In a message dated 16.11.99 08:52:03 Pacific Standard Time, K7GCO writes:
For those who need some help on grid dipping open wire or coax line here
is a short course.
K7gco
<< Short out both ends, tie one end to a wooden object with string, pull it
tight 4-5' off the ground and GD the other end where it's half wave, a full
wave on and on. Listen for the dip frequency in a receiver and record it.
Or tie the unshorted end to a wooden support and GD it at the shorted end at
it's 1/4 WL frequency and all odd 1/4 WL frequencies. Use 1/2WL in ft' =
492 xVF/Mhz. You can calculate the VF also. VF=ft x MHz/492. Use the least
perceptible dip--loose coupling and measure the frequency. You can lay coax
on the ground or coil it.
I had an article in CQ 30 years ago on how to grid dip coax. Things are
packed here so I don't have a copy handy.
k7gco >>
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