BoxCar

I also think the issue is tones. You need to be certain the tones are the same. Privacy codes are set by the manufacturer and may not be the same transmitted code. There are 50 different tones used for squelch quieting so code 2 may not be the same from manufacturer to manufacturer.

Ignition noise

Get the make and model of the Harbor Freight charger noting if it reports it meets FCC approval. Report this information, including photos of the packaging listing FCC certification to the FCC. Pictures of the charger assembly showing a label listing the model information and any certification logos including the country of manufacture. This is the type of report the FCC will investigate. It may end with a citation to Harbor Freight but little else for existing equipment.

There are several releases of fines against companies for selling noncertified radios and equipment. There are also reports of individuals being cited and fined for use of illegal transmitters causing interference to other services. While I haven't been active in radio licensing for several years there are multiple reports of CB shops and truck stops selling noncertified equipment, primarily 10 meter and uncertified CB gear. The reports for individuals are primarily for using jammers affecting airport radars, public safety and cellular communication. Hobby King was fined over a million for selling noncertified RC transmitters.

I think a lot of the changes in Part 90 radio is being driven by First Net. We aren't seeing big wholesale system replacements/upgrades from a lot of agencies with the advent of push-to-talk on FN devices. PTT and multicast were always the biggest advantages to radio but most of the comms was still one-to-one. The alert broadcast is being replaced with a text type message sent to a data terminal device either in a vehicle or handheld terminal/communicator. PTT radio is falling into a secondary use rather than being the prime communications device it has been for almost 100 years.

Yes, it's possible for the radio to be putting out higher power. Most are designed so their power is reduced to the advertised level and the heat produced is lowered. We used to "crank up" the finals in our CBs back in the 70's to as high as 12 to 15W on AM.

A control station IS NOT a fixed station. A very good example of a fixed station is a microwave link. It only communicates with another fixed station and no mobiles. Other examples are sprinkler control stations used for irrigation, flood control monitors, or other stations used for datalinks.

Well, yes and no on repeaters and channels. In GMRS there are channels set aside for repeater operation however it is not true that only repeaters may operate on these channels. FRS (and GMRS) can operate simplex (using the same frequency to transmit and receive) on the output frequency of a repeater pair. In the amateur world the channels are a little more structured in there are ranges for repeater channels and these are coordinated by regional volunteers to limit interference. In the part 90 world, the only band with repeater frequencies specifically limited is in the UHF spectrum but the LMR coordinators will and do assign repeater frequencies in any part of their spectrum they can.

A 102" antenna is about 4 wavelengths at 464.5 MHz.

A lot of regulations are boilerplate at the FCC needing only a few words to be changed along with the section number. I doubt the FCC figured anyone would set up a fixed station using GMRS repeater channels but, just in case, they threw in the limits.

Have you done a comparison of the 7100 to the 7300 and the 991A?

Not knowing about the Pi setup, are you certain you are receiving the high frequency and transmitting on the low frequency. These can be tested inidividually.

Currently there is no charge for an amateur license.

The best receiver won't do anything if there isn't enough power in the transmission to activate it. It take all three, power, sensitivity and an effective radiator.

Get a used Part 90 Moto repeater and run it at no more than 75% of its rated power with an antenna mounted as high as possible.

Your problem is not the radio as much as the antenna (or lack of one). The only way you are going to get that range is by using an antenna mounted to the highest point on the vehicles.

Check out the information at www.repeaterbuilder.com. It will go a long way to answering any questions you may have, but the first question you need to answer is what do you intend for your repeater? Will it be a local resource for family and friends or will it be for general use? What, and how much area do you want to cover? Finally, are you ready to spend between $300 and $2000 for a repeater?

The difference (offset) for GMRS is 5 MHz. The repeater receives its input signal at 467 MHz and transmits at 462 MHz. Tones can be added to the repeater to limit access. You would add tones to the repeater's input frequencies and the same tones to your personal units output frequency, So, the repeater setup is opposite what you set up for your personal units. Your personal units will transmit (with tone) on the 467 frequency and listen on the 462 frequency.

Here's some other options: Amazon.com: Wishring Re-02 Mobile Antenna Ground Uhf-f 10-1300mhz for Car Radio Motorola Icom : Electronics Amazon.com: TRAM(R) 1192 Pre-Tuned 150-154 VHF / 450-470 MHz UHF Dual-Band Land Mobile Glass Mount Antenna, Black : Electronics

OffroaderX has detailed the differences between the radios so he choice is yours. Personally, I would not use the Midlands as GMRS sparked me going into ham radio and my GMRS radio gave me the ability to explore what was available locally on the ham VHF and UHF channels. If you think there is the possibility you would want to go farther, then the choice is pretty clear. The limitations of the Midland radios will also come forward if you plan on doing some traveling.

I'm going to use a Tram 1191 on the left rear window of my Discovery to work both VHF and UHF frequencies.

State personnel use state frequencies and feds use federal ones.

You're not too old! The Tech test is easy and opens the 2M 144 MHz and 70cm 440 bands for use. I passed the test easily with a little study at 76 years of age.

As stated, there are no base station radios for GMRS. It would be a useful product if someone built one with a decent front end that worked off AC. The repeater channels could be hard coded with an easy access menu to add tones as required. The remaining channels are simplex and the FRS channels could be receive only as FRS requires a permanently attached antenna. The FRS antenna could be built into the case much like a cell phone though.

It depends. The repeater antenna is probably on a high site so it covers the largest area. Your antenna must be in a spot where it would be in line-of-sight of the repeater antenna and not blocked by large buildings or trees. If the terrain between the repeater and Castle Rock is blocked by hills, mountains or whatever a 1000W radio probably wouldn't get through.