figured the lampshade would cover the view of the socket anyway. I purchased a small clip-on lamp shade at a department store. The power cord was salvaged from an old appliance.
I took the top part of the mike which held the element and drilled a hole in the top like it says to in the article. I also had to ream out the bottom part of the element holder so that the threaded rod would slide through. Once that was done I cut the threaded tube to length and inserted it into the base of the mike and held it in place with a couple of brass nuts. I then threaded the electrical cord through the base, after first passing it through the spring which went on the original mike cord. This gives the lamp a neat look. I then threaded the cord through the tube. I then attached the shaft of the microphone to the base and attached the PTT rod. The round mike element holder was slid down the threaded tube and attached to the top of the microphone shaft. LIke Mr. Sylvan did in the orginal article, I then slid an old microphone plug down the threaded tube to the top of the microphone and secured it in place with another nut. This hides the threaded tube from view. The additional nut holds everything together. Then I fed the end of the electrical cord through the base of the lamp through the threaded tube and pulled it out the top. I then stripped & soldered the wires and attached them to the connections on the light socket. I then screwed the socket onto the threaded tube and tightened the set screw to hold it in place. I pulled the slack electrical cord through the base and secured it with a couple of screws and flat piece of metal in the base of the microphone which secured the original mike cord. I then reattached the base plate.
Finally, before reattaching the front grill and back plate of the microphone, I cut a small piece of black cloth to fit inside the grill. This was done to preserve the look of the microphone and to hide the brass threaded tube inside the empty mike element. The final touch, of course, was to install a light bulb and then clip the lampshade onto it.
The D104 lamp makes a nice addition to my radio shack and is a neat conversation piece.
