RF Toroid Calculator by VK3CPU
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RFI/EMI Solutions from KHz to GHz
RF Toroid Calculator by VK3CPU
For best results support center at 30+ feet and ends over 15 feet. Angle of feed each side must be great than 45 degrees or 120 – 180 degrees total between each side preferred. Any length of 50 ohm feed line ok (from the matching unit) but longer feed lines over 50 feet may show reduced SWR on some bands due to losses in feed line and soil conductivity, nearby objects, etc. Due to local ground conditions, antenna height and feed line length, SWR may vary from samples shown and an antenna tuner may be required or some bands to bring SWR at end of feed line to acceptable levels.
Antenna Length Note:These antennas are shipped from the factory with each side at 46 feet long (92 feet total) so that you may adjust(shorten) the length for your personal installation.The SWR graph shown for this product is for a side length of 44 feet as this length provides a lower SWR in the 17 meter band than the 46 foot length. The longer 46 foot length tends to shift the SWR curves to the left (lower frequency) which can sometimes be offset by reducing the length of the ladder line (up to 2 feet max). Each antenna installation is unique – try the antenna lengths as received and shorten the wire length by bending back the wires on themselves at the ends as needed.
Use an antenna tuner for 80, 30, 15 meters and reduce power if balun saturation occurs.
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Insulators may be black, grey or white depending on stock at hand when order is placed. Wire is stranded, AWG#14, insulated and black or grey color.