You looking for a mobile scanner antenna.......

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Skypilot007

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What frequencies are you monitoring with this antenna? It looks like a straight up 1/4 wave VHF antenna.
 

W2NJS

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DDan wrote above:

"It's only half of a 1/4 wave as it's missing a groundplane."

That is flat-out wrong information. The ground plane of a quarter-wave antenna makes the antenna, in theory, a half-wave antenna.

Quarter wave antenna formula for 146.000 mHz:

468/146=3.21 feet for a half-wave, or 38.47 inches, which translates to 19.23 inches for a quarter-wave.
Or you can figure the quarter wave directly by using 234 instead of 468 in the formula.
 

W6KRU

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DDan wrote above:

"It's only half of a 1/4 wave as it's missing a groundplane."

That is flat-out wrong information. The ground plane of a quarter-wave antenna makes the antenna, in theory, a half-wave antenna.

Quarter wave antenna formula for 146.000 mHz:

468/146=3.21 feet for a half-wave, or 38.47 inches, which translates to 19.23 inches for a quarter-wave.
Or you can figure the quarter wave directly by using 234 instead of 468 in the formula.
You are correct. You phrased it more correctly.
 
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