Ships quickly: http://kitsandparts.com/toroids.php Steve WB6RSE On Aug 4, 2014, at 2:54 PM, Hugh Valentine <hsvdds at juno.com> wrote: K9YC touts the benefits of the 2.4" O.D. Mix #31 Core. Anyone know a good source? I bought a hand full from Arrow last year, now theirs are on back order. Other sites seem pricey.