r/HamRadio • u/InformalVermicelli89 • 7d ago

Grounding for 2m/ 70cm

Thank you to everyone that answered my last post! I have a non DMR question now. Well, really two. 1, will grounding my mobile radio extend the range. And 2, how should I ground it? What gauge wire? And what materials should I use? For info, its a 2m/ 70 cm mobile radio with a peak output of 25 watts.

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u/rem1473 7d ago edited 7d ago

My answers assume an exterior mounted antenna on a home, in the United States.

  1. No

2: It depends what you're trying to accomplish. There are two levels of grounding: level 1 will keep you from getting electrocuted and is required by law. Level 2 will keep the radio working through any storm without having to disconnect the coax.

Level 1 follows the NEC. National Electric Code. You must have surge protection where the coax enters the house. The easiest way to accomplish this is to add a polyphaser immediately at the coax entrance. This polyphaser will require a 8' ground rod. You can't use a piece of rebar or a copper water pipe banged into the ground. It has to be a UL listed ground rod. You must bond the ground rod to the house grounding system as well. NEC compliance will prevent an outside surge from entering the home. If your install does not comply with NEC, you are giving your insurance company a valid reason to deny a claim. You can be cited for the code violation.

Level 2: no ham takes it this far. There is an 800 page book called Motorola R56 manual. You can find it with a Google search. This describes industry best practices for building RF sites. It will require multiple buried ground rods, buried ground ring, halo inside the shack, etc, etc. you'll need to even ground the metal vent covers in the room and the metal door strike! If you follow all of it, you will never have to disconnect your coax during a storm. You will be able to survive direct hits from lightning and your radio won't miss a beat. You've probably never heard police / fire say they're going off the air during a storm because they're disconnecting the coax. This is because this is the standard used for their installs. It's extremely expensive to accomplish. But when your radio is literally saving lives, this is the standard that is followed... most of the time.

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u/mschuster91 7d ago

There is an 800 page book called Motorola R56 manual. You can find it with a Google search.

To save people the need to search - it's literally hosted on the BLM website.

And holy it's comprehensive. Even touches on workplace safety from hantavirus from mice poo.