I finally got time to try cutting a small ferrite bar on my
diamond-bladed tile saw. I'd been cautioned to use plenty of water
so as not to damage the annealing. I did. It cut VERY easily and
cleanly. I could tell no rise in temperature by touch, immediately after
making the cut. It worked like a charm. Thanks to everyone who made
suggestions last week.
Someone asked why would you want to cut a ferrite bar??? Well, one reason
might be if you were making a large bundled bar antenna where the final
bundle is several bars in cross section (usually 3 or 7) and several bars
long. One way to help the lines of magnetism not see the end (butt)
joints between individual bars is to stagger the ends at least one bar
diameter... two is probably better. If you stagger the ends of the
individual bars, you end up with a ragged end at the front and back of
the bundle.... so, you might want to cut things off flush, for magnetic
as well as aesthetic reasons.
Another reason...mine in this case... is jamming a large high-grade IF
filter in a little bitty radio... the E100. Since I intend to DX with
either a larger ferrite bar or with a normal outside antenna, the stock
bar is only needed as the core of an inductive coil arrangement for the
outside antenna. It could also be used to pick up local stations when no
outside antenna is attached. Neither of those functions require the size
bar that comes in the E100 and I desperately need the space for the IF
filter, so, I just cut an inch off'n mine and I'm happy as a clam.
Cutting the 3.3 inch bar to 2.3 inches did not change the inductance of
the coil much, so sliding the bar a little farther to the center corrects
the alignment. Losing 1/3 of the bar length should reduce sensitivity and
nulling capability somewhat, but in this application, that is plenty
OK.
If you've read this far and don't own a tile saw, you'll be happy to know
that Lowe's stores have them to cut customers tile and I'll bet that Home
Depot does, too. Likely catching the staff at a quiet time and crossing
their palm with a bit of silver could get your bar cut very nicely.
Thanks again for the suggestions!
John B.
Orcas Island, WA, USA
Rcvrs: WiNRADiO 313e, Eton e1, Ultralights
Antennas: Two 70' x 100' Conti Super Loops, West and Northwest
