Offset Attenuator v1.0

by SmittyHalibut.

2 layer board of 2.58x0.97 inches (65.41x24.66 mm).
Shared on November 20th, 2014 05:07.

A 4MHz offset attenuator for radio direction finding.

Mostly based off this design with a few modifications:

  • 3 position switch: Off, On (10db pad bypassed), and On with 10db pad.
  • Better filtering LPF from 4MHz oscilator to mixer section, an LC instead of RC (replaced 100ohm resistor with 15uH inductor.) Should leak less RF.

The board is designed to fit into a ½" conduit pass-through box, like what you might put on the handle end of a measuring tape yagi (Google it; there are MANY plans and designs for them.)

Only parts that are “special” are:

The rest are just standard cheap-o resistors, capacitors and 1N4148 diodes, with values as labeled on the board.

Easiest way to get a hold of me is probably on Twitter: @SmittyHalibut. Shoot me a note with your experiences if you use this board! Thanks!

Order board. Download. Permalink. Embed order link.

Copy this HTML into your page to embed a link to order this shared project