Re: [IRCA] Trip prep..

["Craig Healy" <bubba@xxxxxxxxxxxxxxxxxxxx>]

> Can you point us to a link describing your untuned ferrite?  Or send a
> short description?

Yup.

http://www.am-dx.com/ferrite_antenna.htm

Not much to it.  A big hunk of ferrite in a plastic pipe, just as it was
shipped from Stormwise.  Wrapped a half dozen turns of #14 wire around the
middle and ran that to an SO-239 jack, with the leads twisted and run twice
through a big ferrite bead to isolate it.  Stuck the thing on a camera
tripod and viola!

I brought to to the south coast of RI today to do a test run before I head
to Maine.  All daytime reception, but it worked very well.  It nulls quite
nicely.  Tuned down to LW and heard the usual local beacons.  Went as far up
as 10MHz WWV, but it does start to get deaf above the 80m ham band.  I was
able to null nearby WLKW-1450 to get the ESPN station in Atlantic City just
fine.  Same with 1340.  Could null WNBH-1340 to get the Ocean City station.
Philadelphia on 1210 was strong.  Couldn't get KYW, though.  Had an unid'ed
station on 900, but probably New Hampshire.  Got a SAH on 530, some of which
was probably the beach TIS station just east of Fall River, MA.  1620 had
what was likely the pirate from Brockton, MA.  Not strong enough to pick out
more than a bit of music.  Sounded island-type, but likely way too early for
WDHP.  Bottom line was that the sensitivity seemed adequate with the single
RPA-1.

I did try wrapping around 36 turns of wire connected to a variable capacitor
to see if tuning it would help.  Unfortunately, close-wound turns have too
much capacitance and loss.  Didn't work.  I may try a section of premade
coil of around 3" diameter and try to tune that.  To be honest, the only
reason I'd tune it is to raise the output and try to eliminate the need for
the RPA-1 preamp.  Ran the setup for three hours today, preamp and all off
the 12v battery.  Worked fine, no sign of low voltage.  A three hour session
is fine for me.  Even if it weren't, the batteries are only about $25.  Add
in a bit of wire and a three dollar connector, and it's still cheap.

I think it will work fine next week.  If not, then I guess I'll just have to
enjoy the vacation..  (sigh)

Craig Healy
Providence, RI

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