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#1 mbrun

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Posted 16 July 2020 - 04:54 PM

About 10-years ago when I obtained my original GMRS license the FCC had a limit on GMRS antenna height. It was 20 foot above the tree or building to which it was mounted (roughly speaking). In the current regulations that 20 foot limit seems to have been complete removed. Instead, 95.1741 (regarding height) merely redirects to 95.317 that seems to indicate antennae structure over 200 foot may need to be registered with FAA.

So, I am curious, has the 20 foot limit truly been removed? Is it now 200 feet? If restriction is specified somewhere else if the CFR, where would I find it?

Michael


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#2 rodro123

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Posted 17 July 2020 - 05:24 AM

§ 95.51 Antenna height.
(a) Certain antenna structures used in a GMRS system and that are more than 60.96 m (200 ft) in height, or are located near or at a public-use airport must be notified to the FAA and registered with the Commission as required by part 17 of this chapter.


#3 BoxCar

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Posted 17 July 2020 - 07:15 AM

The 6.1 meter (20 foot) rule does not apply in this instance. If the height of the structure AND antenna is greater than 200 feet overall it needs to be registered. Several Part 90.20 entities found this out when the FCC cited them.


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#4 mbrun

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Posted 17 July 2020 - 10:51 AM




§ 95.51 Antenna height.(a) Certain antenna structures used in a GMRS system and that are more than 60.96 m (200 ft) in height, or are located near or at a public-use airport must be notified to the FAA and registered with the Commission as required by part 17 of this chapter.




Antenna height.


Rodro123, I believe 95.51 was removed as part of the 2017 FCC update. My current understanding is that 95.1741 took its place.


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#5 berkinet

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Posted 17 July 2020 - 11:08 AM

.,,95.51 was removed as part of the 2017 FCC update. My current understanding is that 95.1741 took its place. ...

That is correct. However note that part 95.51 then refers to 47 CFR § 95.317 which provides restrictions for all personal radio services under part 95. However, the restrictions are pretty much the same as they were under section 95.51. But with the addition of additional restrictions if you’re near a military installation or airport.

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#6 mbrun

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Posted 17 July 2020 - 12:13 PM

So are you concluding that the limit is 200 feet, the same as I am?


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#7 berkinet

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Posted 17 July 2020 - 12:20 PM

So are you concluding that the limit is 200 feet, the same as I am?

Absent any other circumstances, yes.

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#8 tweiss3

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Posted 17 July 2020 - 01:19 PM

To clarify further for you guys, that 200' limit is the cutoff for requiring FCC/FAA filing and paint/lights. You can go above 200' if you want to deal with the hassle.


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#9 BoxCar

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Posted 17 July 2020 - 02:22 PM

IIRC the FAA regs state the structure has to have a light at its highest point. It's difficult to get an antenna to work properly when it has a light and power cable on it. The issue was uncovered when antennas started being put on bridges more than towers,


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#10 mbrun

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Posted 17 July 2020 - 02:45 PM

My ultimate reason for asking the question has to do with my surroundings. My home is surrounded by acres of trees on three sides. I am considering an antenna on the home and originally figured 20’ above the home. But then I thought, I wonder if I could attach to house but put up high enough to peek out above the trees.

Not sure if I will do that or not, but its sounds like that is legal if I decided to go that way.


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#11 JohnE

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Posted 17 July 2020 - 02:52 PM

what is it going to take to clear the trees.
also what are the local rules on antenna height. some places have restrictions on height and fall zones.


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#12 mbrun

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Posted 17 July 2020 - 04:08 PM

Good point on local ordinances. I will need to look into that.

I image it would take 60 foot +/- to clear the trees.


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#13 JohnE

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Posted 17 July 2020 - 06:16 PM

ran into that problem. found a way around it though.


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#14 mbrun

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Posted 04 August 2020 - 07:12 PM

I have ordered a Comet 712EFC Antenna and some LMR400 cable to begin testing at my place.


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#15 n4gix

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Posted 06 August 2020 - 06:25 PM

I was once offered space on a very large tower array (2 towers with a bridge at the top) in Crete, Illinois. They had a UHF antenna and 1 1/2" hard line at 350'...

 

I was all excited until I was informed that they charge $1/ft' per month. No way I could afford $350/month :blink:



#16 mbrun

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Posted 10 August 2020 - 06:27 PM

A bit too much for the hobby of an individual I would say.

I was once offered space on a very large tower array (2 towers with a bridge at the top) in Crete, Illinois. They had a UHF antenna and 1 1/2" hard line at 350'...

I was all excited until I was informed that they charge $1/ft' per month. No way I could afford $350/month :blink:



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#17 O-B-1

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Posted 18 September 2020 - 01:32 AM

I have ordered a Comet 712EFC Antenna and some LMR400 cable to begin testing at my place.


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Testing done? How did it go? What radio are you using?


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#18 mbrun

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Posted 18 September 2020 - 06:38 AM

Testing done? How did it go? What radio are you using?


Yes and no. I have commented on some of my activities in other posts.

At present, the highest I have been able to test has been 41’ to top of antenna. Still strategizing how I can the get the antenna to 60’ to button of antenna in a temporary manner at limited expense so more coverage tests can be performed. What I am wanting to determine is, if I clear the trees only marginally, will that get me the local simplex coverage I seek (solid coverage >= 3 miles base to HT and >= 9 miles base to mobile). If my simplex coverage does not increase notably at 60’, then I won’t go for the expense for permanent installation.

I have been pondering the purchase of DX engineering 46’ telescoping mast, but that still does allow me to clear the trees.

So yes, I am done testing for now. No, I have not completed testing at my desired height...yet.

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Michael
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