[sci.electronics] Car ground for mobile CB antenna

hleaves@ruby.vcu.edu (EAVES,HUGH) (01/12/91)

I always seem to get great standing wave ratio's for my car's CB antenna
(1.2-1.7 range). How does the car act as such a good ground for the antenna?
From what I've been reading here, the ground plane has to be tuned or very
large. My car certainly isn't 38 feet across!

Hugh

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** Hugh L. Eaves                      ** Internet: hleaves@ruby.vcu.edu      **
** Medical College of Virginia        ** Bitnet: hleaves@vcuruby             **
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tad@ssc.UUCP (Tad Cook) (01/14/91)

In article <61302@brunix.UUCP>, hleaves@ruby.vcu.edu (EAVES,HUGH) writes:
> I always seem to get great standing wave ratio's for my car's CB antenna
> (1.2-1.7 range). How does the car act as such a good ground for the antenna?
> From what I've been reading here, the ground plane has to be tuned or very
> large. My car certainly isn't 38 feet across!

38 feet?  That is over one full wavelength at CB frequencies!

Considering that a quarter wave at 11 meters is only about 8 and a half
feet, it is not surprising that the car body would provide a reasonable
ground for the antenna to work against.

I run a mobile station on the 20 mtr ham band, and get great results,
although the same size antenna would be more efficient on 11 mtrs.



Tad Cook
Seattle, WA
Packet: KT7H @ N7HFZ.WA.USA.NA
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