Precision Signal Generator Series E-200-C (Boing Boing Flickr Pool)


"Technological Dial-O-Meter Time Machine," a photo taken of a device at the Indiana Army Ammunition Plant and contributed to the Boing Boing Flickr Pool by BB reader EvenShift///3.


  1. Note to analog electrical techno-fetishists: check out Neal Stephenson, if you’re not already addicted.

    Consider this excerpt from the World War Two storyline in Cryptonomicon, in which Lawrence Pritchard Waterhouse and the others members of Detachment 2702 are stationed in the chapel of Qwghlm Castle:

    [Waterhouse returns] to the chapel, where everyone else is sleeping. Enlisted men are in the nave, as befits Marines who are basically a naval organization. Officers are in the transept: Chattan has the south arm of it all to himself, Waterhouse and Root and the SAS and USMC lieutenants have bunk beds in the north. A small moiety of Detachment 2702’s astounding tarp supply has, then, been hung up across the eastern end of the place, partitioning off the chancel, Holy of Holies, where once the Body and Blood of Christ were housed. Now it contains a Hallicrafters Model S-27 15-tube superheterodyne radio receiver using state-of-the-art acorn tubes in its front end, capable of tuning VHF from 27 to 143 Megahertz and of receiving AM, FM, and CW, and including a signal strength meter which would come in handy if they were really operating a huffduff station here, which they aren’t.

    1. Karl, you missed the best bit where Waterhouse uses that receiver and a lead pencil to blow a safe.

  2. Surplus stuff is great. I’ve got a military random noise generator. Don’t know what I’ll use it for. Probably something totally random.

  3. That’s my childhood yer lookin’ at here! (OK, these machines were considered somewhat obsolete even back then…)

  4. I might actually have one of these in my parent’s basement (or a very similar looking sig generator). Might have to go digging at Thanksgiving. It should be known that chickenhead knobs like those cost about $5 each for some reason (can’t wait for my hackerspace’s new makerbot to arrive; specialty suppliers can eat me).

  5. NB: ‘cycles’ = cycles per second = Hertz

    so kilocycles = KHz
    megacycles = MHz
    kilomegacycles = GHz

    I remember that taking me a while to figure out. Don’t use equipment that predates SI units.

  6. So you’ve got your automatic volume control bias and modulation control on the right, but what the heck is “RF control?”

  7. Reminds me of my work-study job in my old college’s physics lab.

    Seriously, I don’t get why this is posted here. Is it really so amazing that some pieces of electronic equipment were manufactured without LCD displays or LEDs?

    Geez. I feel like you’re just trying to make me feel old.

  8. Why on earth call this an “Technological Dial-O-Meter Time Machine” while it simply is a signal generator? At least try to understand a little bit of it’s purpose, get out of the typical steampunk mindset for a moment…

    This certainly is no obscure, ununderstandable device. RF signal generators are still being used today by countless RF engineers worldwide, they just look different, use modern solid state tech and are much smaller.

    It’s even possible that some ham radio operator is using an original device like this at the moment to troubleshoot some DIY project because most of the time they still work and if not, are easy to repair.

    Btw, for more epic stuff with a lot of knobs, analog dials and incandescent indicator lights, just google Racal RA17, or Yaesu FRG-7. Really nice analog stuff :)

    1. Johan,

      My dad still has a signal generator like this. One day when kids were making a lot of noise with an AM radio in the park behind our house we used a roll of speaker wire to turn it into a jamming device.

      Worked wonders.

  9. This is basically a variable frequency oscillator connected to a (weak) RF amplifier, making it a transmitter that you can set to a whole wide range of frequencies.

    One use in a shop would be to tweak radio receivers that needed tweaking. Typically the signal output would be weakly coupled to the ‘patient’.

    It has a -really- wide range from 90kHz (the AM band begins at 540; notice the 550 to 1700 scale?) all the way up to 120MHz (the top of the FM band is 108Mhz). That also covers the original FM frequencies, the lowest (most commonly used) VHF TV channels, and all the ham bands commonly in use at the time.

    Probably quite stable; made like a tank to last forever, the way much gear of that period (1945-60) was … when electronics was ‘way sexy’.

  10. The E200-E200C & E200D were the world’s largest selling service oscillators 1935 – 1968 and were dependable pieces. The E200D is the solid state version and remains extremely popular today, just check ebay and hamfests.

Comments are closed.