GROUNDING AN A99

[Stellasarat]

Captain kilowatt posted an excellent site for grounding all types of antennas. It suggests that you use 26)awg attached to a five to eight ft copper steak. Is this totally necessary? I know it's a very good idea to ground you antenna but 5-8 ft seems a bit deep. I may put up an a 99. Would it be sufficient enough to go about 2-3 ft down into the earth? The ground it will be going onto is moist grass covered. During the summer months the grass is automaticly watered atleast once ever two days. I don't know if the earth being moist makes a difference but it's impossible to drive a steak 5-8 ft into the earth. What's the least amount of depth I can go and still feel safe from a lightning strike to an a99 or any omnidirectional antenna for that matter. Are there any at alternative grounding options?

 

[hotrod]

Captain kilowatt posted an excellent site for grounding all types of antennas. It suggests that you use 26)awg attached to a five to eight ft copper steak. Is this totally necessary? I know it's a very good idea to ground you antenna but 5-8 ft seems a bit deep. I may put up an a 99. Would it be sufficient enough to go about 2-3 ft down into the earth? The ground it will be going onto is moist grass covered. During the summer months the grass is automaticly watered atleast once ever two days. I don't know if the earth being moist makes a difference but it's impossible to drive a steak 5-8 ft into the earth. What's the least amount of depth I can go and still feel safe from a lightning strike to an a99 or any omnidirectional antenna for that matter. Are there any at alternative grounding options?

no you want a 8 ft ground rod. you can pound it in ground.i dug a smal hole to get started
then pound.also dont hook it to the c -clamps at bottom of antenna .[ive done that]
attatch the wire to the mast/tower near the ground rod. my copper braid was around 1 inch
and bolted to mast. wire starts to act as a antenna near 9 feet

 

[loosecannon]

its all about how much earth your ground rod comes into contact with.

if you are not going to go a full 8 feet into the ground with your ground rods, then you need more than one. about 4 should do you nicely if they are going into the ground about 4 feet. (you should not have more than a few inches above the ground)

is it necessary?
well, that can be a tough question to answer. 4 ground rods are not going to stop a lightning strike, and if your antenna does actually take a direct hit, its still going to explode in a spectacular fashion, its still going to send a hell of a lot of current down your coax towards your shack, and its still going to (hopefully) pop the main breaker in your house.

im sure anyone that has actually had lightning hit their antenna feels very strongly about proper grounding, and if you look at the articles online, they make you feel like if you dont spend 5,000 dollars on a grounding setup that you are in great danger.
however, the majority of CB stations have minimal grounding setups and live their entire lives in relative uneventfulness.

if it were my station, i would have a ground rod or two right outside the shack that are tied to the main AC mains ground.
i would mount a "real" lightning arrestor (you're going to pay 60+ dollars for it) to that ground rod.
i would run the coax from the antenna to that arrestor, and then out of the arrestor into the shack.
then i would mount a grounding panel on the wall behind the station desk, and tie it to the ground rod also using less than 8 feet of wire to do it.
then i would run a grounding strap from each piece of equipment to the grounding panel.

am i perfectly protected against any danger of fire in the case of a lightning strike?
well, probably not.
but, the current from the strike has to travel down my coax, burning it up in the process, then go through the lighthing arrestor, probably blasting it too, and then into the shack.

thats just me, and its not a cure all for all stations, but hopefully it gives you some perspective.
LC

 

[W5LZ]

Oh lord, this is one'a them things that get misunderstood real quickly. 'Grounding an antenna for possible lightning thingys is so miss understood that it's almost impossible to correct without a big number of steps backwards.
There is a huge difference between an RF ground and a Safety ground. One makes the antenna work 'right', the other keeps your antenna system from being toatally destroyd by lightning. That 'totally destroyed' thingy is a lie to start with, it only provides some protection, not an absolute thingy at all. If you ever get a direct strike, you can figure your antenna system it toast, period. There are anumber of ways to keep that from happening, you have to decide which is most convenient for you. I'd recommend that you do some kind of lightning protection, but can't tell you which would be best for you.
Howz that for a 'cop-out' ?
Good luck.
- 'Doc

 

[loosecannon]

Doc, the real "cop-out" would have been to post no useful information at all.
oh wait, thats what you did. LOL
LC

 

[Road Squawker]

...mount a real lightning protector (you're going to pay 60+ dollars for it) to that ground rod...

