BoxCar

Your interpretation is in error. If a radio is type accepted to operate under one section of the regulations then modifying the radio to operate under a different section of the regulations invalidates the original type acceptance because the radio was not tested under the second set of requirements. It doesn't matter if the modification involved hardware and/or software. Any modification that causes the unit to operate outside its accepted parameters requires the radio to be resubmitted for type acceptance. The FCC Rules and Regulations require 7 volumes to contain them all. Reading one portion of one paragraph under one section does not negate the information or requirements found in the entire body of Title 47 of the US Code.

You need the one with a matching connector. The connectors are typically a male or female SMA or BNC. The Yeasu uses the female SMA.

No, the rule states THROUGH a repeater system. Units are limited to test transmissions only otherwise. Using an input frequency for simplex communications is not permitted.

The BTECH UV-25X and 50X also do them. I have a 25X2 that I use on 2M and 70CM.

I have found more hams monitoring/working the local repeaters than the calling frequencies. I did a trip from Asheville to Shreveport and found the activity was almost always centered around the 2M repeaters. I used Repeater Book to find the local repeaters along the route I traveled.

Repeaters require "high site" locations. High site means mountain top, highest building or tallest tower in the area. On mountain tops, lower gain antennas work better as they are more omnidirectional. As the gain goes up, the antenna pattern starts to resemble a donut more than a slightly squished ball. This increases the radiation pattern more to the horizon rather than filling gaps nearer the antenna. That said, an omni rather than a beam type antenna is what you are looking for. There are several designs that meet this requirement from vertical whip types to vertical poles with multiple folded dipole antennas attached. Your wallet will be a big deciding factor on which antenna you install.

What I predict is we will see units that will automatically mode switch between AM and FM based on the signal being received. We will also see dual receiver units, one AM, the other FM and the transmitter will shift mode depending on which receiver is selected.

The place with the helpful hardware folks sells small sheets of sheet steel. I picked up a piece 2' x2' for less than $15 there.

There is very little to stop the change from being published. The rule change has to be vetted by administrative agencies for finance and paperwork impacts and then scheduled for pub by the Government Printing Office on an almost space-available basis. Routine red-tape delays.

The changes have to be published in the Federal Register first. They will then be effective 30 calendar days later. It can take more than 2 months for the publishing.

The RG-8X cable cuts the power being fed to your antenna by half for the 50-foot length in use. The gain of the antenna makes up for the losses in the cable so the result is you are even power wise. From the info you have provided though, it appears you don't have any test equipment. The best place to start will be with a SWR/Power meter for UHF measurements. I would add to that a dummy load handling 50W at a minimum. The dummy load will provide a known value so you can see how well the SWR/Power meter is calibrated. Both items are available from radio shops selling radios and Amazon. While not a recommendation, many people use UHF meters from Surecom that provide the transmit frequency, power being sent, the amount of power reflected back because of impedance mismatch and the percent of power being fed to the antenna. These will tell you how well your antenna and/or radio is performing.

A Yagi is probably your best chance for reliable communications but the one taco6513 is suggesting is 6 feet long. The Browning BR-6356B is 42" and $80 less with close to the same gain.

You may try slitting the weatherstripping and then sealing the slit with some Gorilla Glue or silicone glue.

I would guess the mounting location is the problem. The 32 inch antenna places it above where it is shielded by the vehichle.

Antennas often use the shielding of the coax as part of their ground or counter-poise. It's possible you trimmed too much and affected the loading of the antenna. Assuming it's not a bad connector, an antenna analyzer (vector network analyzer) would answer the question. VNAs can be found on Amazon. I recommend one with the large screen for better clarity.

For the most part, coiling cable has no affect. There are exceptions in that a tightly coiled cable can act as a chock or a balun and change the impedance to the antenna. But then we are talking TIGHT coils less than 3 inches in diameter. Loose coils, about a foot or so are not a problem and they can even be squished down so the coil is more oval or even egg shaped with no issues. Kinks are a different matter altogether as they affect the impedance of the cable at the point of compression. For an SWR meter, there are a great many choices, with the Surecomm units being fairly decent. Dummy loads are rated in watts as to the amount of power they will handle and are also available from many sources. I have an MFJ unit that will handle up to 300W for about 6 seconds and pretty much laugh off 50 w from the typical mobile. The dummy load takes the place of the antenna so the SWR/power meter goes between the transmitter and the load to measure power. Connect an antenna in place of the dummy load and you can read the amount of power reflected back from an antenna to your radio. The lower amount of reflected power the better.

To my knowledge the FCC has never tracked if a licensee continues to use a frequency after their authorization expired. It's usually brought to their attention by someone who wants the frequency, or the operator is causing interference to other licensed users. In the case of the mall, you are a licensed user so report the mall as causing harmful interference to your use of the frequency. The FCC will start with one or two actions, either by sending an agent or by letter. In either case once the ball starts rolling it won't stop. Do your part and file a complaint. Granted it won't be a high priority for the Commission but they will take action especially if you can get other GMRS users in your area to also file.

Should be more than a 1/4 wave or a multiple if less than70 CM (about 2 feet)

The FCC has a program for towers etc. TOWAIR on their website;

It's because they think theirs is more round than yours. It's the NIH syndrome -Not Invented Here.

The FCC has rules regarding antennas and their structure. If an antenna is not more than 20 feet above its supporting structure (chimney, tree water tower etc.) it's under the 6.2 meter rule. Antennas mounted to structures more than 20 feet in height should be registered. Antennas that are more than 200 feet above ground level (and that' the entire antenna to the tip) have to meet FAA requirements for lighting . As MacJack also stated, if you are within 5 miles of an airport there are additional rules that have to be followed.

There is no circulation so the heat can't exhaust. Heat is one of the largest enemies of radio performance and longevity.

There is little difference in performance between the Laird phantom and their 1/4 wave wire stub. Actually, the wire stub is less noticeable than a black or white phantom on say a red car.

Gain in a low profile antenna doesn't buy much as the key to any communications in the UHF range is antenna height. I have a Laird 1/4 wave wire stub at unity gain and it is virtually the same as what you are proposing. The key to understanding gain figures for antennas is to know what the gain figure represents. If it's in dBi. subtract 2.15 from the number to get it's true gain in dBd which is the amount of gain you get on a real antenna. So an antenna with a 2.5 dBi gain has .35 dBd more output than a 1/4 wave stub.