• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
  • Notice: You may not use this site to facilitate the unauthorized selling of copyrighted material including, but not limited to, in the public dxForums, dxGallery, dxChat and private messsages. If you get caught doing this, you will be permanently banned with no second chances. A notice will be placed on the site of why you were banned and any information collected by this site about you will be made known to the copyright holder.


  1. square wave tdr.jpg

    square wave tdr.jpg

    5v square wave TDR using 74AC14 schmidt trigger oscillator.
  2. 2n3904 TDR.jpg

    2n3904 TDR.jpg

    Avalanche pulse generator TDR using a 2n3904 inside a capped off PL-259 coupling ring attached to a TNC to SO-239 adapter (because I didn't have a BNC to SO-239 adapter) with high voltage supply.