Thanks Jim. I thought I had tower problems(or amps)!! better than delete
frac etc,etc.
73 Fred N3XBG FM19 50.125
On Mon, 4 Jan 1999 11:40:51 -1000 "Jim Reid" <jreid@aloha.net> writes:
>
>Aloha,
>
>Just finished a chat with the engineer in charge out at Manoa
>at WWVH. He is actually beginning planning for new antennas;
>was looking in the ARRL Antenna Book, how about that!
>
>Present verticals are Rohn towers, with center insulators!!
>Rohn evidently will no longer quote these for 1/2 wave vertical
>application. On site antennas were supplied and installed
>back in 1971, the year Kauai became the new home for
>the station which was moved from Maui. His notes, left
>by the engineer from some 27 years ago refer to the
>present set up as a "Franklin Design". Meant nothing
>to me.
>
>The engineer said he climbs the towers and Rohn is afraid of
>doing the center insulators, one on each of the three legs,
>as one or two are in compression while the third might be
>in tension. That is the part they are frightened about, hi.
>But the center insulators are, of course needed to form
>the two tower array of 1/2 wave antennas, one tower fed
>90 degrees out of phase with the other.
>
>I asked how high up the feed points were on 5, 10 and 15 MHz;
>he replied, as he recalled, at least 3/8ths wave, but seemed
>a little uncertain. The tallest tower is about 200 feet, but it
>is also a 1/2 wave vertical, center fed, for the 2.5MHz omni
>coverage, 5kW for local coverage here in Hawaii and the
>near by areas of the Pacific. 1/2 wave at 2.5 MHz is 196.6
>feet.
>
>He is quite concerned because of the lack of a source for
>new, center insulated towers. Said he had about decided
>to put out an RFQ for a professional engineer to come out
>to give him a hand in planning for a new antenna set up.
>Is quite concerned about radial needs if he is forced
>to go to 1/4 wave verticals. Does not want to loose
>field strength over in the Philippines, and other areas
>of the far Western Pacific. Would require a sea of
>radials beneath seven towers!
>
>His other problem is the transmitters; they are all by
>manufacturers' no longer in business: AELabs and
>AlcomPower, or some such. So is having to investigate
>that aspect of the station's upgrade also.
>
>Will be interesting to follow this project.
>
>So, that is the info about WWVH.
>
>73, Jim, KH7M
>On the Garden Island of Kauai
>
>
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>
>
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