Correction of my error.
Anyone interested can download program L_TUNER from website below.
The antenna input impdances obtained from program TUNEHALF can be
inserted in program L_TUNER and the L and C component values compared
between one type of tuner and the other.
Remember that with the L-tuner both L and C are variable. With the
parallel L and C tuned circuit, in general, only C is variable and
impedance matching is accomplished by tapping up the coil. ( or by
varying the turns on a link-coupling which, by the way, confers other
advantages.)
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Regards from Reg, G4FGQ
MUCH better Reg.
At one time, my 160 meter half wave was fed with a parallel tuned circuit
using a huge roller inductor (5 inch diameter, foot long surplus thing) I
used the same motor driven vacuum variable to obtain resonance and the
roller "tap" was only to obtain the 50 Ohm match. Was a fine 160 meter
antenna, but my 40 meter quad was an eyesore and difficult to maintain, and
I had nothing up for 80. Swapping out the inductor for a piece of Airdux and
tapping that for 3 values of inductance and selecting those with an old
Ledex motor driven rotary switch gave me all 3 bands with an "L" network.
Difficult to accomplish with a parallel tuned circuit without appreciable
additional complexity, never noticed any difference in performance on 160
meters. We now have two copycat antennas, up for several years. W4GCK and
W1TRF, both are as well pleased as I have been. GCK and I have a directional
antenna for the higher bands, TRF uses his on all bands.
Regards
W4ZCB
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