"Charging" system

[2RT307]

Thanks to Captain Kilowatt's post recently, I found myself perusing W8JI's web site and stumbled across this:

Antenna Grounds

The static comment is what really caught my attention, "Static drain chokes prevent electric fields from trickle charging a tower that has no resistive or DC path to earth. For example, my insulated 300-foot tower will charge to several thousand volts when brisk breezes flow, especially before storms. Walking up to the tower and touching it, on a day with a brisk breeze, produces quite a "wake-up shock"."

And then I started wondering... is there a way to harness this electricity generated by static? I know Ben Franklin did it! And if so, why don't commercial broadcasters use the energy to charge a battery system? Is it simply too much voltage to deal with? It seems like "free" electricity to me.

73,
RT307

 

[Robb]

What? You didn't ground your tower??? Man, are you going to have fun the next time a thunderstorm rolls by you!

Nyuk nyuk!

 

[Captain Kilowatt]

Thanks to Captain Kilowatt's post recently, I found myself perusing W8JI's web site and stumbled across this:

Antenna Grounds

The static comment is what really caught my attention, "Static drain chokes prevent electric fields from trickle charging a tower that has no resistive or DC path to earth. For example, my insulated 300-foot tower will charge to several thousand volts when brisk breezes flow, especially before storms. Walking up to the tower and touching it, on a day with a brisk breeze, produces quite a "wake-up shock"."

And then I started wondering... is there a way to harness this electricity generated by static? I know Ben Franklin did it! And if so, why don't commercial broadcasters use the energy to charge a battery system? Is it simply too much voltage to deal with? It seems like "free" electricity to me.

73,
RT307

Static buildup can be used to charge a capacitor but the real energy available over time is very small. Besides, how do you harness the static DC voltage from a tower that has thousands of watts of power being transmitter from it without detuning it from it's operating frequency? Answer: Very carefully. Besides that would require the tower to NOT be grounded which is a BIG no-no.

I remember one time when we were relocating an AM site due to urban growth. The new site was out in the wide open spaces and I was working on the ground system brazing the radials and ground screen under the 1450 KHz full sized quarter wave tower which was 160 feet tall and insulated from ground by a large ceramic base insulator. The static drain choke and static balls had not been installed yet and it was in the early days of December when the winds are cold and dry. After spending too much time on the ground I needed to stand up and stretch my legs. As I stood up I leaned against the tower. The next thing I knew I was back on the ground. I got one hell of a jolt but after the initial jolt it was all over and the tower began charging again. After that I went to the truck and grabbed the jumper cables and grounded the bastard until I hooked up the static drain choke and static balls.

 

[BJ radionut]

Static buildup can be used to charge a capacitor but the real energy available over time is very small. Besides, how do you harness the static DC voltage from a tower that has thousands of watts of power being transmitter from it without detuning it from it's operating frequency? Answer: Very carefully. Besides that would require the tower to NOT be grounded which is a BIG no-no.

I remember one time when we were relocating an AM site due to urban growth. The new site was out in the wide open spaces and I was working on the ground system brazing the radials and ground screen under the 1450 KHz full sized quarter wave tower which was 160 feet tall and insulated from ground by a large ceramic base insulator. The static drain choke and static balls had not been installed yet and it was in the early days of December when the winds are cold and dry. After spending too much time on the ground I needed to stand up and stretch my legs. As I stood up I leaned against the tower. The next thing I knew I was back on the ground. I got one hell of a jolt but after the initial jolt it was all over and the tower began charging again. After that I went to the truck and grabbed the jumper cables and grounded the bastard until I hooked up the static drain choke and static balls.

CK:...
Ah yes!...Jumping On and Off the tower...Gosh remember those days....
Had a couple small copper wrist straps with shorting jumpers(one on each arm)...clamp those off when working with the big leather gloves and rubber boots/leather Klein belt and pole strap....
To keep me SAME as the tower when changing those damn strobe lights!
73
All the Best
BJ

 

[2RT307]

Static buildup can be used to charge a capacitor but the real energy available over time is very small. Besides, how do you harness the static DC voltage from a tower that has thousands of watts of power being transmitter from it without detuning it from it's operating frequency? Answer: Very carefully. Besides that would require the tower to NOT be grounded which is a BIG no-no.

I remember one time when we were relocating an AM site due to urban growth. The new site was out in the wide open spaces and I was working on the ground system brazing the radials and ground screen under the 1450 KHz full sized quarter wave tower which was 160 feet tall and insulated from ground by a large ceramic base insulator. The static drain choke and static balls had not been installed yet and it was in the early days of December when the winds are cold and dry. After spending too much time on the ground I needed to stand up and stretch my legs. As I stood up I leaned against the tower. The next thing I knew I was back on the ground. I got one hell of a jolt but after the initial jolt it was all over and the tower began charging again. After that I went to the truck and grabbed the jumper cables and grounded the bastard until I hooked up the static drain choke and static balls.

Well, I was thinking of say, a TV tower, and some of those guys do shut down at night. What I did not think about was what you said, it is a short burst of high voltage. So, the power would not be something you could use for long periods of time.

Thanks for 'splainin'!

73,
RT307

 

[Captain Kilowatt]

Again it would have to be ungrounded which is bad business. The only towers that are not grounded directly are AM broadcast towers which sit on large base insulators.These towers have other means of grounding to prevent lightning damage such as drain chokes, static balls or spark gaps, as well as HEAVY components in the tuning components that are capable of taking lightning strikes and diverting a lot of the energy to ground. TV/FM/cellular towers etc, are all grounded directly for safety reasons.

 

[2RT307]

Again it would have to be ungrounded which is bad business. The only towers that are not grounded directly are AM broadcast towers which sit on large base insulators.These towers have other means of grounding to prevent lightning damage such as drain chokes, static balls or spark gaps, as well as HEAVY components in the tuning components that are capable of taking lightning strikes and diverting a lot of the energy to ground. TV/FM/cellular towers etc, are all grounded directly for safety reasons.

We had some equipment at my old job that used to generate huge amounts of static. It was supposed to be well grounded, but caused an arc between a guy and a roll of plastic that dropped him to the floor. Not pretty. Later found the grounds were less than ideal (duh) and had a static expert come in to fix all the issues we had. It made for a much happier place to work. No more zaps!

73,
RT307