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How to ground my G5RV

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KD9NSL, Dec 10, 2019.

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  1. KD9NSL

    KD9NSL Ham Member QRZ Page

    New Ham here. I have my G5RV installed on the roof of my house with the legs going to trees on the sides of my house. I know what my antenna has to be grounded before it enters my shack (which is in the basement) I am planning on grounding my antenna directly to my house ground rod which is right below the antenna feedpoint. Can I just use a clamp to connect the coax to the ground rod? I am having a hard time finding any information how to ground coax directly to a ground electrode.
     
  2. WA7ARK

    WA7ARK Ham Member QRZ Page

    I cut the coax, install two PL259s, and use a threaded coax bushing, like this one. The threaded bushing goes through a metallic plate, along with other coax bushings (for different antennas) on an outside wall of the house right above the ground rod. I use a short #6AWG bare copper wire to connect the metallic plate to the ground rod, using a split-bolt at the ground rod.
     
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  3. K7TRF

    K7TRF Premium Subscriber QRZ Page

    Yeah, the antenna itself doesn't really need to be grounded but the shield of the coax feed line should be grounded where it enters the house. And yes, your method of bonding the coax shield to the existing house ground rod at the AC service entrance is really about the best approach you can take.

    There are several ways to ground that coax shield. You can use a surge suppressor which isn't strictly required by code but it gives you a convenient way to bond your coax shield to the main ground rod either by using a clamp on ground rod mount or a short heavy gauge bonding wire between the suppressor and the ground rod. You can also just use something like a coaxial barrel connector bonded to the ground rod or even just strip back some of the coax outer insulation and bond the coax shield to the ground rod using something like a hose clamp to connect the ground bonding conductor to the coax shield. If you go that latter route then re-wrap the connection to weather proof it.

    If you go the surge suppressor route you can get convenient ground rod clamp kits like this from DX Engineering or other places that make the job easy assuming you have a bit of exposed ground rod to work with: https://www.dxengineering.com/parts...MIq5bdq9-r5gIViONkCh1F_g24EAQYASABEgIai_D_BwE

    There are other perhaps more cost effective approaches using standard ground rod bronze clamps that you can buy at hardware stores or electrical supply houses.
     
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  4. KA0HCP

    KA0HCP XML Subscriber QRZ Page

    You need a surge/lightning arrestor. They are sold by all the ham vendors. Major manufacturers are DX Engineering, Alpha-Delta, Polyphaser, MFJ.

    You will need to buy a clamp to attach to the ground rod.
    Examples:

    [​IMG]

    [​IMG]
     
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  5. KD0CAC

    KD0CAC Ham Member QRZ Page

    Save $$$ , look for pass-through-panel on MFJ or any other sites to get an idea , then just make one .
    This is to ground the shield , but grounding is a big subject I would give it thee headings , RF ground , lightning ground , AC ground .
    For the center wire of the coax just use a non-inductive resistor in the area of 9-10,000 Ohms to ground .
    Grounding is a system that is interconnected .

    Then try to see what can be left-out or reduced for your conditions , lightning is the biggest issue , to get to a " ham station " - not needed to operate during a lightning storm like a commercial radio / TV station - Motorola R56 - choose your own source for down-loading a free pdf ?
    While looking I found this for more info , https://wiki.radioreference.com/index.php/RF_Engineering

    Do not forget to checkout sticky on QRZ , getting big , for grounding http://forums.qrz.com/index.php?forums/antennas-feedlines-towers-rotors.33/

    Point being the more you learn / understand the better your choices for getting the most out of your labor & money .
     
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  6. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    You can make a grounding strap, for less than a dollar, that is like what Andrew has sold, for a much higher price, to ground the shield of their Heliax transmission line.

    coax-grounding-1.jpg

    Glen, K9STH
     
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  7. W2AAT

    W2AAT XML Subscriber QRZ Page

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  8. KD9NSL

    KD9NSL Ham Member QRZ Page

    Can you send me a picture if possible?
     
  9. AI3V

    AI3V Ham Member QRZ Page

    Yes, that will be fine.

    Dont wa$te money on any sort of "surge supressor"

    Rege
     
  10. KF5LJW

    KF5LJW Ham Member QRZ Page

    [insulting personal insults and attacks edited out by moderator]

    Here is what you need to know and the best practice to protect your home, equipment, and your family if you give a crap about such things. To start and prove Mr Dangerous Regie is dead wrong comes from NEC. This is not a recommendation, it is mandatory for all Transmitting Stations end of story no debate or defense.

    810.57 Antenna Discharge Units — Transmitting Stations

    Each conductor of a lead-in for outdoor antennas shall be
    provided with an antenna discharge unit or other suitable
    means that drain static charges from the antenna system.


    When you see the word SHALL BE in any type of code means exactly that, thy shall do this or else you fail and do not get to turn anything on enforcable by local sheriff and police if you wanna get tough. Now if this were say SATV, CATV, or RX only antenna then all you are required to do is bond the coax. However since you have a Transmitter (TX power does not matter, any transmission power) NEC Article 810 III has additional bonding and grounding requirements for CB and Amateur Radio Operators.

    OK now that we got the Code stuff out of the way, lets dive in on best practice. Without a doubt the best practice is to bring your coax in where your AC Service enters. Use an ADU to meet two requirements of bonding the coax shield to earth, and an ADU to discharge the center conductor before entering.

    Nothing really tricky required. Look at your ele3ctric meter and you should see a bare ground wire going to dirt. This is called the Ground Electrode Conductor (GEC). It runs from the Ground Electrode System (GES) to the Grounded Circuit Conductor from the Utility located in your Service Disconnect Device. (most likely the meter can). Use a very short piece of #10 AWG minimum or larger solid conductor to connect the ADU to GEC as close to dirt as possible, below grade is even better.

    You do that and you have a dream of a ground system better than 99% of all ham radio operators. The trick or secret what makes this method so effective is this is how professional operators protect their equipment. What you are doing is making a Single Point Ground. No matter what happens you electrical ground and Radio Ground will always be at the exact same potential because they both originate at the same point. Take any volt meter, short the leads together and measure the voltage. You will get 0 volts every time even if the test probes are touching a 10,000 volt utility line. No outside current can enter the house. It has no place to go.

    Not only will it be safe, but will eliminate just about all Common Mode and RFI issues assuming your transmission equipment is working properly. The antenna circuit is the most important part of a radio system. A Contest grade receiver sounds like chit on a crappy antenna system. A crappy entry level radio will sound great with a good antenna. Do as suggested above and you well ahead of most operators who brought their coax inside elsewhere.
     
    Last edited by a moderator: Dec 19, 2019
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