[TowerTalk] 80 meter dipole

Dan Hearn n5ardxcc at gmail.com
Sun Jul 20 22:12:51 EDT 2014


Tom: How high is your dipole? Unless it is well over 1/2 wavelength, the
feed point impedance is probably around 25 ohms. You are feeding it with 75
ohm coax, a bad mismatch. Do you have a line choke at the feed point? If
not, your coax outer shield is probably radiating as part of the antenna.
Sounds like you might need to redesign the antenna.

73, Dan, N5AR



On Sun, Jul 20, 2014 at 5:36 PM, Tom Osborne <w7why at frontier.com> wrote:

> I recently put up a dipole for 80 and used some RG-6 CATV coax to feed it.
>  Good news is that I cut it for 3550 and the SWR is about 1.3:1 there.  Bad
> news is that it stays pretty much the same all the way up the band.
>
> Is the wide bandwildth because the coax is so lossy?  It is the double
> shielded stuff with 2-layers of foil and 1-layer of braid. 73
> Tom W7WHY
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>



-- 
Dan Hearn
N5AR


More information about the TowerTalk mailing list