[bars] Ground post

[Geoffrey Feldman]

“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] 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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