VE6AB Mobile Ops

A multi turn choke

So whats going on here you ask....well what we have is the shunt-coil used for matching purposes, mounted in its waterproof housing at the upper right of the photo. The shunt-coil is teed into the RG8X coax with a PL 259 Amphenol-Tee, and the the PL259 connectors are wrapped with rescue tape, keeping any moisture out. I replace the sealing tape once throughout the year, in the spring. Upon checking on the condition of the PL 259 connectors, I then re wrap the connectors with new sealing tape..

Next in line are 6 turns of the RG8X coax routed through two mix-31 split-beads, to control common mode currents flowing on the surface of the outside of the coax shield.
There is a always the possibility that there will be some common mode currents in any mobile antenna system, and this is the best way to approach this problem in a mobile environment.

I am using the same type mix 31 split beads for the gearmotor control leads as well, The gearmotor wiring with 6 turns through a mix 31 split bead, is visible in the lower left of the photo.

I purchase all my mix 31 split beads on line from DX Engineering, and the split beads are available in various sizes, although you will get more milage out of the larger inside-diameter split beads, as 4 turns through 1 bead, is the same as the single coax routed through 16 beads. The turns should be evenly spaced, and not overlapped. Otherwise you will reduce the effectiveness of the choke.

Shunt coil here....

http://www.jerryclement.ca/HamRadio/HamRadio/i-NQzSmGB

Making connections.....

http://ve6ab.blogspot.ca/2015/02/ham-radio-mobile-endeavours.html

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