WRXB215

One simplex controller:
https://www.argentdata.com/catalog/product_info.php?products_id=98
 
Reviews on EHam.net:
https://www.eham.net/reviews/view-product?id=7625
 

@WRYQ685 & @WRYQ274, Welcome, this is a great place to be to discuss two-way radios.

Congrats on your new purchases.  Keep in mind those HT's (GXT1000VP4) are not repeater-capable, only simplex communications (and their range is vastly overstated).  However the MXT575 will have no problem with repeaters, just get a good antenna for it (either base or mobile, however you plan to use it).

Good Afternoon,  Tomorrow I will be receiving the Midland GXT1000VP4 (3-pack walkie-talkies) and then next week the Midland MXT575 MicroMobile arrives.  Hopefully I find this equipment useful for the family commuting and communicating around Oahu.
My next project will be investing in a GMRS repeater of some sort in the Wahiawa Heights area.
Hoping to meet enthusiastic folks in the near future,
Cheers
685
 

You know what's weird? I'll tell you what's weird. Thanks for asking. There was a time when CB radio was supposed to be for short range comms. Then DXers got hold of it to see how far they could talk. Like amateur radio. Then along comes GMRS. It was supposed to be for short-range comms. Then DXers got hold of it and and linked their repeaters so they can talk all over the country. Like amateur radio. With all the amateur radio bashing that goes on here, why do so many people want GMRS to be like amateur radio? 

Yup, with a home brew J-Pole & two stainless steel clams…. Works great and not even grounded

Yeah! Don't be so "standoffish!" 🤣
Sorry for the bad joke, I couldn't resist.  😉

Hey! I resemble that remark!

@WRQC527 I'm out of reactions but as soon as the time elapses, I'm going to like that post. 👍

Many of us need some help sometimes.  I’m no different.  I got started with GMRS quite a while ago (but unlicensed), but I really became interested after watching your videos.  If I can pay it forward I will.

What exactly is your issue?  UncleYoda posted a screenshot that we can use to answer specific questions. 
If you ask us specifics we can try to give specific answers. 
To begin, what are the requirements for the repeater you want to use?
 

So, you hear nothing while transmitting and then, when you let go of the PTT, you hear a burst of noise? (Squelch tail)
Are you testing by transmitting on one of the radios while the other is close nearby so you can hear it?
Transmitting on one while listening on another that’s close by can cause something called “desense”.  What happens is that the listening radio goes deaf to the repeater because it’s overwhelmed by the RF power of the nearby transmitter. 
Try giving the receiving radio to someone at the other end of the house (or even further).

That’s what generally foils the whole idea not to mention repeaters, including cross-band types, are prohibited in MURS.
A variation of the cross-band idea is an in-band spilt frequency operation. Many radios can be programmed to receive on one frequency and transmit on another within the same band using an arbitrarily frequency offset.
The idea would require the GMRS user to transmit on a legal GMRS frequency and receive on a frequency in the Ham 70cm band. 
The Ham radio user would then transmit on a legal 70cm simplex frequency, which is programmed into the above GMRS radio for receive only, and receive on the GMRS transmit frequency programmed in the GMRS radio.
Nether radio requires modifications nor dual band operation. Just the ability to program in spilt UHF frequencies with an arbitrarily offset.
This operation in not legal either for the prior mentioned rules. The Ham station shall only contact other stations in the Amateur service. Also it could fall under the general prohibition to engage in one-way communications since the other station is NOT in the Amateur service. 

I wanted to point this scenario out before somebody dreams this case up and tries a convoluted argument this would pass under the rules. It won’t. 

It's a free country. If you don't want to listen to linked repeaters, then you do not. If you want to listen to rag chews and join in, then you do. Ride your own bike and let others decide what do they want.
 

Look at masts at DXEngineering.com. 
If you were only going 10 feet I would look at top rail for chain link fence. It’s available up to 20 feet long. 
However, if you have a rotator you really need to stay under the weight limit of your thrust bearing. I don’t have any idea what that is. You might be back to your stand-off idea. You too could end up with a tower like this: 

Yeah! Don't be so "standoffish!" 🤣
Sorry for the bad joke, I couldn't resist.  😉

Why don’t you answer?

As a Ham you’re limited to ONLY making contact with other stations which are licensed and operating in the amateur service of the US, or of the country the station is located in. Obviously GMRS is NOT a Part 97 service. As a Ham you should know this. I would recommend you get a copy of Part 97 rules and throughly read it. It’s pointless to waste time on something you can easy research yourself.

The reason it’s done is the elimination of the heavy, bulky and expensive cavity filters required for an in-band repeater. This applies to analog radios.
The filters are required because the RX and TX frequencies are close together. Without sufficient isolation the transmitter will overload the receiver such that it effectively become deaf. Remember the receiver is feeding every it hears to the transmitter at the same time.
A cross-band repeater the frequencies are space far enough apart that a far simpler and cheaper filter can provide the isolated required.

No, it isn’t. For a 50 watt radio you would probably need at least a 15 amp power supply. 

https://chirp.danplanet.com/projects/chirp/wiki/MemoryEditorColumns
Read up on tone mode. This really helped me.

Yeah! Don't be so "standoffish!" 🤣
Sorry for the bad joke, I couldn't resist.  😉

https://chirp.danplanet.com/projects/chirp/wiki/MemoryEditorColumns
Read up on tone mode. This really helped me.

You can build a better antenna than any commercially manufactured one if you are handy. Search for homebrew ham antennas, and use a calculator to resize the elements for your preferred frequency.
https://www.hamuniverse.com/wb3aywcollinear.html
I built a 4-element collinear vertical antenna from copper tubing. It took a bit of tuning to get it perfect, but it was worth the effort. Total cost was about $60, and antenna gain is about 7 dBd (9 dBi). The difference between that and my dipole is amazing.

Try snipping a little bit off the end of your antenna and see if that helps. Really though, have you tested to see if your HH isn't being desensed by the repeater?