On 9/18/2018 4:19 PM, Joe Subich, W4TV wrote:
2) use a 4:1 auto-transformer at the feed point - your antenna
analyzer says the real impedance is about 15 Ohms. A 4:1
auto-transformer will get the SWR down to about 1.2:1.
Generally speaking, you will get a wider bandwidth with
a autotransformer than you will with an LC network. To match
15 ohms to 50 ohms, you can wind 7 turns on a high-mu toroid and
drive the whole 7 turns from the radio. The antenna is
tapped down to 4 turns. 7/4 squared is close to 50/15.
Less than 1.1:1 SWR.
BTW, an autotransformer automatically DC grounds the antenna.
Rick N6RK
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