Hoping to reduce some interference on MF & LF

A device that uses two receive antennas to null out the noise on the lower Amateur bands.

Keep it simple...

When you try to listen on part of the radio spectrum, sometimes there may exist a source of local interference that needs to be eradicated. Enter the X-Phaser. This device employs the use of two receive antennas, usually verticals, and the phase relationship between the two antennas is varied so that the interferer can be cancelled out or at least minimised greatly, so the wanted signal can be heard. That's the theory. Practically, a number of manufacturers have made various products that are available for various costs.

This build was of a simple design that suited my needs to block a local interference signal in a nearby residence area. It was cheap and easy to build with minimal components. It may not have all the bell and whistles of other designs, but it was adequate in my particular situation. The antennas were similarly offset in direction to the noise source and was therefore able to greatly reduce the offending noise source. Probably a notorious plasma TV and or power supply. The noise lasted for several months before it stopped - probably died! Wahoo.

Here are some photos of my build. Not as speccy as the photos in the reference article linked below. A schematic is included in their document. Enjoy. YMMV.

Front view

 Just three front panel controls.

Rear view

 DC in, 2 Rx inputs, & 1 Rx  output.

X-Phaser schematic


Inside - rear panel

 Rear panel connections.

Inside - front panel

 Front panel wiring.

Internal board layout

 Showing internal wiring.

Useful Links


VK5FQ website
12/02/14 Start build of new website.


Steph - VK5FQ
Adelaide, South Australia,