But if Tom took the reading with the coax disconnected, he wouldn't
be connected to the R V ground so shouldn't have seen the results he
saw. And for the life of me I don't understand how mere proximity
could cause a direct D C short.
Puzzling.
PatAt 05:24 AM 8/21/2012, you wrote:
>Tom,
>
>If all the components of the G5 are insulated, I don't see how the antenna
>being in the proximity of the metal roof or one of the legs wrapped around a
>metal ladder leg could cause continuity between the two sides of the
>antenna. I do believe that the antenna wrapped around the ladder leg would
>most definitely detune it though.
>
>Now, if the ladder is connected to ground, perhaps through the metal frame
>of the R V and the AC power system, and your G5 was actually connected to
>the ladder through a break in the insulation on the antenna wire and the
>shield side of your coax wiring in your RV is connected to that same power
>line ground than you could read a possible short if the ladder side of your
>G5 was the center of the coax feed line.
>
>I don't know anything about RV construction, however if the AC receptacles
>are mounted in metal electrical boxes and the electrical boxes are mounted
>to a metal RV frame then the whole metal frame of the RV would be connected
>to the power line ground because the mounting ears of normal household type
>receptacles are connected to ground.
>
>I know that was poorly written, but read it slowly and I think you will
>understand my thoughts.
>
>73
>
>Howard #3
>
>
>
>
>
>----- Original Message -----
>From: "Tom Behler" <[log in to unmask]>
>To: <[log in to unmask]>
>Sent: Tuesday, August 21, 2012 4:42 AM
>Subject: Re: G5RV Update
>
>
> > Great suggestion, Howard, and I will definitely carry it out.
> >
> > Thanks very much.
> >
> > Tom Behler: KB8TYJ
> >
> > ----- Original Message -----
> > From: "Howard, W A 9 Y B W" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Monday, August 20, 2012 9:54 PM
> > Subject: Re: G5RV Update
> >
> >
> >> Tom,
> >>
> >> While you have the antenna down, do the following:
> >>
> >> 1. Check for continuity from the center pin of the coax connector on the
> >> coax pigtail to each end of the antenna's horizontal elements there
> >> should
> >> be continuity to one of them.
> >>
> >> 2. Now do the same from the shield side of the coax connector on the
> >> coax
> >> pigtail and you should have continuity to the end of the opposite leg.
> >>
> >> Alternatively, you could connect the ends of the antenna horizontal legs
> >> together if possible and than check for a short across the coax connector
> >> on
> >> the end of the coax pigtail.
> >>
> >> I am only suggesting this so that you will know that there are no breaks
> >> in
> >> the connections at each end of the ladder line. Can only do this on the
> >> ground. Impossible to do with the antenna in the air.
> >>
> >> 73
> >>
> >> Howard #3
> >>
> >>
> >>
> >>
> >>
> >>
> >> ----- Original Message -----
> >> From: "Tom Behler" <[log in to unmask]>
> >> To: <[log in to unmask]>
> >> Sent: Monday, August 20, 2012 8:05 PM
> >> Subject: G5RV Update
> >>
> >>
> >>> Hi, all.
> >>>
> >>> Well, tonight, with a little bribery in the form of an ice cream cone on
> >>> the
> >>> way out to the RV, the XYL and I took the trip to retrieve the suspect
> >>> G5RV.
> >>>
> >>> The antenna is now right here in front of me, and guess what I found!
> >>>
> >>> With the antenna taken down, and now free of any connections, there is
> >>> an
> >>> open circuit across the PL259! In other words, no continuity across the
> >>> connector!
> >>>
> >>> So, to me, this would indicate that the antenna is sound electrically.
> >>>
> >>> Before putting it up again, of course, I will check all connections, but
> >>> this, to me, is very encouraging.
> >>>
> >>> It also indicates to me that there is a problem somewhere in my feed
> >>> line
> >>> system, hopefully not in the feed line that runs underneath the RV.
> >>>
> >>> At least, though, I think I've now got the problem isolated in a major
> >>> way.
> >>>
> >>> Will keep everyone posted, but, unless I'm deluding myself, I'm now
> >>> greatly
> >>> encouraged.
> >>>
> >>> 73 from Tom Behler: KB8TYJ
> >>
|
