Tuesday, 4 December 2012

Finished Project : Single Coil Z-Match

On a bit of a roll here putting up pictures and brief descriptions of recently(ish) completed projects.
Pictured below is my Single Coil Toroidal Z-Match which follows a design by Lloyd Butler VK5BR .
This uses a T200-2 toroidal core and a couple of receiver type variable capacitors which allow a max input power of about 50 watts CW . This depending on the aerial in use i.e. short doublets may cause problems on lower bands but I used a 50ft doublet on 80m with no problems, though down on efficiency.
A hole was cut in the box lid to allow clearance for the capacitor vanes and a perspex cover added to keep dust out etc.
Vernier drives are great for this application but hard to get at the right price these days. Got these at Maplins years ago.
Hope to build a higher power version with air-cored inductor soon..

Single coil toroidal Z-match (QRP)


  1. Very nice built Ian. The clear lid is a little unfortunate, but the piece of plexiglass does the trick. 73, Bas

  2. Hi Bas ,
    Glad you like it.
    The box was left over from a failed transverter project , it has a few drilled holes out of view too.
    Works well though.

    73 Ian

  3. Nice! The clear lid lets you see the innards! I'm assuming you did that because the tuner wouldn't operate properly with an all-metal lid?

  4. Hi Dave,

    The capacitor vanes would not clear the lid of this recycled project box, a window seemed a neat solution and keeps the dust out :-)