TopBand: Inv-L Tuning/ Capacitors

Jeffrey Maass jmaass@freenet.columbus.oh.us
Wed, 1 Oct 1997 14:13:08 -0400 (EDT)


I have had a motorized UCSL-100 vacuum variable capacitor given to me, and
I'd like to use it at the base of my inverted-L, if practical.

I believe that W1BB recommended a length of 160 (or so) feet, with a
capacitor at the base to tune. What's the current thinking? Should I make
it just a bit over a quarter-wave, and use the capacitor? Make it 5/8-wave
long? 

I've seen values of 850 pF for the capacitor used on the W1BB-type Inv-L:
can I get away with 750 pF of fixed capacitoance + the 100 pF  vacuum
variable and still cover the range 1.8-1.95 MHz?

Or should I just tune the inverted-L for center of band and use the
capacitor in some kind of remotely-tunable L-network?

73,

Jeff Maass       (jmaass@freenet.columbus.oh.us)      Amateur Radio K8ND
      USPSA/IPSC # L-1192   NROI/CRO          NW of Columbus Ohio
      25000 Members in 2000!


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