JLeikhim

My read is that TPO is where the transmitting equipment meets the feed line. If transmitting equipment includes harmonic filter, circulator and a duplexer,, so be it, no problem. As long as the TPO is 50 watts. The Motorola MSF5000 station integrated all of those optional components making a 100 watt station deliver 75 at the connector on the cabinet. This confused technicians who would see that the station was spec d at 100 watts without those internal options, and so they would turn the power up to squeeze 100 watts from the cabinet and that would make the PA run much harder. Sent from my SM-T350 using Tapatalk

True, they would work far much less sucky on the moon or way out in the boondocks. In fact, Midland backs up their 32 mile claim for their GMRS radios by testing them line of sight from a huge hill way out in some wide open rural area. The lawyers are happy, but folks who now have those radios, question the claim when they barely get a half mile in a suburban area. I have some ICOM IC4008A FRS radios that are superhet, but very basic design with little preselector filtering, just a simple coil. Better than an SOC design. They work very well out in the National Parks. But around town, not so much. I keep them because they are easy to use and the AA batteries last days when camping. My wife and son carry them because they are small. A radio is a tool like anything else. A battery operated drill from China sold at Harbor Freight might get by for the casual home user. But I have a Japanese Makita drill I purchased in 1980 for $300 in 1980 dollars , that has outlasted all of the cheap drills I bought in the meantime. For $35 You are not getting much of a drill. Same for cheap radios. Sent from my SM-T350 using Tapatalk

Cheap receivers that lose all sensitivity in urban environments. Radio works fine out in the sticks, but if you get near a bunch of tranmitter towers or downtown with many transmitters, they lose sensitivity. Hearing police transmissions at VHF in the FRS GMRS band, NOAA weather blasting Intermod. That is the real world, versus hooking a signal generator up to the radio on a bench and reporting it has a terrific -122 dBm SINAD sensitivity. Real world is many signals some hotter than -40 dBM entering the receiver chip. Also sucky are cheap radios that have very scratchy clicky picket fence noise while in motion. They lack an effective FM limiter that would normally supress the AM components of a multipath condition. Read the complaints. Sent from my SM-T350 using Tapatalk

Most of the cost of a radio goes into receiver design. All manufacturers must meet minimum FCC specs for the transmitter, so that cost is fixed. Cheap radios will have simple receivers. SOC, System on a chip receivers have a minimalistic design controlled by software commands. The main thing lacking in these designs is RF preselection . The other problem appears to be the lack of an effective FM limiter circuit. While these radios might seem very sensitive in a controlled environment, they really suck in the real world. Commercial grade radios and public safety grade radios are tested to EIA 603D. If a radio is decent, it will have published EIA 603D performance specifications. Only a minority of the radios available for GMRS have such published specs. Sent from my SM-T350 using Tapatalk

In my state, the criminal enhancement is written "use of a communications device", so it really does not matter if a CB, Ham, GMRS, cellphone, or paper cups are used in the commission of a crime. Also the state laws prohibit interference with police as well as commercial broadcast. So in effect, if you are running a pirate radio station they can bust you. Sent from my SM-T350 using Tapatalk

You won't find Motorola Solutions (MSI) making or selling GMRS radios. They have licensed the production of cheap retail FRS and GMRS radios to an offshore manufacturer such as Giant. Those are crappy radios . You will need to buy a surplus public safety or business grade radio. I use Motorola Systems Sabers which happen to have the Part 95 certification. I easily tested 2 miles simplex, on foot with another radio inside my house. There are various Kenwood radios with Part 95 certification. Public safety Radios with Part 90 certification are generally equivalent in specs required by Part 95. Surplus radios are cheap and plentiful. But you will need software and a cable to program the channels. Sent from my SM-T350 using Tapatalk

These cheap radios have receivers that lack effective filtering of off channel and out of band signals. So if you are in an urban area, with powerful broadcast and communications transmitters, the receiver may get desensitized or outright interfered with by strong signals and distortion. Imagine going to a loud concert where you cannot hear the person next to you. Or being out in bright sunlight where you can't see ahead. In this case put on some blue blockers or sunglasses and now you can see through the filtering. Toss those cheap radios and look for some good used commercial radios like Kenwood or Motorola. Sent from my SM-T350 using Tapatalk

That's good to know! Sent from my SM-T350 using Tapatalk

I have not heard this. I woukd think there would be a ton of disgruntled APX users on these boards trying to get GMRS to work. They are a popular personal radio. The wide band entitlement key is required , but is free. Sent from my SM-T350 using Tapatalk

