Topband: 30-Foot Vertical
k8gg at voyager.net
k8gg at voyager.net
Tue Jun 4 17:18:40 EDT 2019
I agree with Dave, If one can get 20 feet of mast out the top of the 30
foot tower and some top loading wires to bring resonance to where one
desires in the 160 meter band then I would insulate the base and series
It would be only about 3 db below a full size vertical over the same
radial system and earth ground below.
Feed point impedance will be between 12 and 25 ohms depending on ground
losses, assuming at least 2000 feet of radials on ground, or decent
elevated radials on a roof.
GL 73, George, K8GG
> During my 1988-1989 stint as J52US in Guinea-Bissau and 1990-1991 stay
> as 9L1US, I made loads of QSO's in pile-ups and contests with a modified
> Butternut HF-2V.?? I bought larger tubing for the top section and moved
> the top-loading wires higher.?? The antenna then worked well on 160 and
> 80 and was not resonant on 40m.?? In both places the antenna was high--on
> top of a five story building with radials running on the roof and
> running down several stories to warehouse roof in Guinea-Bissau and on
> the flat roof of a three story apartment building atop one of the
> highest hills overlooking Freetown in Sierra Leone.?? In both places I
> had a tri-bander on several sections of tower on the roofs as well.
> I made contacts from Helsinki in the mid-1980's with the same antenna
> (stock) but without as much success and again in the mid-1990's with it
> modified per the African variant but on the roof of a two-story building.
> You might do pretty well with some top-loading wires and perhaps you
> could use a mast to give it a little more height.
> Dave K8MN
> On 04-Jun-19 19:14, Mark - N5OT wrote:
>> Hi Roy - you mean for 160 meters??? I think there are plenty of
>> credible ways to cobble odd pieces of tower together to make a useful
>> antenna, especially if climbing it is never something you need to do,
>> and if it crashed to the ground it's not that big a deal.
>> If you're asking if a 30 foot vertical can be made to be useful on 160
>> meters, I think, depending on the definition of "useful" the answer
>> can definitely be YES and I can think of a whole lot of QSOs that have
>> been made with verticals about that tall.
>> 73 - Mark N5OT
>> On 6/4/2019 8:41 AM, Roy Morgan wrote:
>>> Hello Topbanders,
>>> I have three 10-fot sections of triangular steel tower, about 8
>>> inches on a side.
>>> Is it practical for me to make a useful vertical with these, either
>>> bottom fed or gamma matched?
>>> Thanks for advice or experience.
>>> Roy Morgan
>>> K1LKY since 1958
>>> k1lky68 at gmail.com
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