[Antennas] Loading a 90 foot wire on 160
Dave Shrader
[email protected]
2002年5月21日 20:03:38 -0400
ARRL Antenna Handbook, Chapter 6, 18th Edition.
You need about 28 uH to 'base' load your 90 foot antenna at 1.8 MHz.
That is a coil about 6 inches long, 6 turns per inch and 2 1/2 inches
diameter; or, 3 1/2 inches long, 8 turns per inch, 2 1/2 inches
diameter.
This will resonate your antenna. At 90 feet, feed point or base loaded,
on 160 meters the radiation resistance is about 15 to 17 ohms [VSWR of 3
to 1 in a 50 ohm coax system].
If your coil meets or is close to these dimensions then the answer is to
tap the coil at about 20% up from the ground [cold] end. Adjust tap for
best VSWR.
Remember to use a good counterpoise or radial system as appropriate.
73, Deacon Dave, W1MCE
Manager, Textron Antenna Range, retired.
Rob Matherly wrote:
>> Like the subject says, I'm trying to load a 90 foot wire on 160.