grounding.... question..

[TheJerk]

i have heard a few people say they dont ground there antennas..

From what I have read, and gathered from that reading; grounding based on NEC code isn't to take a direct lightning strike, its to give static buildup a place to discharge to prevent a strike. Static builds up because of wind friction and antenna material...some are worse than others from what I read...and some antennas just lend themselves to be better dissipators than others.

 

[CalebATC]

wow..... how come you packing it up you moving?????? i have heard a few people say they dont ground there antennas..

Yep- Moving to north Georgia. Leaving the crappy Florida! I won't miss anything except the milair

I didn't even think of grounding mine, since I only had it up 4 months. Although I can say it did almost get strucken a few times though. Especially during storms (Florida=Lightning Capitol of World) so I got a little scared and took of my scanner. It sounded like pop corn haha, and I watched lightning strike about 200 feet away from it once while outside. Scared the living crap out of me!

 

[Monster75]

Yep- Moving to north Georgia. Leaving the crappy Florida! I won't miss anything except the milair

I didn't even think of grounding mine, since I only had it up 4 months. Although I can say it did almost get strucken a few times though. Especially during storms (Florida=Lightning Capitol of World) so I got a little scared and took of my scanner. It sounded like pop corn haha, and I watched lightning strike about 200 feet away from it once while outside. Scared the living crap out of me!

first off good luck with the move hope all works out well for ya... 2nd wow on the lightning.. lucky you did not get a direct strike. but thats why some people i talked to around town here said they dont ground because no matter how well you ground a direct hit will kill anything.... and all grounding is for is to help with static charge or surcharge from a near buy strike, i have nto got all my stuff hooked up yea as i am am still getting all my stuff i need so i can hook it up right the first time... but i am leaning towards a ground block to run the cable too then ground wire from the block to the rod..... and call it the day...LOL

 

[CalebATC]

LOL.... in Michigan you shouldn't have a problem with lightning. I remember numerous times I have sat on the porch outside and have lightning strike all around me. One time I was watching TV and one struck the power pole next to my house.

But yes, I look as it is if your antenna gets struck, it's not going to be pretty. But yes, It will get alot of static away.

Do your setup right! Good luck on getting everything up! It will pay off om the end.

 

[hossinkilgore]

Antenna grounding

I know this sounds rather simplistic compared to the previous discussion, but I plan to install a metal tripod tower buried in the ground. On that I plan to attach Watson discone antenna with a “N” connector to LMR 400 cable and run it to a multicoupler inside my home. From there I will go to my scanners.
Am I properly grounding?

Thanks for your input.

 

[NoCoFire]

From what I remember reading of the NEC (assuming the antenna is "house mounted"):

...the mast should be bonded to a dedicated grounding rod using a minimum 10ga wire.

...the grounding rod should be bonded to the house grounding system using 6ga copper wire.

...a shield ground should be used on the coax.

Is this correct? The PolyPhaser would be above and beyond NEC, correct?

I was thinking of mounting a 102" whip on the ridge of the house because of the winds at this location...but I'm reluctant to now, since it is the highest location within 300 feet. I am actually thinking I may go back to an original plan and install a short pipe "tip up" mast/tower...to get the antenna off the roof.

I have an ST-75 (I think that's the model?) and I know there is no way it will survive the winds that come through here (with the storms)...the reason for a simple SS whip idea.

...the mast should be bonded to a dedicated grounding rod using a minimum 10ga wire.

Yes doesn’t 10ga wire seem a little too skimpy? But then again this is not a system designed for a direct strike. This is a system that is designed to dissipate static caused by nearby strikes, wind, etc. I used 8 ga thhn and bonded it directly to the grounding rod. Apparently, and I am certainly no expert, when lightning strikes nearby there can be many leaders that attract themselves towards the main bolt, these leaders can originate from things that do not have the preferred ground as the direct bolt but have some path to ground. Again I am not an electrician or any kind of expert in this field.

...the grounding rod should be bonded to the house grounding system using 6ga copper wire.

Yes. I used 4 ga because my father in law had some left over from another project and IMHO this would be a place to not skimp.

...a shield ground should be used on the coax.

Yes, these do not have to be complex but remember NEC is minimum

Is this correct? The PolyPhaser would be above and beyond NEC, correct?

