[NLRS] 160 meter vertical

[Clare Jarvis]

Dave,

I have done quite a bit of modeling on 160M and I don't think you
can put out much of a signal with a ten foot antenna, no matter how
you load it.   The other problem is without radials, verticals do not
radiate, because you only have half an antennae.  

Clare   K0NY






On Wednesday 12 November 2003 05:15 am, Dave Aho wrote:
> I know that this is HF and not NLRS related per se,
> but If any of you have done any HF work in this area,
> please let me know and give me some ideas.
>
> Well, I have a few thoughts rolling in my head to get
> done by the 160 meter contest...any hints would be
> appreciated.
>
>   Remember I am in a trailer court...the antenna is to
> be mounted on a tilt up tower unit on a utility
> trailer  I really have no way of running a bunch of
> ground radials out at the base or even a long
> counterpoise...I might, but I have to worry about the
> somewhat rare but present little kids running through
> the yard down here....they don't believe in following
> the caution tape...they just ignore it all...anyhoo
> here is my plan as follows:
>
>   tower is 2 sections of rohn 20/25...I will have
> masting pipe on top of that by about 8-10 feet (maybe
> more)...attached to this masting is going to be the
> mounting clamp for the antenna (ground side connected
> to tower).  THe antenna as I visualize it is going to
> be PL-259 fed at the bottom of a loading coil (3.5 to
> 4.5 inches diameter of either PVC or Carboard tubing
> of a to be determined length) to be wound to produce
> the end result of a 5/8 wave antenna overall length.
> I am thinking af AWG12 or 14 wire for the
> windings...does it have to be bare wire, or can it be
> insulated? On top of the loading coil is going to be a
> 3/8-24 threaded nut so I can put a 102" whip (either
> fiberglass which I have a few of, or Stainless which I
> need to buy...or an equivalent 10/11 meter 1/4 wave or
> longer mobile whip.)  I could also thread on my 40
> meter coil/whip for the Valor AB-5 mobile antenna if I
> wish I suppose, but I am thinking not.  I know this is
> going to be a marginal antenna...being physically
> short, but I am making it electrically 5/8 wave...or
> 1/2 wave if that would work better for multiband
> work..(as in 80 and 40 meters) as I  notice at least
> with 2 meter and 10 meter that the gain is
> considerabley more even with loading coils over the
> 1/4 wave antennas.
>
>    Please let me know...I am trying to be as simple as
> possible, with no extraneous other coils, matching
> networks, ground radials and such as it is to be used
> as a mobile antenna also (under the 13'6" rule) if I
> wish.  I will also add that I do have a 160 meter
> capable tuner for the shack also...so the match does
> not have to be super perfect...and bandwidth is not
> really an issue as I am used to returning per freq.  I
> am maybe going to make the prototype this weekend to
> get on the lower bands for SS, so hopefully you can
> feed me info by then.  Thanks all.
>
>
>
> =====
> 73, and all that jazz,
>
>
>                  Dave...N9TTX
>
>
> Always remember:  "It could be worse.....it could be raining."
>                              Marty Feldman from "Young Frankenstein"
>
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