gortex2

The top brass nut is what I meant. If its not recessed on the bottom to accept the plastic ring I'm not sure what the spacer is for. A normal 3/8" mount is pictured below and you can see the recess in the brass nut.

 
A standard NMO wouldl ook like this  
 

Thanks @Sshannon I missed that in the firt post. So I guess my original statement stands. An antenna 10' off the gorund with a 5 watt UHF repeater into 50' of LMRish cable and an antenna isn't going to cover too far. I think many have this misconception that they can buy stuff throw it up and talk 50 miles casue other talk about that on the forum. Throwing an Midland/RT97 on a silo thats 150' in the air and field all around will cover better than the earlier one. I posted once previously about my Motorhome experiences.  With 15' of cable and a good Laird antenna I got difference coverage depending on where I parked. 
 

He said:
 

A quarter wave antenna pattern looks much like a round ball. A gain antenna pattern takes more the shape of a football, or even an exaggerated football (ellipse). 
I've never gone wrong performance wise with a 1/4 wave... in UHF, VHF, 800... 
Nothing against the gainers, they have their place.
Just an observation, but usually I see HAM radio (I am a HAM too) using gain antennae because we try to do the most with the least power. Commercial and GMRS largely used fixed power (even though there are adjustable power GMRS radios now) and many times have more power than they really need, so any marginal effect of a higher gain antenna is not seen or even known. That's an opinion, don't anyone get sideways.  

Is the top nut flat on the bottom ? you didn't show that. You need the teeth on the bottom of the mount up against the steel bracket as well as the top nut. 
 
 

All of your radios are H.A.M. radios, so they probably won't be able to transmit on the GMRS repeater.. But, if they are unlocked, you can ignore the 'output' tone until you know what you're doing, and just use the input tone by entering that in your repeater-channel setup which will be specific to each radio.
You have a lot to learn - there are no simple, quick answers.. Unless you had real GMRS radios, then it is actually pretty simple and quick to use a repeater.. but you have H.A.M. radios.. sooo... 

Hi. I have 4 of the mxt275 radios. It’s been awhile since I’ve programmed one, but If I recall correctly, after choosing the repeater channel that corresponds with the repeater frequency you want, use the instructions in your manual for selecting a “Privacy” code, except choose tC in step 2. 
Maybe this will get you going in the right direction.

If you're considering a Motorola Repeater Station for your project, get something a little more modern like a Quantar with a professional quality duplexer like an EMR Corp type quality and a Laird FG4603 basestation antenna.
You'll wish you did in the long run if you go cheap and use crap equipment.
There is a reason why public safety agencies do not use consumer and amateur radio grade equipment on their systems.

GMRS wasn't intended for what you are looking for. If I heard a call I'd change channel or not answer. 

As said forget the repeater. Just use simplex. IF you are going to use it when you get someplace else using the travel tone would be prudent. 

I chose a Vertex VXR7000 and a Tram1486.  I chose the 1486 due partially to its very low wind-profile.

In this case I’d leave the repeater in the truck   For these purposes it seams like a useless brick.  

Did you read the FCC Part 95 rules and regs before you acknowledged by signing the license application stating that you are familiar with said rules?
If so, then you should be familiar with which freq of the paired frequency should be the transmit freq to the repeater and which freq should be the receive freq from the repeater pursuant to Section 95.1763 sub sections (a) and (c).

It was alwasy common to test in the middle when we used CB and think GMRS would be the same. With that said repeaters are 467.xxx and simplex is 462. If you use simplex 99% of the time I'd test on a middle 462.xxx channel. For instance a 1/4 wave should work fine across the board. It realyl depends on useage. For my SAR stuff we always use the National SAR channel for tunign as thats the most important channel we use. Other channels are repeaters and a portable works fine so worring about a great single from the mobile is less concerning. Granted we are all in the VHF side and most folks run a quarter wave to eliminate then eed to tune to a certain frequency. 

I laugh at all the complaints on here about loosing linking. If that's the only reason you use GMRS you need another hobby. As has been said many times over and over GMRS was never intended to be a social gathering place. It was meant for local communications for families and friends. All linking has done is ruin this in many areas. Use GMRS for what it was intended and its fine. I operate 6+ repeaters. I've never needed nor wanted any linking. Each one is for a purpose. If I need to chat with someone 100 miles away I pick up the cell phone. Personally I hope this is the start by the FCC to do something. Maybe they will, maybe they wont. But if those that are linking decide they dont want to deal with it and dropped there links its up to them as the owners of the equipment. To many folks get on hear and complain about the way a repeater works, covers or operates. There is also the expectation that repeaters are up for you and your family. If you didn't purchase it, install and maintain it then you need to rethink. 