$60,................. SIXTY DOLLARS!!!!!

just build one and put that money to good use, like an echobox or sumpthin

 

[W5LZ]

Certainly different, but still a 'spark-gap' type protection. The problem with those is that during the time it takes to bridge that 'gap', your equipment is already getting the 'strike', if that makes sense. If the 'gap' is small enough to be effective then it's also probably going to be 'effective' to your transmitted signal, allowing it to go to ground too. So how do you set the 'gap' to be just large enough? I've never heard that one, have you?
- 'Doc

 

[Lil'Yeshua]

The "grounds" for Lightning and EMP Protection - Roger R. Block - Google Books
Antenna Lightning Protection | ASTRON WIRELESS


?????????

 

[Captain Kilowatt]

$60,................. SIXTY DOLLARS!!!!!

just build one and put that money to good use, like an echobox or sumpthin

By the time the voltage builds high enough (hundreds or even a couple thousand volts) to flash over the damage has already been done to your gear. Grounding for lightning is one of those things that you get back out of exactly what you put into it. If someone is too cheap to spend $60 for a decent lightning arrestor then so be it. A single arrestor by itself is NOT going to protect your equipment BTW. It takes a lot more than that and a piece of wire to a single ground rod.

As for Doc's statement about an antenna being destroyed by a direct strike, well maybe and maybe not. If not done correctly it will most certainly be destroyed along with the part of the house it was mounted on. I saw the effects on an A99 mounted on the eve of a house with no ground. The antenna disintegrated and the ensuing fire cost over $30,000 damage to the house. I bet that a hundred dollars seems cheap to spend on lightning protection now. I have also see tower and antennas get hit multiple times without sustaining any more damage than a couple burn marks. I had a 40 foot tower with a moonraker 4 take a direct strike one time. I found a couple burn marks at the tower base and a hole blown in the coax cable sheath where it was touching a metal object where it entered the house. The antenna was still useable without an issue. BTW yes the cable was disconnected from the radio gear at the time however a lot of places do not disconnect the gear. Tom, W8JI, has several strikes a year and NEVER disconnects his gear.

 

[Road Squawker]

Certainly different, but still a 'spark-gap' type protection.... So how do you set the 'gap' to be just large enough? I've never heard that one, have you?
- 'Doc

EZ,.......... measure it with a micrometer,......... and then cut it with an axe

there are many different designs,.. some are "prettier" than others

 

[Captain Kilowatt]

EZ,.......... measure it with a micrometer,......... and then cut it with an axe

there are many different designs,.. some are "prettier" than others

That reminds me of back in shop class. One guy basically had the skill set of measuring with a micrometer, marking with a crayon, cutting with an axe.

 

[TonyV225]

Deeper depths have dirt with moisture resulting in a better ground but heres a trick to remember, Your looking at a longer rod because obviously the more ground space covered the better the ground. So you will like this, You do not hyave to pound that rod straight down it can be angled Remember that your just shootin after a that large rod covering as much ground as opossible. You can take a shovel and lay that ground rod flat and 3 - 4 feet down only thing to take into consideration is its not easy to add anything as far as connect new things to the ground rod as its not accessable as it would be if you were to pound it straight leaving the connection or top accessable unless you angle it and leave top exsposed as I mentioned above.

 

[loosecannon]

Deeper depths havedirt with moisture resulting in a better fround but heres a thrick to rember

LMAO!!! sorry Tony, i couldnt help it, that was too funny. methinks it might have been a bit late when you typed this?
(i just blame autocorrect)

i think that might have to be my new sig!
LC

 

[Captain Kilowatt]

LMAO!!! sorry Tony, i couldnt help it, that was too funny. methinks it might have been a bit late when you typed this?
(i just blame autocorrect)

i think that might have to be my new sig!
LC

Looks my posts from work on the night shift while on my Smartphone.:laugh:

 

[W5LZ]

I hate to tell you this but there's no benefit in getting that ground rod 'deeper' in the dirt. It amounts to contact area, and it doesn't matter if that contact area is one inch below the surface or 8 feet below the surface. Sure, if the dirt is wetter 8 feet down that can certainly make a difference, but that's a matter of where you live. It still amounts to surface area though, so if only a few inches are in that 'wet' dirt the rest of that 8 foot ground rod is wasted area. In general, ground radials do better than ground rods if you are talking about an RF ground. A lot of ground rods mean a lot of surface area so would be the same as ground radials. But pounding in a lot of ground rods is more difficult than putting in ground radials, right? So suit your self...
- 'Doc