ORIGINAL MESSAGE:
On Wed, 16 Apr 2008 06:43:26 -0700, Jim Lux <jimlux@earthlink.net>
wrote:
>BTW, after some hours of grinding the optimizer in 4nec2 I've not been
>able to find a set of lengths for 3-5 parallel dipoles that provides a
>good match on ALL HF hambands without a tuner.
------------ REPLY FOLLOWS ------------
Good point. I should have mentioned my parallel vees easily tune to 30,
17 and 12 meters with a tuner. My tuner is a homebrew T-match using two
1000 pF vacuum variables and a 20 uH roller inductor, with turns
counters on all three elements. Works like a charm. I use it mostly on
80 meters where the minimum SWR is 1.5:1 without it, or on the other
bands when I get far off resonance. On 160 and 40 I was able to trim the
vees to a perfect 1:1 without the tuner.
If anyone is considering building such a tuner, a 10 uH inductor would
be more than enough. The max inductance I need on any band, including
160 meters, is about 7-8 uH. Remember, this is for coax-fed vees or
dipoles only. If you are planning on balanced lines, you might need more
range of inductance.
73, Bill W6WRT
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