As I said before. It's a choke.
To provide a DC path to ground for static.
73, Jim. W7RY
On Mon, Aug 8, 2022, 2:05 PM Gene Smar via TowerTalk <
towertalk@contesting.com> wrote:
> Jim WA7DUY:
> Are you attempting to get a ground-plane vertical operating as an
> elevated 1/4WL antenna using that base? Or are you ground-mounting the 20M
> element using the base just to hold the element onto a ground stake?
> Answering those questions will clarify for us what you're attempting to do.
> I have a similar 11M GP antenna from Radio Shack that I cut down by
> 11 inches (radials, too) to operate on 10M back in the late 70s. I no
> longer use it but it was easily found in my garage today. I just now
> measured the DC resistance of the base connections. The SO-239 center pin
> to insulator set screw measures zero Ohms (as it should) on my el cheapo
> VOM; it measures about an Ohm between the SO-239 threads and the set
> screw. So there is something there between the center conductor and the
> mounting base; not sure what it is, though.
>
>
> 73 deGene Smar AD3F
>
> -----Original Message-----
> From: Jim Pruitt <jpruitt67@gmail.com>
> To: towertalk@contesting.com
> Sent: Mon, Aug 8, 2022 1:41 pm
> Subject: Re: [TowerTalk] ground plane problem help needed
>
> As near as I can tell these were not HyGain verticals. The mount part
> looks similar to them. No, there is no choke anywhere.there is just the
> black plastic insulator that the vertical part goes through at the top of
> the bracket and another at bottom where the SO239 is located.
>
> Thank you
> Jim Pruitt
> WA7DUY
>
> On Mon, Aug 8, 2022, 4:32 AM Jim W7RY <jimw7ry@gmail.com> wrote:
>
> > Is there a choke between the ground plane and the center conductor?
> > An ohm meter will confirm.
> > Hygain was famous for that.
> >
> > 73, Jim w7ry
> >
> > On Mon, Aug 8, 2022, 12:26 AM Jim Pruitt <jpruitt67@gmail.com> wrote:
> >
> >> About 4 years ago I picked up 2 bottom sections of what I think were 11
> >> meter ground planes. The section looks like the bottom section for a
> >> HyGain 18AVQ vertical or similar. The only difference is the mounting
> >> flange has a plate that holds what looks like about ½" diameter ground
> >> radials. The issue I am having is that I used that mounting section to
> >> make a 20 meter vertical. Easy enough, right? WRONG. I used mating
> >> tubes to make the ¼ wave 20 meter vertical but it resonated at...ready
> >> for this.... 39mhz! Then I grabbed the second one and used it. Now it
> >> resonates at 13.5mhz but shortening the vertical does not bring the
> >> frequency up. I am wondering if perhaps someone (CBer maybe) ran way
> >> too much power through them and broke down the dialectic of the plastic
> >> (or whatever that is) insulator that isolates the vertical from the
> >> mounting bracket and ground. That is the only explanation I can come up
> >> with as to why it is so far off.
> >>
> >> Does anyone have any suggestions as to how to fix the problem?
> >>
> >> Thank you.
> >>
> >> Jim Pruitt
> >> WA7DUY
> >> _______________________________________________
> >>
> >>
> >>
> >> _______________________________________________
> >> 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
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|