Lscott

That was a long time ago. The younger electrical engineers walk into my office and sometimes ask what that funny looking ruler thingy is hanging on the wall above my desk. And they don’t know what a vacuum tube is either. Sad. https://forums.mygmrs.com/gallery/image/342-slide-rulejpg/?context=new

I tried using CHIRP on a Kenwood TK-370G radio, 128 channels with zones. CHIRP messed up the code plug by screwing up the entered frequencies and switched them between zones at random. I gave up and used the official software which is Windows based. Then there is the Kenwood TK-370, 32 channels and no zones. Seems to work OK for that. I 'll use CHIRP since the only official software for that radio is DOS based. There is no windows version.

This is why all my "GMRS radios" are really commercial grade LMR's models programmed to GMRS frequencies. I use the manufactures software whereas possible to do the programming since it allows access to all the radio's options. I've tried to use CHIRP on several radios. Unless it's a VERY basic simple type I've had CHIRP mess up the code plug a few times and went back to the manufactures software. I tend NOT to use CHIRP unless the manufactures software is a complete POS, or not avaialble.

You need a bigger battery backup system. PowerSafe GC-M Specs.pdf

So many forget this point. I see many radio clubs building emergency communication trucks filled with radios. The owners manual for them is 100’s of pages long to cover all of the options and settings only accessible through multiple layers of menus. Expecting volunteers to figure out how to operate them under the stress of a real emergency is just going to contribute to the disaster. You need brain dead super simple radios to operate in these conditions.

What version of the firmware is loaded on the radio? Hopefully it’s not the Passport one.

So, that means clearly the POTS, plain old telephone system, network. In that context then linking through other kinds of networks, Internet, would be OK. That implies linking GMRS repeaters through other kinds of networks should he just fine.

Hum... I wonder if linking repeaters, more than two, over an RF link, could be considered a "network." It seems the real question is the very definition of what is a "network" in the context of the FCC's usage. With a firm mutually agreed upon definition the rest should just fall into place.

The non display models I have are a few Kenwood radios. A sample is here: https://forums.mygmrs.com/gallery/image/291-tk-d340u-front-and-back-2jpg/?context=new I have to print out a cheat sheet to remember what each channel is programmed to.

That was the model I saw being recommended. I have some non display Kenwood radio models in my collection. Nice radios but not very convenient use. With up to 32 channels on some of them trying to remember what channel is programmed for what isn't easy if you don't use it very regularly. That's why my preference are the display models.

The attached paper was published in an engineering journal. It goes a bit more into the details of narrow verses wide band FM. The material isn't for the "casual" reader. Narrowband vs Wideband.pdf

Not specifically, but I think it was Amazon.

A buddy got one the other day. He said he still needed to install the software to program the radio. He did comment about the funky stud type antenna port.

Oh, if you want to find out what is on the various frequencies using the main digital modes, DMR - P25 - NXDN, this site linked below is a good source. https://digitalfrequencysearch.com/index.php

Now days most of the public safety stuff has moved to 700/800 MHz and typical is digital, P25, and maybe using encryption. You may find a few cities that have remained on 450 to 470 MHz narrow FM. There is a lot less to monitor. I have seen some movement where legislation is being proposed to at least prohibit encryption on the public safety frequencies. That's likely to go nowhere.

Those people were lucky. Several posts in other forum sites users reported noticeable reduction in range. I guess it all depended on the original system design before the changes.

Thanks. I found some info on those now that I have a name for it. https://www.motorolasolutions.com/content/dam/msi/docs/en-xw/static_files/Related_-_Vibrasender_and_Vibrasponder_devices.pdf

Antennas are symmetrical devices. They receive about the same as they transmit.

Yup. You "race" away as fast as you can from the black squirrel with the white strip on its back, not towards it.

Using a high gain antenna the radiation pattern tends to be flat like a pancake. This concentrates most of the power out horizontally at a 90 degree angle to the antenna. What I suspect is happening is most of the RF power is simply shooting over their heads or hitting the canyon walls. The HT antenna radiation pattern is more like a fat donut. A lot of the power is at much higher and lower angles relative to the 90 degree position. This allows you to get a signal to and from other stations at much different horizontal elevations. What some people do is carry several antennas then swap them out depending on local terrain. A high gain antenna is great for open flat country. A low gain, typically a 1/4 wave like what is commonly found on HT's, when in hilly or mountainous areas.

It doesn't really serve a useful purpose in GMRS without the special equipment, but does identify one as a Motorola radio user much like the white strip down the back of a sunk.

That's likely true. Myself I don't know of any. Those repeater owners that use MDC1200 tend to get labeled as Motorola snobs since that company originally had the patent on the signaling method. It mostly limited the repeater access to users with Motorola radios.

If the squelch tone was sent continuously during the transmission, reed stays sync'd, by inverting the signal at the end would generate a 180 phase shift bucking the original one. How it's done now I don't know. Everything is done by micro's now with the magic in the software.