Not sure what kind of radio you showed Steve, but here are repeater settings for my stuff - 
GR1225 Calls it Hang Time

MTR2000 Calls it Drop out Delay

Icom Calls it Hang Time

I dont have my Quantar or GTR8000 software on my home PC so can't show those. 
 
 
 
 

Not sure what kind of radio you showed Steve, but here are repeater settings for my stuff - 
GR1225 Calls it Hang Time

MTR2000 Calls it Drop out Delay

Icom Calls it Hang Time

I dont have my Quantar or GTR8000 software on my home PC so can't show those. 
 
 
 
 

It was alwasy common to test in the middle when we used CB and think GMRS would be the same. With that said repeaters are 467.xxx and simplex is 462. If you use simplex 99% of the time I'd test on a middle 462.xxx channel. For instance a 1/4 wave should work fine across the board. It realyl depends on useage. For my SAR stuff we always use the National SAR channel for tunign as thats the most important channel we use. Other channels are repeaters and a portable works fine so worring about a great single from the mobile is less concerning. Granted we are all in the VHF side and most folks run a quarter wave to eliminate then eed to tune to a certain frequency. 

Your feelings do not matter.
I have setup in the neighborhood of 30 repeaters from the listing here, and 100% of them had all the information I needed to use them.  If you are not able to figure out how to use a repeater listed here, then you are doing it wrong.
and no, those details will not benefit the community at all because they are irrelevant, or in the case of tones, all the info is already there.

You miss understand public spectrum. Spectrum is the frequency and airwaves. Equipment I purchase, install, maintain is my personal equipment. If someone requires membership its up to them. Personally my repeaters are closed. I see no need to pay for power, tower fees and other associated fees for others to use it. GMRS is not ham radio. Sadly many feel if they buy a $35 license they are entitled to use any repeater they want. 

Have used GMRS for over 3 decades. Alwasy used as a family communications system. Few years back started using it for some off road events. Now its either GMRS or CB for all the off road events I go to. Still use it primarily for private communications. Not to sound rude but if someone was on my repeater thant not my user I wont answer answer them and neither will my users. Thats my decision. In a disaster I doubt GMRs would be much use no matter how many claim it will be.
 

I laugh at all the complaints on here about loosing linking. If that's the only reason you use GMRS you need another hobby. As has been said many times over and over GMRS was never intended to be a social gathering place. It was meant for local communications for families and friends. All linking has done is ruin this in many areas. Use GMRS for what it was intended and its fine. I operate 6+ repeaters. I've never needed nor wanted any linking. Each one is for a purpose. If I need to chat with someone 100 miles away I pick up the cell phone. Personally I hope this is the start by the FCC to do something. Maybe they will, maybe they wont. But if those that are linking decide they dont want to deal with it and dropped there links its up to them as the owners of the equipment. To many folks get on hear and complain about the way a repeater works, covers or operates. There is also the expectation that repeaters are up for you and your family. If you didn't purchase it, install and maintain it then you need to rethink. 

I laugh at all the complaints on here about loosing linking. If that's the only reason you use GMRS you need another hobby. As has been said many times over and over GMRS was never intended to be a social gathering place. It was meant for local communications for families and friends. All linking has done is ruin this in many areas. Use GMRS for what it was intended and its fine. I operate 6+ repeaters. I've never needed nor wanted any linking. Each one is for a purpose. If I need to chat with someone 100 miles away I pick up the cell phone. Personally I hope this is the start by the FCC to do something. Maybe they will, maybe they wont. But if those that are linking decide they dont want to deal with it and dropped there links its up to them as the owners of the equipment. To many folks get on hear and complain about the way a repeater works, covers or operates. There is also the expectation that repeaters are up for you and your family. If you didn't purchase it, install and maintain it then you need to rethink. 

"Take a look at the Motorola XPR "e" series and the Vertex EVX radios if you want to see what a SDR chip coupled with good electronics and a little filtering can look like. Heck, even the older CDM mobiles had great analog receivers with some nice audio."
 
Why I use CDM 1550LS+ (surplus from previous employer) and a XPR7550e for GMRS use now. Great radios that do what I need them to do. And will most likely last for years doing so. 
Better equipment, and paying attention to detail on coax and antenna means better signal quality, less power loss and more reliable use. 

No, there are posts in this thread from 2018 that include quotes of the rules which clearly show that the phrase “any other networks” existed years ago.