Topband: Trap for 160m/80m inverted L

Bill Tippett btippett at alum.mit.edu
Fri Dec 9 11:33:03 EST 2005


N8BM wrote:
 >Is there anyone out there that has a KW80C not connected that could 1)
measure the resonant frequency with a grid dip meter and 2) measure the
length, diameter, and TPI of the coil?  With that I could calculate the
inductance and then the resonate impedance on my own.

         If you plan to run the legal limit, I would not
waste my time with the KW80C.  I had a 160/80 dipole
and went through 2 sets of those traps until I built
my own using RG8X on PVC forms.  There was a QST
article about this several years ago, and I believe
it may have included the L and C of the traps, but
it definitely included a chart with the number of
turns required for various coil form sizes.  BTW I
had the same problem with the 80m trap in a Battle
Creek Special I borrowed when first getting on the
air when I moved to NC.  W8UVZ or K1ZM can give you
the dimensions you need and you should not have the
problems the KW80C has.

                                         73,  Bill  W4ZV




More information about the Topband mailing list