Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
"Jack Painter" wrote in
news:xLD8e.2235$lz1.1261@lakeread01: I have been perusing the information on Lightning Protection in the link that you provided. As a side issue, have you studied CAT III Voltmeter protection? http://www.ecmweb.com/mag/electric_m...afety_measure/ Also, being too tired to digest much more information, and having saved the information from your posts, have you ever see this antenna, any comments that you have would be appreciated? http://www.universal-radio.com/catal...wire/4075.html As usual, reading the reviews on EHAM, several were positive, a couple were absolutely negative. It's an end fed antenna that they represent as needing a 25 foot central rise. The reviews seem to talk about counterpoise, though the drawing at the link above seems to be suggesting that the central pillar is the counterpoise, I would guess that it is a network of wires needed to be buried. The 2 legs are 55 feet, to the rise that is, and one of the reviews complained that the actual overall length was longer than advertised. "Also they're saying it only takes 88 feet of space is flat out wrong. If you do simple math it will tell you 97 feet with the 25 foot support. I put mine up to 30 feet and it takes up 92 feet overall." Lastly, I would guess that people should not be exposed to the antenna when transmitting. Alas this would still put me back into the need of a vertical antenna for transmitting with sufficient rise above the yard for safety. http://www.eham.net/reviews/detail/1550 Nevertheless, I am still seeking to improve my receiving antenna for SWL with the addition of lightning protection. Thanks again, Dr. Artaud |
#2
![]() |
|||
|
|||
![]()
About five years or more ago,I was checking out www.lightningstorm.com
and one of the links in that website was about two or three models of electronic advanced lightning warning devices.I think one of the lnks said the devices can give about one minute of advanced lightning strike warning.I guess a search on the internet might turn up some information about those devices.I think I remember they are pretty pricey though.Unless the prices on them have come down. cuhulin |
#3
![]() |
|||
|
|||
![]() "§ Dr. Artaud §" wrote I have been perusing the information on Lightning Protection in the link that you provided. As a side issue, have you studied CAT III Voltmeter protection? http://www.ecmweb.com/mag/electric_m...afety_measure/ Arc-flash and arc-blast prevention/safety measure rules have been a big focus of training programs lately. Guards were installed around many equipments that have the capabiity to generate arcing, and you can't walk near HV equipment areas without face shield, etc now. I personally have an old Beckman Industrial 320B digital multimeter which only has the safety of it's operator's care behind it ;-) For my use at 240v or less at home that's fine for me. Also, being too tired to digest much more information, and having saved the information from your posts, have you ever see this antenna, any comments that you have would be appreciated? http://www.universal-radio.com/catal...wire/4075.html As usual, reading the reviews on EHAM, several were positive, a couple were absolutely negative. It's an end fed antenna that they represent as needing a 25 foot central rise. The reviews seem to talk about counterpoise, though the drawing at the link above seems to be suggesting that the central pillar is the counterpoise, I would guess that it is a network of wires needed to be buried. The 2 legs are 55 feet, to the rise that is, and one of the reviews complained that the actual overall length was longer than advertised. "Also they're saying it only takes 88 feet of space is flat out wrong. If you do simple math it will tell you 97 feet with the 25 foot support. I put mine up to 30 feet and it takes up 92 feet overall." Lastly, I would guess that people should not be exposed to the antenna when transmitting. Alas this would still put me back into the need of a vertical antenna for transmitting with sufficient rise above the yard for safety. http://www.eham.net/reviews/detail/1550 Nevertheless, I am still seeking to improve my receiving antenna for SWL with the addition of lightning protection. Thanks again, Dr. Artaud As long as a 100-200w ERP antenna is not within about 10 feet of where people can linger, and it will not be touched, you should be fine. I had to run a safety data sheet for a 1kw, and post signs in case some numbskull climbs over my yard fence, but there was no personnel hazard from radiation beyond 10' of the antennas. The feedpoint on an end-fed antenna has dangerous voltages present during transmitting. Making sure no person or animal comes near that during transmitting is your responsibility. B&W has a reputation for some pretty good but pretty expensive antennas. Realize that their antenna seem to favor Automatic Link Establishment (ALE) systems. The military equivalents B&W are copying are all Near Vertical Incident Skywave (NVIS) antennas. Also known as "cloud-warmers" because they shower radiation down over a 200 mile area from launching nearly straight up. So B&W's claims of low radiation angles in the lower bands sounds like a contradiction, especially from such a short antenna for 160 meters. Possibly eats 80% of the power input but after all, some hams do that from their cars on 160m. If you can afford the experiment, that B&W might be just the ticket, and it probably works fairly well where your current license can take you. Write me off-line when you get ready to tie some coax shield grounding and station ground rods together, I'll be glad to help. best regards, Jack |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
NEC Section 810 Online? | Antenna | |||
Single ground | Antenna | |||
Lightning Strikes Boat Anchor | Boatanchors | |||
Balun Grounding Question ? | Shortwave | |||
Antenna mount | Scanner |