Topband: Need antenna advice

[Mike Waters W0BTU]

Hello Guy,

Well, I'm quite happy with the inverted-L(/U) transmitting antenna now, after implementing the elevated radial changes you suggested. 

Just now, I worked my 13th country on 160 CW (Bulgaria, 5646 miles) in the short time I've had my transmitting antenna up. I heard him calling CQ on my Beverage (with no replies), but he was so weak I almost thought it was a waste of time to call him. He came back to me on my first call!

And I still only can run 100 watts. (Parts are ordered that will boost that to 700 watts).

This may very well be merely anecdotal evidence for the folded elevated radial change you suggested. But I'm certainly getting better results now that I implemented the change you suggested. It was so frustrating before; I made many, many calls, but no replies. I just couldn't figure out what in the world could be wrong. This is how I thought that the inverted-L should work at the power level I'm running. Thank you so much!

I've been listening on 160 with my Beverages for some time now on 160, and it has really been a lot of fun just listening. But it is that much much more fun now that I can transmit. I think I have the "160 disease". :-)

73,
Mike Waters
W0BTU


--- On Mon, 2/15/10, Guy Olinger K2AV <olinger at bellsouth.net> wrote:

> From: Guy Olinger K2AV <olinger at bellsouth.net>
> Subject: Re: Topband: Need antenna advice
> To: "Mike Waters W0BTU" <mrscience65704 at yahoo.com>, "J A Ritter" <jaritter at nc.rr.com>
> Date: Monday, February 15, 2010, 11:08 AM
> Hi Mike,
> 
> Thank you for the clarification.  I got a couple of
> similar
> clarifications from topband reflectorees. They understood
> right, so
> it's certainly no fault of yours. Senior moment...
> 
> I'm adding Jack Ritter, W0UCE, a local friend (here in
> Raleigh area)
> who has a pair of raised radials that are folded back to
> the center,
> used as a counter poise for a 134 foot L, with a tuned
> current block
> at the radial/vertical juncture.  Neither radials or
> vertical can
> "see" ground.  Folding them back lowered their
> radiation resistance as
> a dipole to five ohms. Using them as radials will lower
> radiation even
> further. The dimensions were something like 50' out 8 feet
> over and 50
> plus with miscellaneous routing of the ends.  The
> radial length was
> used to tune the overall system, not achieve radial
> self-resonance.
> Quit a different animal when the radials are folded back
> on
> themselves.
> 
> We used PVC insulated #12 from the Home Depot, leaving the
> insulation
> ON.  This increases the electrical length of the
> wire.
> 
> I'm hoping that Jack can schedule you for a demonstration
> of his
> antenna, with both 100 watts and QRO.  If you're in
> agreement, please
> give Jack a phone number.  I'm calling in a favor and
> passing it
> forward, so to speak.
> 
> 
> A couple of conclusions from some research around here:
> 
> 1) two radials cannot be a significant shield for
> induced-current-in-ground types of losses, so anything that
> diminishes
> radials actually radiating or coupling to the ground will
> be helpful.
> 
> 2) any current on the feedline back to shack or to a ground
> rod is a
> waste, so an effective current block at the juncture of
> radials and
> juncture is a must. One must force any loss to be those
> inherent to
> the radials themselves or the vertical.
> 
> This is a good time to master what you have.  You can
> add your
> experience to our research.
> 
> 73, Guy.
[snip]
> > Mine was modeled after K3LR's design at
> > http://lists.contesting.com/_topband/2006-12/msg00161.html.
> The two elevated radials are 10' off the ground.
> >
> > I never thought of "treat[ing] the two radials like a
> dipole and see[ing] where they resonate. Adjust the length
> to resonate on 160". Great advice!
> >
> > If the weather would have been different, I would not
> have used two elevated radials. But laying down 60+ radials
> was simply not possible until the ground dries out and we
> can cut down the thorns and the heavy tangled pasture grass.
> By the time I can do that, the QRN level will be higher.
> This was my only option for now, at least that I could think
> of. I guess I should have stated that. Hey, it was a great
> learning experience.
> >
> > Thanks again.
> >
> > 73,
> > Mike Waters
> > W0BTU
> >
> >
> > --- On Fri, 2/12/10, Guy Olinger K2AV <olinger at bellsouth.net>
> wrote:
> >
[snip]
> >> Do something more permanent and reliable in the
> spring.
> >>
> >> 73, Guy.
> >>
> >> On Thu, Feb 11, 2010 at 11:07 PM, Mike Waters
> W0BTU
> >> <mrscience65704 at yahoo.com>
> >> wrote:
> >> > Ok, I feel a little foolish asking this
> question, but
> >> I wonder if anyone on the Topband list can offer
> some
> >> suggestions as to why my transmitted signal on 160
> might be
> >> so weak.
> >> >
> >> > I can hear very, VERY well on 160. I am in a
> very
> >> quiet location, and I have two 2-wire bi-direction
> Beverages
> >> which hear VERY well. I've been playing with
> receiving
> >> antennas on 160 for a long time, and I decided it
> was
> >> finally time to see what I could accomplish on
> 160. But
> >> after finally erecting a transmitting antenna, my
> signal on
> >> 160 is very weak to every person I've ever tried
> to work. DX
> >> and stateside, CW and SSB. I put up the best xmit
> antenna
> >> that was possible at this time of year, just
> before the CQ
> >> 160 contest.
> >> >
> >> > I can only run 100 watts at this time.
> >> >
> >> > I tried the inverted-U antenna as described
> in the
> >> links below. It is very similar to the one that
> K3LR used in
> >> the first link. The antenna is over the top of a
> 60' oak
> >> tree, and the two elevated radials are about 10'
> high.
> >> >
> >> > I'd put down a lot of radials and a
> top-loaded T
> >> antenna, but that's just not possible with the
> weather this
> >> time of year.
> >> >
> >> > Am I expecting too much with just 100 watts?
> I don't
> >> think so; I've heard of many hams working DXCC
> without an
> >> amplifier. It was my intention to get a
> transmitting antenna
> >> working well at the 100 watt level, and then
> building a
> >> legal limit amplifier.
> >> >
> >> >
> >> > I've operated 3.5 through 144 MHz since 1976,
> but this
> >> is the worst experience I have ever had since I've
> been
> >> licensed. I know this is almost a stupid question,
> but I
> >> have to ask it before I go crazy.
> >> >
> >> > Thanks in advance for your patience,
> gentlemen. :-)
> >> >
> >> > 73,
> >> > Mike Waters
> >> > W0BTU