Is that article available on line ?
Thanks, Dick, W1KSZ> Date: Thu, 4 Dec 2008 18:22:55 -0800> From:
n6ki73@gmail.com> To: w7why@verizon.net> CC: towertalk@contesting.com> Subject:
Re: [TowerTalk] Inverted L Tuning Question> > The issue with teh AM BC Strong
Signal interference is addressed in> the Nov/DEC NCJ> ( National Contest
Journal ) magazine article> ..and article uses exact same antenna analyzer as
Dick is using !> 73, Dennsi N6KI> > On Thu, Dec 4, 2008 at 6:09 PM, Tom Osborne
<w7why@verizon.net> wrote:> > > Hi Dick> >> > You can get some screwy readings
if there is a BC station nearby. I can't> > even use my analyzer here on my 160
inverted L because of RF from the> > local.> > I have to use the SWR bridge in
the shack. 73> > Tom W7WHy> >> >> >> > > Hi Guys,> > >> > > I'm trying to set
up a 160-m. Inverted L for ARRL-160 this weekend but am> > > having an
interesting tuning problem. All thoughts appreciated!> > >> > > The Inverted L
is made up of #12 stranded copper wire 136' in total> > > length:> > >
82' vertical and 54' horizontal. The vertical wire is spaced 6' from a> > >
88'> > > self-supporting tower with a Cushcraft XM-240 mounted on top. (XM-240>
> > elements> > > are not grounded) Initial radial system is 2- 135' radials
laying on> > > the> > > ground- not much but two similar radials worked pretty
well on my 60'> > > tower last> > > year as the towers are 150' from a salt
water river.> > >> > > Placing the Antenna Analyzer (AIM 4170) at the base of
the Inverted L> > gets> > > the following measurements:> > >> > > 1) With the
coax braid connected to the tower base which has two 8'> > ground> > > rods:
lowest SWR is 3.9 at 1.776 Mhz and Z = 79.> > >> > > 2) With coax braid only
connected to the two radials (and not the tower> > > base): lowest SWR is 1.62
at 1.614 Mhz and Z = 81.> > >> > > It was my understanding that the coax braid
should be connected to both> > > the> > > radials and the base of the towers
gnd system, but as you can see the the> > > minimum SWR
and resonant freq. go crazy when I do.> > >> > > Any recommendations what I
can do to get it working before tmw night?> > >> > > 73,> > > Dick- K9OM> >> >
_______________________________________________> >> >> >> >
_______________________________________________> > TowerTalk mailing list> >
TowerTalk@contesting.com> >
http://lists.contesting.com/mailman/listinfo/towertalk> >>
_______________________________________________> > > >
_______________________________________________> TowerTalk mailing list>
TowerTalk@contesting.com> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|