Radiola 28 Loop Antenna Revisited
 

The last episode left off with Winky Dink looking for the dimensions to make a reproduction of the rotating loop antenna. After a year of intense exploration I still don't have the dimensions I wanted. But I did find some fascinating facts that you need to know.

First, I found three variations of loop antennas for the Radiola 25 and 28. One of the variations is incompatible with sets designed for either of the others.

I don't imagine anyone else will ever need to do this, but here's a brief essay on the fabrication--just in case the techniques might be useful in some other project.*

1. My first obstacle was figuring out how the antenna plugged into the socket.

https://lh3.googleusercontent.com/-_...8%25201000.jpg

2. I had never seen the plug-end of a loop antenna until I found this in an Antique Radios forum post.

https://lh5.googleusercontent.com/-S...8%25201001.jpg


3. I found that PVC conduit was a perfect fit for the socket (after some vigorous sanding). I made cutouts to accommodate copper spring contacts to match the socket.

https://lh6.googleusercontent.com/-A...8%25201002.jpg

4. I found a handful of loose contact springs in a junk box.

https://lh5.googleusercontent.com/-y...8%25201003.jpg

5. Soldered a lead to each contact and secured them with JB Weld.

https://lh6.googleusercontent.com/-P...8%25201004.JPG

6. After a quick finish with sandpaper…

https://lh4.googleusercontent.com/-n...8%25201005.jpg

7. …it fits like a plug in a socket.

https://lh5.googleusercontent.com/-p...8%25201006.jpg

Since the plug doesn't match the original and the loop wire is impossible to duplicate (Rayon covering on bare, stranded wire), I've give up the idea of making an accurate reproduction. Instead, I've made some templates for the base and cap of the antenna frame with dimensions designed to give a good esthetic, and I'm waiting for a call-back from my woodworking guy to see if he wants to work on this.

* Do not call Julian Assange. I don't want this to show up on WikiLeaks.

Excellent work. And, as usual, good show: the medium is the message.