January 29, 2012

Project: Anderson Powerpole to 2.1mm Connector Pigtail

When building our KN-Q7A Single Band SSB Transceiver Kit we realized after starting that we lacked the necessary power 2.1mm connector to supply 12v to the power jack.

From a design standpoint we decided to construct an Anderson Powerpole to 2.1mm connector pigtail.  This was a natural choice since we previously converted our radios and cabling to Anderson Powerpoles.  A 2.1mm connector to Anderson Powerpoles will give us maximum flexibility to move the radio from one power source to the next (e.g. battery, car power, shack power supply, bench power supply, ....).  The commercially available Anderson PowerPole to 2.1mm cable costs at the time of this writing about $5.00 plus shipping. 

We decided it would be more ecconomical and far more fun to build the pigtail cable ourselves.  A home-brew cable would also give us an opportunity to incorporate a few improvements in design over the commercially available cable.
One of the improvements we wanted to include on the cable was an RF choke.  We decided to add a ferrite (from the junkbox) to the pigtail to help minimize RF travelling over the power cable.  This would potentially be useful when running the radio from a car or other noisy source.

Pigtail construction in progress with ferrite bead
To protect the ferrite bead and assure the wire loop would stay nice and tight we added heat-shrink tubing around it.  We also added a section of heat shrink tubing to the end next to the Anderson Powerpole connector as a strain relief and to dress the cable nicely.

Finished 2.11mm to Anderson Powerpole Pigtail with ferrite bead for RF supression
After completing the wiring we ran a quick series of continuity tests with our multimeter to verify that the cable was fully functioning and without any shorts or other defects.  For our project, we needed the 2.1mm center to be positive.
The final product came out really looking and functioning perfectly and cost very little.  Having a completed cable enabled us to continue on building and testing our KN-Q7A Single Band SSB Transceiver Kit - Step 2: Audio Amplifier.

By Michael W. Maher (NJ2X)
Other related articles on NJ2X.COM:

© Michael W. Maher and NJ2X.COM, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.