One of the reasons I have mot gone to high power on 160 is the cost of
capacitors for my omega match - at least $300. Anyone know of any
workable alternative? I remember someone writing about using coiled-up
RG-8, RG-213 or maybe Teflon coax. Where can I find more information?
Coax isn't the best for two reasons:
1.) Transmission line effects increase voltage at the open end. This
aggravates arcing issues
2.) They are lossy
Here's something to think about, Pete. The voltage across a capacitor is I^2
* Xc
So if you have a shunt feed and use a long, thin, wire....you not only
decrease bandwidth and efficiency, you also increase the voltage. A thin
shunt feed wire requires higher Xc (lower capacitance), and that makes
voltage increase and BW narrow.
Use a wire cage and tap the shunt wire down at a 50 ohm point, and voltage
goes way down. Do it the lazy way and use an omega match, and you give up
bandwidth and need higher voltage parts.
73 Tom
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Topband Reflector
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