BoxCar

Probably the best way to characterize the Midland antennas is they are "peaky." That means they don't have a smooth SWR across their stated bandwidths.

Some of the better antennas for just GMRS are those by Laird. The quarter wave ones are about six inches in length. There are several manufacturers of good antennas that do both VHF and UHF. I use a https://www.talleycom.com/viewProduct?rlProdNum=ANXA450&utm_source=octopart&utm_medium=url&utm_campaign=laid-feed

As to which coax, look them both up and note the loss figures. Calculate the length needed to go from you antenna to your radio and then apply the loss figures. Simple math, but you want the cable with the least loss as it means more power to the antenna. For the most part, you can ignore the connectors and their loss.

As a follow-up, you need radios you can field program as well. Whomever is acting as your communications coordinator needs to have the software to program the radios and a chart listing which channels are to be used. Those operating on FRS only need the GMRS channels disabled while those having licenses need to know what GMRS channels are used as well as the FRS. If you are using MURS, then the channel usage charts are easier with one channel for group, one for trail bosses.

I just checked this one: https://consumercomplaints.fcc.gov/hc/en-us

Perhaps a better idea of a "fixed" station would be one station connected to a sensor that when tripped radios a signal to another station to flip a switch on or off.

And your electric energy source is????

The best answer is depends. Higher power doesn't always mean better coverage/distance. One of the biggest problems with FRS is the antenna on the individual radio. You can't change it to use a better/longer one. The radio and its antenna are fixed by FCC rule. Your better choice is GMRS radios with mag mount antennas. Those not licensed for GMRS would be restricted to the FRS channels. Their using GMRS capable radios is a grey area because GMRS radios do have more output power on FRS channels and removeable antennas. The other option is MURS, a VHF service limited to 2W but because its lower frequency it will have a marginally better range than the UHF GMRS/FRS units.

Thanks for the correction. However, the documentation provided by Midland on this radio state everything is preprogrammed with no mention of the ability to modify the factory presets.

While the Midlands are a good solid radio, they are not fully compatible with most GMRS radios. The Midland MXT400 is a narrow band radio meaning the signal from the radio is roughly half of what wide band radios have. This does not have a significant affect on the radio's range but it does affect the intelligibility of the voice signal. GMRS is a wide band system with the companion, Family Radio Service is narrowband. There are other brands of radios designed for GMRS/FRS service that can operate both wideband on GMRS and narrow on FRS. The current MXT400 cannot do this. There are reports Midland will correct this in a new versio of the MXT400 sometime this fall/winter.

Another example, and probably easier to understand for the general public is a Microwave that only talks to a single distant point.

Yes, a truckload would also get their attention.

Use a weighted line and toss it over a tree branch. use the line to pull the antenna vertical, no need for poles or tripods.

You're right. The protesters filed a complaint with the FCC about interrupting the cellular network. The Association I was with filed in support of the MUNI stating it wasn't a public network that was shut down. MUNI had installed an inbuilding repeater network that carried the cell carriers. They shut down their system which did not affect the service normally available from the commercial services. The FCC agreed, MUNI could turn their system off at any time.

The San Francisco Bay area had several protests about 10 years ago when the fares were raised on their subway system that were organized and coordinated using text messages between cell phones.

Business, or B/ILT frequencies are all shared with few exceptions. There aren't many using trunked radios which do require exclusive use of channels in an area. The distribution of available frequencies among the many different coordinators is also an issue. All coordinators have their fees but there is an additional inter-coordinator fee charged if you go through one coordinator and the only channel they can find is assigned to another. That means the frequency is coordinated twice. The licensing coordinator and the consenting coordinator both have to agree on the channel selection. Also, certain channels that may show as available in a frequency search by a dealer may be reserved by the coordinator for a particular use such as a specific class or type of business. Each coordinator sets their own fees to the customer so coordinator shopping is worthwhile. When I left the business there were two public safety coordinators that had agreements with business coordinators allowing them to assign both 90.20 and 90.35 frequencies. APCO was the only PS coordinator that couldn't handle business frequencies in house.

Marc, You may want to check when that mall's license was first issued. It's entirely possible the original grant was a B/ILT and grandfathered in when the band was reallocated to unlicensed.

The MURS channels originally were common business/construction frequencies. Many of our dealers will tell you they had hundreds of radios on the colored dot frequencies. One company I worked for had a bunch of "red dot" handy-talkies.

As you point out, anything between an antenna's radiating elements and open air does affect the efficiency of the antenna. Metal pipes and ducts have a greater role in they can create RF shadows or even act as a parasitic radiator that either opposes the intended pattern or will add to the pattern creating an unintended lobe. It's these extra elements that are used to create directional Yagi antennas that shape the radiation pattern and "steer" it into a focused beam.

Marc, I'm a technical type myself and I did pick up on the misstatements but I also wasn't going to nit-pick a great analogy apart over what, in the great scheme of things, were fairly minor points. It was, and still is, a great non-technical write-up of a very technical topic.

There are several conversations (threads) regarding the Midland MXT400 and getting it to talk with other radios. One of the first items will be learning what you have factory programmed in the radio. Some of our Midland specialists will be able to help you better.

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,

Same process, different meter.

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.

FRS does not require identification.