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Old September 22nd 03, 01:55 AM
Jim Hampton
 
Posts: n/a
Default CB Antenna help

RF grounds and DC grounds are not necessarily the same. You can feed a
grounded vertical part way up with good results. One could have an RF
choke in a circuit which is essentially a short circuit to DC, but is an
open circuit for RF.

Interesting point: if you take a 1/4 wave section of coax (taking into
account velocity factor) and solder the inner conductor to the braid, you
will measure zero ohms at the far end on an ohm meter. If you try and feed
rf into it, it will appear as very close to an open circuit! Should you cut
that short off the end, leaving it open, it will test open with a meter, but
will be a short circuit to the rf.

Things ain't always what they appear to be


73 from Rochester, NY
Jim



"SNA" wrote in message
news
I have a question which I need to ask. This may sound stupid but I just
don't understand. I have a cb base antenna that is a "DC Grounded "

antenna.
When I hook up a ohm meter to it at the coax end ...it shows a direct

short.
The swr on the antenna is excellent.....so how can this be?
Any help will be appreciated




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