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Lightning protection
- Thread starter fisjr
- Start date
I think putting the coax end into a malt Liquor bottle would be much safer. If it could stand up to holding malt liquor then lightning won't be much of a problem.
pretty much the same SPG (single point grounding).
Each of the standards refers to the concept of single-point grounding (SPG), which is absolutely essential
Grounding standards for broadcast check out the lightning strike pic,......... WOW!!!
Everything is all connected to one common point called station ground. All cables such as power,phone, coax etc, should come through the same hole or at least at the same point in the building as well with large toroid installed over them. Coax cables are grounded inside and outside the buildings in FM sites and the AM sites have the ground radials bonded to the main station ground as well. Not unusual to see long runs of heavy copper strap as wide as six inches in a lot of sites to bond transmitter cabinets and equipment racks etc. to the main ground buss that usually runs along the floor and is of the same heavy copper strap.
for a better desing and system it is good practice to bring all the groun to one point. that is why i don't thing it is necessary to do this and i don't thiknk it will do much help for lightning protection.
I've seen many terrible broadcast installations in terms of grounding. You can't always look at those people and assume they know what they are doing. Typically, quite the opposite is true. Get some guy out of tech school, he's never seen a radio transmitter, no idea about RF, and suddenly he's the station chief engineer.
A typical radio station, whether commercial broadcast, VHF communications company, cell phone, or amateur will have two ground systems. One is provided by the AC power company. There will be a ground rod at the AC entrance panel and all equipment will tie to it. The second is created by the tower, guy anchor points, radials, etc. The two ground systems will be at different potentials, and current will flow between them. The trick is to ensure this current does not flow through any equipment. The RF entrance and AC entrance should be as close as possible and bonded together. RF lines entering the building should be bonded to the AC/RF ground and toroid chokes placed over them to reduce common mode current. Phone lines should enter at the same point as well and have toroids before distributing through the building.
I've compiled my notes on grounding and other broadcast topics and posted on my personal web page. There are links to documents from manufacturers (Nautel and Broadcast Electronics) as well as Polyphaser. Read through and get into the mindset of what is being said. Properly installed, there should be little concern for ground issues and a station can continue operating throughout a lightning storm without worry. It's the improper installations that get blown to pieces.
http://members.rennlist.org/warren/grounding.pdf
A typical radio station, whether commercial broadcast, VHF communications company, cell phone, or amateur will have two ground systems. One is provided by the AC power company. There will be a ground rod at the AC entrance panel and all equipment will tie to it. The second is created by the tower, guy anchor points, radials, etc. The two ground systems will be at different potentials, and current will flow between them. The trick is to ensure this current does not flow through any equipment. The RF entrance and AC entrance should be as close as possible and bonded together. RF lines entering the building should be bonded to the AC/RF ground and toroid chokes placed over them to reduce common mode current. Phone lines should enter at the same point as well and have toroids before distributing through the building.
I've compiled my notes on grounding and other broadcast topics and posted on my personal web page. There are links to documents from manufacturers (Nautel and Broadcast Electronics) as well as Polyphaser. Read through and get into the mindset of what is being said. Properly installed, there should be little concern for ground issues and a station can continue operating throughout a lightning storm without worry. It's the improper installations that get blown to pieces.
http://members.rennlist.org/warren/grounding.pdf