your HF antenna ... insulated backstay, other ?
 

Don White wrote in news:ZKg0g.60624$VV4.1122705
@ursa-nb00s0.nbnet.nb.ca:

2000 feet??
That would be higher than the worlds tallest free standing
structure...the CN Tower in Toronto.
http://www.cntower.ca/portal/
Do they hang their antenna from a 'sky hook'?



Ok, you got me. Their antenna isn't at the top of the tower the 3
stations are on:

WTAT-TV SC CHARLESTON USA

Licensee: WTAT LICENSEE, LLC
Service Designation: TV NTSC (analog) television station
Channel: 24 530 - 536 MHz Licensed
File No.: BLCT-19900418KE Facility ID number: 416
CDBS Application ID No.: 147538

32° 56' 24.00" N Latitude

79° 41' 45.00" W Longitude (NAD 27)

Polarization: Horizontal (H)
Effective Radiated Power (ERP): 5000. kW ERP
Antenna Height Above Average Terrain: 542. meters HAAT
Antenna Height Above Mean Sea Level: 544. meters AMSL
Antenna Height Above Ground Level: 539. meters AGL

TV Zone: 2
Frequency Offset: 0 (zero)


Directional Antenna ID No.: 18713 Pattern Rotation:
0.00
Antenna Make: DIE Antenna Model: ODD900418KE

Relative Field values for directional antenna Relative Field
polar plot
Relative field values do not include any pattern rotation that may be
indicated above.

0° 0.915 60° 0.632 120° 0.403 180° 0.317
240° 0.825 300° 0.988
10° 0.885 70° 0.522 130° 0.443 190° 0.407
250° 0.858 310° 0.999
20° 0.858 80° 0.407 140° 0.443 200° 0.522
260° 0.886 320° 0.999
30° 0.825 90° 0.317 150° 0.403 210° 0.632
270° 0.915 330° 0.988
40° 0.782 100° 0.296 160° 0.342 220° 0.718
280° 0.943 340° 0.968
50° 0.718 110° 0.342 170° 0.296 230° 0.782
290° 0.968 350° 0.943

And, they're only running a mere 5000 KW ERP, still the most powerful UHF
station in SC. The collector voltage on the big klystrons is 25KV.

WCSC-TV5 is the top antenna:

WCSC-TV SC CHARLESTON USA

Licensee: WCSC, INC.
Service Designation: TV NTSC (analog) television station
Channel: 5 76 - 82 MHz Licensed
File No.: BMLCT-20050628AAY Facility ID number: 71297
CDBS Application ID No.: 1068924

32° 55' 28.00" N Latitude

79° 41' 58.00" W Longitude (NAD 27)

Polarization: Horizontal (H)
Effective Radiated Power (ERP): 100. kW ERP
Antenna Height Above Average Terrain: 596. meters HAAT
Antenna Height Above Mean Sea Level: 599.9 meters AMSL
Antenna Height Above Ground Level: 595. meters AGL

They're at 600 meters. Between Channel 4 and 5's antennas is a work
platform. On that platform is one of our 2 meter ham repeaters on
147.300 Mhz. 100 miles in this flat country is easy with 50 watts...(c;

The towers are right along the ICW in Awendaw, SC, just north of Mt
Pleasant. There were 3 towers until Channel 24's monster fell feet from
a lady's house in Hurricane Hugo. She reported it made a loud noise....

The elevator ride up to the repeater makes it feel like 10,000 ft. You
can't see your car in the parking lot and the tower appears to disappear
to a point below you. Clouds pass through you or below you, a very eerie
feeling. The view out to sea from the platform is simply beautiful. How
the tower and repeater survive our big thunderstorms is amazing.

But, alas, we digress off topic....(c;
Dead Wreckoners have no trouble N of Charleston getting a bearing on
them, even at night when their very high intensity strobes clearly mark
their presence.

your HF antenna ... insulated backstay, other ?
 

I use an insulated backstay. It's a bit tricky because the main
backstay is split about 20' above the deck, like a big inverted Y. I
ended up using three insulators, 1 at the top of the backstay about 6'
short of the mast, one at the Y to isolate 1 leg, and another at the
base of the other leg of the Y above the deck. The whole thing is like
an inverted Y with one leg of the V portion cut off. (Hope that makes
sense.)

The rig itself is an ICOM 706 MkII with their AH-1 random wire antenna
tuner. I have a dynaplate on the outside of the hull that forms part of
the ground system, and the enclosed lead keel acts as a counterpoise.

I've had excellent success with this setup, and so far no maintenance at
all (only been a year). Even with the sunspot cycle at its low point
I've made contacts throughout Europe and Russia, Africa, etc.

purple_stars wrote:
for those who use HF on their boat, i'm curious what antenna choices
you have made. did you go with an insulated backstay or something else
entirely ? how do you have it all set up on your boat ? i've read
that some people just hoist a wire up with some line and hook it to
their antenna tuner (with a ground of course). are you doing anything
more or less fancy ? if you're using an insulated backstay do you
trust the insulators to keep the mast up ? how much maintenance is
involved in your HF antenna setup ? i'm just curious in general what
solutions people have found since i'm researching it now.

thanks in advance.