Steve, I'm having trouble separating the coax feeder from the 6m quad driven element.
I visited your site to see what info there was on air wound chokes but your page only deals up to 30mhz. Is an air-wound choke feasible at 50mhz?

Sure - it's feasible; it's just that air-cored chokes are so High-Q that you only have to change the winding diameter a small amount, or add an extra turn, and the thing no longer has high impedance where you want it. In fact, the only reason I included any on my chart was to demonstrate how narrow band they are!

All that said, 4 turns of Rg213-size on a 4" diameter should be about right for 6m.

73,
Steve G3TXQ

Cheers Steve I'll try that tomorrow night, it'll tide me over until I get a load of clip-on ferrite cores.