I believe that it would because the polyphasers that I have seen all have, and I believe they would need in order to work properly, a ground attachment lug. So essentially they are working like a coax ground shield but have the gas discharge tube as an extra measure. This is probably why they are so pricey and probably the way to go. They are in service at my station along with 1/2" heliax.... clean up drool...

You will notice on this picture below from http://wsmweather.co.uk/wp-content/uploads/2010/05/lightning-strike-tree.jpg

The leader running from the antenna on this farm house towards the main bolt. I would not consider this a direct strike but, again IMHO, it is probably a lot of juice produced and hopefully the grounding that I described via NEC 800 would help..... but when a storm is approaching I just unplug even though my system is protected, at least to nec plus some additional "beef" in regards to wire gauge.

Remember lighting is, from what I can gather from reading many posts, looking at other websites like:

Antenna Grounding - Mike Holt's Forum

Mike Holt's Forum - Search Results

Recommended Grounding Guidelines - National Lightning Safety Institute

is unpredictable.

Personally If I had the resources I would put up a tower. Good Luck!

 

[NoCoFire]

Hoss

Get a copy of NEC 800 (National Electric Code) and ground the coax right when it comes into your house and ground the antenna mast.

did you already order your LMR with the connectors or are you doing it yourself?

NoCoFire

 

[hossinkilgore]

I had them professionally installed from the manufacturer

 

[NoCoFire]

I know this sounds rather simplistic compared to the previous discussion, but I plan to install a metal tripod tower buried in the ground. On that I plan to attach Watson discone antenna with a “N” connector to LMR 400 cable and run it to a multicoupler inside my home. From there I will go to my scanners.
Am I properly grounding?

Thanks for your input.

Hoss

Get a copy of NEC 800 (National Electric Code) and ground the coax right where it comes into your house and ground the antenna mast. Bond the grounding rod with your house electrical system. Consult a professional and keep on researching this.

did you already order your LMR with the connectors or are you doing it yourself?

NoCoFire

 

[TheJerk]

...the mast should be bonded to a dedicated grounding rod using a minimum 10ga wire.

Yes doesn’t 10ga wire seem a little too skimpy? But then again this is not a system designed for a direct strike. This is a system that is designed to dissipate static caused by nearby strikes, wind, etc. I used 8 ga thhn and bonded it directly to the grounding rod. Apparently, and I am certainly no expert, when lightning strikes nearby there can be many leaders that attract themselves towards the main bolt, these leaders can originate from things that do not have the preferred ground as the direct bolt but have some path to ground. Again I am not an electrician or any kind of expert in this field.

...the grounding rod should be bonded to the house grounding system using 6ga copper wire.

Yes. I used 4 ga because my father in law had some left over from another project and IMHO this would be a place to not skimp.

...a shield ground should be used on the coax.

Yes, these do not have to be complex but remember NEC is minimum

Is this correct? The PolyPhaser would be above and beyond NEC, correct?

I believe that it would because the polyphasers that I have seen all have, and I believe they would need in order to work properly, a ground attachment lug. So essentially they are working like a coax ground shield but have the gas discharge tube as an extra measure. This is probably why they are so pricey and probably the way to go. They are in service at my station along with 1/2" heliax.... clean up drool...

You will notice on this picture below from http://wsmweather.co.uk/wp-content/uploads/2010/05/lightning-strike-tree.jpg

The leader running from the antenna on this farm house towards the main bolt. I would not consider this a direct strike but, again IMHO, it is probably a lot of juice produced and hopefully the grounding that I described via NEC 800 would help..... but when a storm is approaching I just unplug even though my system is protected, at least to nec plus some additional "beef" in regards to wire gauge.

Remember lighting is, from what I can gather from reading many posts, looking at other websites like:

Antenna Grounding - Mike Holt's Forum

Mike Holt's Forum - Search Results

Recommended Grounding Guidelines - National Lightning Safety Institute

is unpredictable.

Personally If I had the resources I would put up a tower. Good Luck!

Thanks, I've seen most of those links. I agree that NEC is minimal...I would definitely do more.

I've been thinking of a simple tower...basically a "flagpole" type tip-up since it will only have the scanner antenna...would only need to be about 15 feet tall...a 21-foot piece of 2-inch pipe buried in some concrete would do nicely.

