I used the sleeve approach on the 1.4" stacked ferrite rod. I have a whole bunch 2" clear plastic pill bottles that worked perfectly. 2 coils wired in series for VLF and parallel for MW with a center one contra wound. It worked very well with just a cap across it or even better as a loop head for the palomar.
That's a very nice mag loop for the money. I'd like to get one for T/ R someday being into portable Ham Radio..
My loop amps included the Palomar, which I made my own plug-ins for and a Quantum, both of which I sold along with the plug-ins. Still have my Ramsey Signal Magnet I built from a kit many years ago that first got me started. Still into ferrites - now it's for Ham Radio. I build and sell Baluns and Ununs using toroids and beads.
Was using powdered Iron cores but found ferrite works better
John
KG6ZBN.?
