[Antennas] Dipole SWR

Sat, 15 Jun 2002 00:33:06 -0400

 > I just moved my 75 meter dipole from 25 feet to 60 feet at the apex & ends
 > are at about 45feet .  The problem is the SWR at the lower height was about
 > 1.2 ...... But now that I raised the antenna , the lowest it goes is 1.6
 > ..... is this because the dipole is starting to have it characteristic 72ohm
 > impedance as I go up in height ??  If so can I use a 75ohm quarter wave long
 > coax to match it to the 50 ohm ??

   I am confused, a dipole is supposed to be about 73 Ohms and an inverted
"V" is supposed to be near 50 Ohms.  If you are using a dipole with 50 Ohm
transmission line and you change it into a inverted "V" the match
should have gotten better.
I will admit, I never got a better match to 50 with a "V" than to 75,
but that is how the theory goes.

   I suspect the proximity to the ground had untuned the dipole and it
comes closer to free space tuning as a "V".  Do you have resonance
measurements for both condx.?  (the edges of gud swr will do)

        73 (= Best Regards) de: Ron [email protected]
     100% LINUX, since July, 1997   SENT Time and Date are UTC
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