I think both Gary and Forrest are correct. Now that I think a bit more
clearly, someone told me that the top of our spire is ~150 ft and the new
tower to our south is 200 ft. Still, 150 ft ain't too shabby.
I also failed to mention that the CEO of DX Engineering, Tim Duffy K3LR,
made us a special price for the new antenna. He lived in Edmond for a few
years while working for a cell company and suffered a close encounter of
the Tornadic kind. He naturally became interested in severe weather and, a
few years ago, I gave both him and his son and special VIP tour of the NWC.
Tim was impressed and grateful to us for the tour. He later gave a
marvelous talk about his world-class contest station to the OUARC and later
was very generous to the Oklahoma DX Association. I contacted him about
this new antennas, and nice deal ensued.
In the next few days, I'm going to send him a picture of the antenna on the
NWC and thank him again for his help.
73,
Kim N5OP
On Wed, Jun 6, 2018 at 9:59 PM, Forrest Mitchell - NOAA Federal <
[log in to unmask]> wrote:
> I believe the new tower to the SW of the NWC is a 200 footer, hence the
> light on top. It is, indeed, taller than the top of the NWC tower, as
> viewed from a distance, so we are still within guidelines.
>
> Forrest Mitchell / KB5FOL
> *Observations Program Leader*
>
> NOAA/National Weather Service
> Oklahoma City / Norman Weather Forecast Office
> 120 David L Boren Blvd, Suite 2400
> <https://maps.google.com/?q=120+David+L+Boren+Blvd,+Suite+2400+Norman,+OK+73072+405&entry=gmail&source=g>
> Norman, OK 73072
> <https://maps.google.com/?q=120+David+L+Boren+Blvd,+Suite+2400+Norman,+OK+73072+405&entry=gmail&source=g>
> 405
> <https://maps.google.com/?q=120+David+L+Boren+Blvd,+Suite+2400+Norman,+OK+73072+405&entry=gmail&source=g>
> -325-3816
>
> On Wed, Jun 6, 2018 at 9:47 PM, Gary Skaggs <[log in to unmask]> wrote:
>
>> Kim,
>>
>> Thanks for the blow-by-blow.
>>
>> I will say, however, that IMO the antenna sits at 190 feet. Any higher,
>> and it should be lighted. I'll stick with the 190 number until someone
>> determines "official ground level" of the antenna structure, and then
>> measures it with steel tape. Anything else is mere speculation, AFAIAC.
>>
>> Good DX to all, and to all a good night.
>>
>> Gary
>>
>>
>> On Wed, Jun 6, 2018 at 4:56 PM, Kim Elmore <[log in to unmask]> wrote:
>>
>>> The new HF antenna atop the NWC is now installed! Installation was
>>> handled by Top Hand Tower, the same company that installed the SteppIR some
>>> years ago.
>>>
>>> We took precautions during the building and installation to insure that
>>> we won;t have to do this again for a long, long time. The antenna itself is
>>> a DXEngineering Skyhawk 3X10 antenna, with 4 elements on 10 m, and three
>>> each on 15 m and 20 m. Each element is riveted together, so there are no
>>> hose clamps to fail. Each element has a short length of sash cord in each
>>> end secured with urethane glue; these act to dampen any vibrations in the
>>> elements that may be excited by the wind. Every piece of threaded hardware
>>> is secured by medium strength (blue) thread locker, including the clamps on
>>> the rotator. The rotator mast clamp bolts had come loose due to vibration;
>>> they will not do so now with the thread locker. The rotator had a new Grade
>>> 8 mast pin installed because the loose mast clamp hardware allowed enough
>>> play for the SteppIR antenna to break the old mast pin.
>>>
>>> The antenna is an OWA (Optimized Wide-band Antenna) yagi design that
>>> should be relatively flat across all three bands. With an auto tuner, it
>>> can be used as a non-directional antenna on 17 m and 12 m and possibly 30
>>> m. It has been tested and, using the reflectometer indication on the
>>> IC-7000 radio we have in the station, the match is good across all of 10 m
>>> and 15 m, but the SWR runs a bit high on 20 m with about 1.5:1 on 14 MHz
>>> and 2.5:1 at 14.35 MHz. Given that the match is good on 10 and 15, the
>>> antenna is assembled correctly. It would be very difficult to assemble it
>>> incorrectly due to its construction, but I suppose it could be done with
>>> enough ingenuity. I, along with Jorge Duartes, W5/HJ3JDG, assembled the
>>> antenna and neither of us are quite ingenuous enough to figure out how to
>>> screw it up. The reflectometers in HF radios are notoriously inaccurate
>>> (the one in my TenTec Orion II isn't very good, either, though the one in
>>> my venerable TS-930S is quite accurate) and I suspect that is the case
>>> here: the antenna is likely better than it looks via the display on 20 m
>>> though the IC-7000 display. However, the club owns an auto tuner that is...
>>> Somewhere. We will find it, install it, and worry no more about such
>>> issues.
>>>
>>> It's important to recognize that this station would not exist without
>>> Doug Forsyth's (WX5DF) foresight, technical support from Ken Brown, N5KUK,
>>> support from the University of Oklahoma, and support form the National
>>> Severe Storms Laboratory. An antenna of this quality, up 200 ft, driven by
>>> a rig as capable is the IC-7000 is an unusually good asset for any club
>>> station and a rare treat for anyone interested in HF operating.
>>>
>>> Now, go get on the air!
>>>
>>> 73,
>>>
>>> Kim Elmore N5OP
>>> OUARC Faculty Advisor
>>> --
>>>
>>> Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP
>>> SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)
>>>
>>> *“The weather is never wrong.” – Pam Wilson*
>>>
>>
>>
>
--
Kim Elmore, Ph.D. (Adj. Assoc. Prof., OU School of Meteorology, CCM, PP
SEL/MEL/Glider, UAS, N5OP, 2nd Class Radiotelegraph, GROL)
*“The weather is never wrong.” – Pam Wilson*
|