Nope, Frank himself! Sent from my SM-T350 using Tapatalk

Better than 90% of the Chinese junk flooding GMRS, much of it not certified for anything. You will need the wideband entitlement ID along with the software. As long as you stay away from digital modes on GMRS you will be unnoticed. Sent from my SM-T350 using Tapatalk

I have used it to optomize repeater tower placement for a project that required local in building coverage and there were tall pine trees throughout. It helped me in placing the tower where it could best serve. Sent from my SM-T350 using Tapatalk

By the way, if you are planning on a super GMRS repeater, consider installing a JPS SNV-12 voter and two or three diversity antennas and receivers on site. You can pick up 5 to 7 dB effective gain on the receive side this way. Bear in mind, it is only practical for a single CTCSS tone unless you break out the tone path and use some transmission gates and logic to steer the tones to a community repeater panel. Your mileage may vary... Sent from my SM-T350 using Tapatalk

You need to factor in the expected tower loading into the design. You could end up with 500 feet but unusable vertical real estate because a potential customer might want dishes and several collinear antennas. Also waveguide and transmission lines eat into the loading. 500 feet might be attractive for a broadcast antenna but unnecessary for LMR. You will find that larger transmission lines will be needed to have same ERP at 500 vs 300 feet. Antenna preamplifier will certainly be needed at 500 feet. Do a market survey to see who might be a potential client and the height they desire. Otherwise you have a half million dollar hobby, Sent from my SM-T350 using Tapatalk

You can buy "tell tale" temperature stickers that you install inside electronic equipment to determine the temperature extremes. While they don't tell you how long or whether internally or externally generated, they might be useful to determine if a failure was temperature related. Commercial repeaters are rated at 100% transmit duty cycle. In Public Safety use that is a norm.. for trunking systems, it is also a norm. Ham radio repeaters are frequently subjected to 100% duty cycle for a half hour or more. I would repeat the test over 100% key down and monitor the temperature rise vs time. Also monitor transmit power and current draw. Sent from my SM-T350 using Tapatalk

Hey kids, get off my channel! Sent from my SM-T350 using Tapatalk

It would be best to contact the entry point. If you were for example entering Canada at one location, then exiting in Alaska, you might have a valid argument that you are simply transporting it. Honestly, If you had it disconnected and stowed away I see no reason they shoud be concerned. That said a lot of US citizens are not trustworthy in the eyes of the Canadian authorities. Sent from my SM-T350 using Tapatalk

Are you entering and departing from same point? Sent from my SM-T350 using Tapatalk

The FCC has clearly not thought this out and is relying on the assertions of the manufacturers. I don't believe there is a BCL lockout requirement. Only a duty cycle that is insufficient given the multitude of radios that might appear on channel in an urban area or national park. Sent from my SM-T350 using Tapatalk

Geez does it ever end? The waiver granted to Motorola is not as benign as one thinks. When you add up a few dozen radios automatically reporting GPS location on one channel, the noise and interference will be horrible. Sent from my SM-T350 using Tapatalk

I used to chase down such interference for Motorola and it happened many times. Bad power amps, bad isolator panels. Once a 220 MHz ham repeater plus FM broadcaster mix. Sometimes lightning damages stations and they go bananas. . Sent from my SM-T350 using Tapatalk

Yeah if the repeater starts interfering with Public Safety after hours or on a weekend you definately need to be able to shut it down. If the FCC calls you and it is stuck on, do you have access to the repeater? Sent from my SM-T350 using Tapatalk

Same as when I won the lotto.. Sent from my SM-T350 using Tapatalk

Your freinds can use FRS equipment and you can communicate with them on a shared FRS/GMRS channel. But no, they cannot use your license. Even temporarily. They need their own license as GMRS licenses the individual and immediate family, not the station itself. Sent from my SM-T350 using Tapatalk

This is what is so very confusing about the MXT400. It is not FCC certified for wideband operation. If this software indicates anything whether narrow or wideband, 12.5 versus 25 KHz channel steps etc, . It really needs to be confirmed with a deviation meter and other measurements to confirm the radio is wideband. You could simply be toggling bits in the radio firmware that do nothing. I don't believe these MXT400 radios are capable of wide band at all. If they are, Midland could potentially get hate mail from the FCC for releasing the software to modify a certified radio . Sent from my SM-T350 using Tapatalk