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Since you already own the duplexer and have it tuned, you can still use it on the receiver side by putting dummy load on the HIGH side. It should improve the receiver's performance.

Well, that's very kind of you. I can do with positive thoughts!

I've read every pixel there and see no link to a "VIP" section. I've generated a ticket to see what's up.

Two comments: There is a V/M button which means there is a VFO. Programming from the keypad makes it ineligible for Part 95e centification. I'm constantly amused when the Chinese call these mobile units "walkie-talkies" in their eBay listings and/or digital ads.

GMRS license is now $70 for 10 years. I just had to renew mine a few weeks ago. This will probably outlast me since I'm 73 years old now... My ham license will expire in 2028, so I may have to renew it though...

As long as no "price" or discussion of "price" is made, 'tailgate nets' are certainly allowable.

Back in the 80's I charged $8/foot for a climb plus any hardware I supplied. I carried a $2 million dollar liability policy.

I haven't visited there since 2019, but apparently all of the Motorola CPS files have been removed...

Not mentioned yet, but you cannot use a "CB" meter for a UHF radio!

Absolutely you will notice a huge difference, especially on the receive frequency. You will still have some power loss, but by having the duplexer tuned to precisely your transmit frequency, it will be far less loss. Here is a screen shot of a tuned Bp/Br duplexer (band pass/band reject). Note that the upper red line is the "reject" trace. It has a 5MHz skirt and is rejecting the transmit frequency from the low side, and the receive frequency from the high side. This is from a 70cm duplexer. Here is a blog illustrating how to "sort of" tune a duplexer with a NanoVNA: http://wa8rra.org/duplexer-tuning/ Here is an excellent video showing the major weaknesses of NanoVNA versus a professional Textronix unit. https://www.youtube.com/watch?v=GipCVEsiqXc

Your duplexer is mis-tuned! It should be tuned to precisely the frequencies you are going to be using. The entire purpose of the duplexer is to allow only a single frequency to pass with minimum loss, while supressing any other frequencies. The easiest way to explain this is with a picture. This image is from a VHF duplexer, but the principles are the same. Note that the green line represents the lower frequency of your pair and the red line represents the higher frequency. It is important to note that any frequency lower or higher than the tuned frequency is quickly attenuated. This is precisely why you are losing so much power when you transmit:

Scott, I could not agree more! Unless you have the $$$'s to rent space on a tall tower (200' or more), then it is an exercise in futility.

No true "skip" but there is the occasional tropospheric ducting occuring. See: http://www.dxinfocentre.com/tropo.html for the weekly forcast.

You first made a claim that DMR is permitted on GMRS frequencies. The answer is still no, it is not permitted. Some limited form of digital data is allowed however, that much is accurate. Of course DMR will work on GMRS frequencies, but it is not legal. I agree that it would be nice, but not practical because of the sheer number of legacy analog systems already in use.

I have five DMR HT's from various manufacturers all of which work analog GMRS just fine. I also have four mobile DMR transceivers that will do analog GMRS as well as the intended amateur DMR VHF and UHF. Motorola XPR7550 UHF Anytone 868UV Ailunce HD-1 (U/V) Radioddity GD-77 (U/V) TYT MD-2017 Motorola XPR5550 UHF 2x Connect Systems CS800 UHF Connect Systems CS800D U/V

DMR is still not allowed. SMS and GPS position are transmitted via analog FM. DMR uses narrow-band versus GMRS remains primarily wide-band.

How far away is the receiving radio? You are probably de-sensing the receiver's front end...

Yes the placement of the antenna will affect the "ground plane" which in this case is your vehicle, and have a major lobe as you described for a CB antenna. This is why the center of the roof is recommended for best coverage.

The sole exception to the "no kerchunking rule" does not affect GMRS at all, but does affect all DMR repeaters. Most of the hundreds of Talk Groups are "PTT" only, meaning that to activate them on one's local repeater requires a very brief PTT, pause and listen to make sure no one is already having a contact, then giving your call sign.

There are as mentioned previously many such places, including the flagship ARRL website http://arrl.org They are using the actual question pool from which the questions will be asked. The FCC places a great deal of trust in the integrity of the volunteer examiners, which frankly is truly remarkable. Back in the ancient days my dad and I had to drive from Ft Myers, FL down to the Miami FCC Field Office to take our tests. Because of the distance, we had to sit for all of the Elements for everything up to General Class, plus the code test. It was an exhausting but rewarding day!

Thanks for the update. Apparently he expanded the allowed frequency ranges. It used to allow no higher than 450 MHz.

It was a Bridgecom BCR-40U https://www.bridgecomsystems.com/products/bcr-40u

Back in the old days when the PL-259 and SO-239 were invented, what we now call VHF was imagined to be UHF!

There is a service listed on eBay who sell a legitimate FPP firmware/CPS package for XPR radios. IIRC it is $299 USD.

No worries. I actually wound up buying a XPR5550 the other day from an eBay auction. At $300 I think it was a good buy... ...although for the life of me I haven't a clue what I'll wind up doing with it! I may wind up using in here in my office and move the current CS800 into the kitchen. That means another antenna and feedline of course.