Antenna grounding

[jsouth]

I've been thinking a lot about antenna grounding. I don't live in an area with a lot of lightning but it does happen from time to time. I've been reading on the interwebs about some that say it is absolutely critical but others say that they never ground their antennas because grounding them acts as a bullseye for lightning strikes. I would love to hear from those that are for and against, if possible. If I decide to ground it then what are the best ways to do so and how to keep it budget friendly.

My antenna is an Ed Fong encsased in PVC and mounted directly to the side of my house at the roof line with 2 metal U-straps. 

 

Thank you in advance.

[gman1971]

I didn't thought much of grounding antennas until I moved to my current house and needed every bit of range I could muster. Grounding the antenna made a significant reception difference, as in, it went from ~5 miles max to ~15 miles easy... grounding the antenna did lower the dB floor according to my spectrum analyzer, thus substantially improving reception range.

 

To do grounding I read a lot of advice from people who do commercial tower installations and the NEC guidelines, etc.

 

So, here is what worked for me:

 

I purchased two Times Microwave Arresters, both N female, both Low PIM (low Passive Inter-Modulation), and both are bolted to the metal mast that holds the antenna(s) and the mast (1.25" steel pipe) is grounded using two copper clamps and a 10AWG wire to the house ground rod electrical box.

 

The first arrester is placed right before the antenna, at the top of the mast. The second one is at the bottom of the mast. The short run between the antenna and the first arrester is a 4 foot LMR400 patch, coiled twice and both ends are silver plated connectors for low PIM. Then, from the first arrester (at the top) to the 2nd arrester at the bottom of the mast there is a 20 feet Heliax 1/2" cable run, both are N male ends and tri-metal low PIM connectors. The bottom arrester has a 90 degree elbow (silver plated) and another Heliax 1/2" 6 feet run, (both ends of this cable are also tri-metal low PIM) to the input of the "radio box" ... Inside the radio box I am using MILSPEC RG-214 patch cables with N male silver plated connectors for low PIM. The only connections that have any chrome plating are the antenna's SO239 and the Vertex Standard EVX-5300's mini-UHF connector.

 

As you can see, I ditched all the UHF connectors and my SWR no longer creeps over time due to connectors being exposed to the crap weather. It was a "Copernican turn" for me, as all I had before was 239 stuff... glad I moved away from those, and from chrome plating... which caused a host of problems with the massive 1400 Candelabra tower sitting less than 2 miles from my antenna mast...

 

All my radios are connected to a solar panel array and a 12VDC battery bank, thus not sharing anything electrical with the house, but the negative (ground) of the battery bank is connected to the same ground 10AWG wire the antenna mast is.

 

G.

[JB007Rules]

I didn't thought much of grounding antennas until I moved to my current house and needed every bit of range I could muster. Grounding the antenna made a significant reception difference, as in, it went from ~5 miles max to ~15 miles easy... grounding the antenna did lower the dB floor according to my spectrum analyzer, thus substantially improving reception range.

 

 

This is good information.  I'll be getting my DB408-b some time this week and with it being long and metal I obviously am going to ground it with 6 gauge wire even for the short testing time at my house.  I didn't think that grounding the antenna alone would increase coverage?  I don't understand why that would be the case?

 

Thanks!

[gman1971]

I didn't thought it would either... but when you're pumping 50W mobile on GMRS and the base can't hear you further than 5 miles desperation grows rather quickly.. so I tried everything... and the range came when I grounded everything. So whatever my problem with reception was, grounded fixed it.... the rumor has it that vertical end fed antennas have issues with fully decoupling from the feedline... by grounding it thoroughly it lessened the issues, rumor also says that grounding could fix the nulls on the antenna radiation pattern.... and deal with common mode currents on the coax  which create noise... but like I said, I don't know why, but my range improved quite a bit by grounding the antenna.

 

The DB408 is probably a far superior antenna to the 39.95 TRAM special...  folded dipoles tend to be just better antennas...

 

 

G.

 

This is good information.  I'll be getting my DB408-b some time this week and with it being long and metal I obviously am going to ground it with 6 gauge wire even for the short testing time at my house.  I didn't think that grounding the antenna alone would increase coverage?  I don't understand why that would be the case?

 

Thanks!

[JB007Rules]

Thanks for that information!

 

I can't wait til this DB408 comes in!  Any day now!!!  I ordered it (again) last week on Tuesday.  Yeah, one issue I've had with the cheap $60 antenna (And everyone said this would be a problem so I'm not surprised) is that for example my wife was about 8 miles out at her parents house on a 45w mobile and I could hear here LOUD AND CLEAR transmitting back to the machine but me being at home transmitting super clean to the repeater it couldn't get back out to her.  So essentially it could hear VERY well but the mouth just couldn't get it back to her 8 short miles away.

 

I've also witnessed this when travelling out west on Interstate 88.  Due to the geography I'm at a HUGE elevation advantage when shooting west.  At any rate I was able to burp the repeater at almost 22 miles but it couldn't spit it back out to me.  Always a transmitting shortcoming.  With a correct antenna and proper ground I think we'll be cooking with gas here soon.

[gman1971]

Yeah, I had the same issue the base could be heard for 20+ miles, but it couldn't hear anything beyond 5 miles... 

 

Hope the DB408 works out! Also, perhaps too much gain is too much gain? If you live in a hilly area might be better to run a lower gain antenna?

 

G.

 

Thanks for that information!

 

I can't wait til this DB408 comes in!  Any day now!!!  I ordered it (again) last week on Tuesday.  Yeah, one issue I've had with the cheap $60 antenna (And everyone said this would be a problem so I'm not surprised) is that for example my wife was about 8 miles out at her parents house on a 45w mobile and I could hear here LOUD AND CLEAR transmitting back to the machine but me being at home transmitting super clean to the repeater it couldn't get back out to her.  So essentially it could hear VERY well but the mouth just couldn't get it back to her 8 short miles away.

 

I've also witnessed this when travelling out west on Interstate 88.  Due to the geography I'm at a HUGE elevation advantage when shooting west.  At any rate I was able to burp the repeater at almost 22 miles but it couldn't spit it back out to me.  Always a transmitting shortcoming.  With a correct antenna and proper ground I think we'll be cooking with gas here soon.

[Riktar]

In my case I am running an Ed fong antenna for hitting the local repeaters and a Yagi for simplexing with my brother. The antennas are at 2 different ends of my 2 story house (Both are in the attic, NOT outdoors) which is shaped like a "T". The 2 LMR400 cables are joined togther near the radio and are handled by a coax switch which works quite well. The difference between directly hooking each antenna to the radio vs having the them fed into the switch with a short 1 foot feed to the radio is so small it's not worth measuring. I am using this setup since the Ed Fong Omni aint cutting it for simplexing to my brother. Which is interesting in itself since the repeater I frequently use is 28 miles away as the crow flies and my brother is barely 13. We are talking about 2 compass directions that are nearly 90 degrees apart. Then again I do have a big fat hill between my brother and I and I think there is little to no elevation issues to the repeater.

 

But I digress.

 

So for grounding: Should I have a lightning arrestor at each antenna and one between the coax switch and the radio? Or is putting the ground between the radio and the Coax switch enough? If I can avoid crawling around in my attic anymore than I have already done that would be great.

 

Lastly, I wonder if I could just use the water entry (I have well water) pipe for the earth ground?

 

Fascinating topic!

[Jaybee]

Lots of good detailed information here.

 

https://www.youtube.com/watch?v=ZpU3Sme7lH4