Maybe someone out there with ant modeling software
can help me with this question. Question is, how much
tubing would need to be added to the tower decsribed
below, to make it resonant at 1.830 mhz ?
BASIC STARTING POINT
Rohn 25 on a insulated base going up to a height of 112
feet & the top of the tower (proper) is a Rohn "pointy"
top section. So, from the top of the "pointy" top to to
the insulated base = 112 feet of continious metal.
Now, this is whats planned to extend upwards from
the "pointy top" & these are all usable lengths (over lap)
has been accounted for.
11 ft of 2 inch O.D. tubing ( this is a 12 ft pc of 2" OD with the 1st
ft
of it mounted along side the
"pointy top"
tubing with 2 "mast to mast"
clamps.)
5 ft 6 inches of 1 7/8 inch O.D. tubing
5 ft 6 inches of 1 3/4 inch O.D. tubing
So, now we have 134 feet of usable vertical metal
with the above described taper. Again question is
how much tubing need be added to resonate at 1.83 mhz ?
Please use the following tube sizes & "usable lengths"
for the additional tubing.
5 ft 6 inches of 1 5/8 in O.D. (if more needed) go to
5 ft 6 inches of 1 1/2 in O.D (if more GEZZZZ i hpe not) use
5 ft 6 inches of 1 3/8 in O.D. stop..
I realize, that we reach a point where the spegettii sticking
out of the top will no longer support itself & if thats the
case maybe one more section of rohn 25 or a larger sized
"starting point" tubing or more extreme tubing size reduction
may work better. I think it will work as described if no more than
2 additional pcs of tubing are needed.
There will be "guy points" at the following heights 25', 54', 83',
& 109 ft The guys will be "non metallic" but the first 3 feet
of each guy as it leaves the tower will be metallic. All guys will
attach to anchors located 71 ft out from the tower.
I started not to include the following info with my question as i
did not think it would have any bearing on the "answer" but i'll
throw it in also.
The "base" of this tower will be 35 ft above the ground.
The 1st 35 ft will also be rohn 25 but there will be a insulated
joint at 35 ft and the actual antenna will start at that point &
be as i described above. there will b 4 qtr wave radials just
above the insulated joint. There will be continious metallic
guys at the 30 ft point on this 35 ft pc of tower also attached
to the anchors located 71ft from the tower. The reason for
the high "starting point" for this ant is to overcome severe
sloping ground and to make the ant base level with the 3 other
towers to be added later.
I realize we can find the resonant point at 1.83 mhz by measuring
& adding/subtracting tubing then measuring again but sure wud be
nice to initially just have to maybe reduce the length of the tubing
a few inches then measure agn es be done. By the way this is
not my system but is a friend who does not have e-mail.
Tnx Ed KG4W
NNNN
.
>From Ka9a@cris.com (Bill Fageol) Thu Jun 20 17:30:08 1996
From: Ka9a@cris.com (Bill Fageol) (Bill Fageol)
Subject: All this KV4 stuff
Message-ID: <Pine.SUN.3.93.960620122225.4464A-100000@viking.cris.com>
On Tue, 18 Jun 1996, Charles H. Harpole wrote:
> Is it possible to say any more about the KV4 call sign???
> BTW, I want the call KV4UD !!! de K4VUD
>
>
Speaking of KV4 calls, does anyone have a qsl for KV4CX in the early
sixties?? Looking for a nice photo copy of a qsl with my first call.
Thanks, Bill ex-KV4CX, ex-DL4IA
and more.... ka9a@cris.com
>From jdcolson@aplcomm.jhuapl.edu (Jack D.Colson) Thu Jun 20 17:34:37 1996
From: jdcolson@aplcomm.jhuapl.edu (Jack D.Colson) (Jack D.Colson)
Subject: SS Reports - W4KFC?
Message-ID: <9606201634.AA25245@aplcomm.jhuapl.edu>
Another favorite story about W4KFC is: We just put up his 3 el 20 meter beam
and he gets on 20 CW to check it out and is called by some Russian. The Russian
insists that Vic QSY to 14250 to check his signal for an AM phone QSO. Vic
tells him repeatidly, NO PHONE! Vic did not own a mic. The Russian kept asking
so Vic QSy'ed to 14250 and held the key down and beat on his homebrewq VFO
which sat on a large piece of foam to isolate it from room vibrations. The
Russian came back and said QRM, QRM try again. So then more beating on the
VFO and the Russian replied, solid copy OM, 59 and tks QSO! I would like to
have seen that QSL.
I'm sure there are more but that is enuf for now!
73
W3TMZ
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