[bars] Ground post

Sun Apr 30 16:34:10 EDT 2023

https://www.amazon.com/Grounding-Bonding-Radio-Amateur-ARRL-dp-1625951493/dp/1625951493/ref=dp_ob_title_bk
Grounding and Bonding for the Radio Amateur 2nd Edition – Good Practices for Electrical Safety, Lightning Protection, and RF Management
amazon.com

"Proper Station Grounding is Important!
The second edition of Grounding and Bonding for the Radio Amateur introduces you to the current standards for lightning protection and communication systems. You’ll learn effective grounding and bonding techniques for home stations (including condos and apartments), portable and mobile stations, towers, and outdoor antennas. 

Build your ham radio station using these effective grounding and bonding techniques:

AC safety: Protect against shock hazards from ac-powered equipment by providing a safe path for current when a fault in wiring or insulation occurs.

Lightning protection: Keep all equipment at the same voltage during transients from lightning, and dissipate the lightning’s charge in the Earth, away from equipment.

RF management: Prevent unwanted RF currents and voltages (also known as RF interference or RFI) from disrupting the normal functions of equipment.”

73 de WA1QZX

> On Apr 30, 2023, at 4:28 PM, Geoffrey Feldman <geoffreyf at comcast.net> wrote:
> 
> There is no black and white answer.  Check antenna performance.   Read up on Lightning protection.  What I wrote to you is considerably condensed from the ARRL book on this subject.
>  
> It’s better to do the extra work and get it right.  It’s very good to recognize that not all grounds are the same thing – but you want to think that way? You might get away with it or – you might ruin your rig or burn down your house in a Lightning strike. The choice is still yours.
>  
> DO NOT use the ground for the house electrical system or the cable TV system ALWAYS use your own ground. It’s not OK to use an existing ground for another system – never OK for that.
>  
> You still didn’t tell us the wavelength of your antenna. That matters a lot.
>  
> Geoff W1GCF
>  
> From: KC1SOZ [mailto:kc1soz at bd5.com] 
> Sent: Sunday, April 30, 2023 4:15 PM
> To: Geoffrey Feldman
> Cc: w1hh
> Subject: Re: [bars] Ground post
>  
> So, 1) is a bad idea, 2) is ok? As I said, the mast would be a metal post buried 8 ft into the ground.
>  
> The antenna in question is one of the Hy-Gain AV-14AVQ's that I bought from Niece (and maybe a second one in a phased array later on.) 
>  
> On Sun, Apr 30, 2023 at 4:04 PM Geoffrey Feldman <geoffreyf at comcast.net <mailto:geoffreyf at comcast.net>> wrote:
>> “Ground” has different meanings.  The short answer to your question is: No.
>>  
>> Explanation: In this particular case, what you propose is ill advised.  The electrical system ground post is for the electrical system.  RF or Lightning that is not absorbed by that post would then go into the residence.  Similarly surges from the power distribution system could go to your equipment.  Yes, people do this and get away with it but that doesn’t mean it’s a good idea or that it’s the same idea at different locales.
>>  
>> If you are sure it’s buried 8’ STRAIGHT DOWN into the ground then it’s probably OK for lightning strike management.  (However there should be precautions for where the feedline goes into your home but that’s another story.) Where Lightning is concerned there is no perfect solutions just to pray that yours is good enough.
>>  
>> If you are asking about an effective counterpoise then it may not be satisfactory.   The answer depends on soil conditions where you are but generally wires laid along the ground or just beneath the turf will provide better antenna performance (you didn’t mention the wavelength, so for shorter wave lengths there may be easier but adequate solutions)  Measure performance and if in doubt – add more horizontal wires along the ground.  
>>  
>> In both cases, what you suggest may not prevent common mode currents returning through the outer conductor of the Coax. This is bad but can be corrected with a choke near the entry point to the house.  If the E-field of your antenna doesn’t find a suitable place to complete its circuit (counterpoise or opposite side in a dipole) then it will find other paths. Antenna performance will suffer, impedance will be off etc.  
>>  
>> Back to the word “Ground” – the word is used in other ways such as “equipment ground, a no load safety return for electrical failure (the third prong of a plug).   It can mean a comment point that stated voltages in a circuit are measured from.  In other radio systems, it can mean a suitable return path for the e-field such as the metal body of a car, a radar dish etc.    If you were to sink 8’ ground rods 10 feet apart or so you would likely see voltage between them, pointing out that ground is never absolute, it’s always local.
>>  
>> By the way, do not use a ground established for the buildings Cable TV service. That can make you super unpopular.
>>  
>> Putting in a new ground can be a lot of fun.   When in doubt – do that.   Get the standard ground stake sold at Lowes or Home Depot.   Get up on a step ladder to start it in.  A solid carpenters hammer is enough.  It may seem stuck, keep banging and hopefully you will break what it’s stuck on.  (Dig safe is a good thing too)
>>  
>> That should do it
>> Geoff W1GCF
>>  
>>  
>> From: bars [mailto:bars-bounces at w1hh.org <mailto:bars-bounces at w1hh.org>] On Behalf Of KC1SOZ
>> Sent: Sunday, April 30, 2023 3:38 PM
>> To: w1hh
>> Subject: [bars] Ground post
>>  
>> When putting up a ground-mounted vertical antenna...
>>  
>> 1) Is it OK to attach the ground strap from one of the u-bolts to the residential grounding post already buried in the ground?
>>  
>> 2) Is a grounding strap strictly necessary if the mast to which the antenna is attached with the u-bolts is itself a metal post buried almost 8 feet into the ground?
>>  
>> 73,
>> KC1SOZ
>> Juan
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> bars at w1hh.org
> http://mail.w1hh.org/mailman/listinfo/bars_w1hh.org

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