This should be on the one-offs page since it is certainly one of a kind. But it was a big enough project to deserve its own page.

I first acquired this 1950’s radio signal generator built for the Navy in 2016 from a back shelf at the awesome Skycraft Parts & Surplus in Winter Park. Florida. I detailed the disassembly of the unit and my intent for it in a older post.

Then is sat on a shelf for three years, as these thing sometimes do.

I finally got the bit between my teeth to finish it for MakerX 2020.

First, here are a couple videos of the finished project. It’s all themed on making a prop that might appear in a classic scifi movie operate as it might have in scifi world. It includes video and sound clips from a number of those movies.

A couple kids playing with it at MakerX 2020:

A full tour of its features:

 

The construction retains most of the original hardware out front, with addition of some blinky lights and the cutout for a fake oscilliscope/monster video display. Inside the box it is controlled by two Arduinos for reading potentiometers  and blinking lights, two Raspberry Pis for reading rotary switches and playing videos and a dedicated sound effects card for reading the big dial and playing sound files. Audio out is from a pair of 10 watt computer speakers.

Out back is a 10 foot power cord hooked to a dual 5v/12v power supply in the case. When plugged in the whole system starts so the Pis have time to boot up. However the front displays and speakers are controlled by the big switches on the front so each user feels like they are turning the machine on and off. I also left a volume control reachable from the back only so I could modulate the annoyance level while at events.

Below are some build-up process pictures.

 

After a brief test with an adult group I took it to MakerX 2020 and let several hundred kids (and some adults) go nuts on it for a day. Not surprisingly, the 1950s hardware stood up to the assault just fine. My work mostly lasted OK. There is one strange problem I need to sort out–the Raspberry Pi running the oscilliscope display will spontaneously reboot after a few minutes if the video screen is shut off (but not the power to the Pi).  The other Pi in the secret peephole doesn’t have this issue. Puzzling, but not to hard to live with for now.