Re: Toroid material for QRP HF tuner: "2" or "6"?

Chuck Carpenter


I tend to build z-matchers to cover low HF and hi HF. One covers 160 thru 20 meters with type 2 cores. Others covers 40 meters thru 10 meters using type 6 cores.

Also build a few single band versions such as 10 and 6 meters using type 10 cores (black).

I like the designs from Charlie Lofgren, W6JJZ, and find them to have a wide impedance matching range and good measured efficiency.

You can find his designs in ARRL Antenna Compendium #5 and here:

For measurements the AI1H procedure found in QEX for Sep/Oct 2003

and PDF here:


Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX

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