One thing I read about using a tower (big tower) was to place the antenna below the top of the tower...basically using the tower as the lightning rod, protecting the antenna.

A spark-gap deal can be made from spark plugs...I might try that since its a receive only station.

 

[NoCoFire]

Thanks, I've seen most of those links. I agree that NEC is minimal...I would definitely do more.

I've been thinking of a simple tower...basically a "flagpole" type tip-up since it will only have the scanner antenna...would only need to be about 15 feet tall...a 21-foot piece of 2-inch pipe buried in some concrete would do nicely.

One thing I read about using a tower (big tower) was to place the antenna below the top of the tower...basically using the tower as the lightning rod, protecting the antenna.

A spark-gap deal can be made from spark plugs...I might try that since its a receive only station.

Great! If you dont mind take pictures and post them when you get done!

The Amateur Amateur: Tipping the Mast, Topping the Hill

I used to work on a farm that used irrigation pipe made out of aluminum. I always thought that it may make a good mast but when you moved each section it would kind of wobble in the middle, so maybe it would need to be guyed... maybe you dont want that (more stuff to weed-eat around).

Good Luck and let me know how you progress!

(PS Dont skimp on the coax, from reading around it looks like LMR-400 is the way to go if you can)

 

[TheJerk]

Great! If you dont mind take pictures and post them when you get done!

The Amateur Amateur: Tipping the Mast, Topping the Hill

I used to work on a farm that used irrigation pipe made out of aluminum. I always thought that it may make a good mast but when you moved each section it would kind of wobble in the middle, so maybe it would need to be guyed... maybe you dont want that (more stuff to weed-eat around).

Good Luck and let me know how you progress!

(PS Dont skimp on the coax, from reading around it looks like LMR-400 is the way to go if you can)

I have 100 feet of RG8 and about 1500 feet of RG6QS available...

I doubt I would even make it tip...at 15-feet, I could easily reach that with a 12-foot step ladder, and my antenna of choice is a 8 foot SS whip (not ideal for a scanner but durable).

 

[NoCoFire]

another good resource

http://www.dxengineering.com/techarticlepopup.asp?ID={A0896F49-0C15-4885-9969-EC0AB4B210F8}

 

[Monster75]

I have 100 feet of RG8 and about 1500 feet of RG6QS available...

I doubt I would even make it tip...at 15-feet, I could easily reach that with a 12-foot step ladder, and my antenna of choice is a 8 foot SS whip (not ideal for a scanner but durable).

if i was you i would get some LMR400 i use to have quad shield rg cable worked good but have since got lmr 400 and it makes a huge huge difference...

 

[W6KRU]

if i was you i would get some LMR400 i use to have quad shield rg cable worked good but have since got lmr 400 and it makes a huge huge difference...

How so?

 

[Monster75]

How so?

i get less interference , better signal strength, and less db loss.... i always thought it was not that LMR makes a big difference, but once i bought some all the people who tell me it would are right.. lmr 400 made it like a whole new system..

 

[W6KRU]

i get less interference , better signal strength, and less db loss.... i always thought it was not that LMR makes a big difference, but once i bought some all the people who tell me it would are right.. lmr 400 made it like a whole new system..

Ok. Theoretically they should be pretty similar when using short (<100') runs. The difference would probably be less than an s-unit at vhf and possibly up to an s-unit at 800MHz. See this chart:: Strong Signals - Co-ax Cable

 

[TheJerk]

Yeah, I'm not in a position to buy a different coax...would be using what I got on hand. I want to remember the RG6 is less loss at higher frequencies? My run would be less than 100 feet. My RG8 is the nearly 0.5 inch diameter stuff, and 95% copper shielding...not the thinner 8X. I originally had the RG8 for my base CB...but have since ditched that idea for this new place.

I feel coax quality has more to do with signal than the actual coax itself (until you get into 100+ foot runs)...some coax is better than others (even within the same class, such as RG6 to RG6 comparisons).

I actually decided to do something a little different. We are going to build a decorative outdoor wood structure near the back of the house. I'm simply going to use a 20-foot 6x6 in one of the upright locations, then run my existing 1-inch "tip-up" (I had this at the old place) off that...I figure that should put the tip of the antenna nearly 32 feet up...16 usable feet of 6x6, eight usable feet of steel mast, and eight feet of antenna.