Waveguide-rule of thumb

Discussion in 'General Electronics Chat' started by metal_militia7, May 23, 2011.

  1. metal_militia7

    Thread Starter New Member

    Jun 13, 2010
    The rule of thumb for calculating the lowest frequency that can pass though a wave guide (rectangular) is given by 30/2a (G Hz) where a is the largest dimension.

    fc = speed of light in cm /2a
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    I've forgotten more than most people ever know about waveguide theory. I was a Mk92 Firecontrolman in the Navy. We pushed a quarter million watts down the plumbing and when needed, we could flood the tube with sulfur hexaflouride gas and push the output up to a cool million watts. With a psuedo random frequency dithering option, we were pretty much 'jam' proof as well. Almost unlimited track while scanning capabilities and dual target designation from one tracker. State of the art in the late 70's and early 80's
  3. BillB3857

    Senior Member

    Feb 28, 2009
    The main thing I remember about rectangular wave guides was that they were equivalent to an infinite number of 1/4 wave shorted stubs in parallel. We just used descant dried and filtered compressed air to pressurize the wave guides on the APS-20 and APS-45 systems on the plane in my avatar. Squadron was de-commissioned in 1965 due to over-the-horizon radar being developed.
  4. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    Isn't it though?