Radio implementation for a new company

[KelzClive]

Many times it has been said that "you get what you pay for". This couldn't more true when it comes to 2 way radio communications. The reliability comes with a price and what you get, will sure be worth it in the end.

 

[MUTNAV]

I didn't save them.

I ran about 5 of them through.
One was off frequency by about 500 Hz, another was off 550Hz.
Two of them were over deviating (DTMF). One by quite a bit.
The others were under deviating DTMF. Yeah, DTMF aint a big deal, but not sure if it was just DTMF or the entire radio. Since there isn't a way to align them, I didn't follow it any further.

And there was one that flashlight didn't work!!!

Either way, the were the wrong radio for the job.

I've never thought of that, use DTMF as a two tone test generator !!! Great Idea !

Thanks
Joel

 

[MUTNAV]

Has the O.P. , and business, considered, since this isn't a life safety thing, the use of company issued cell phones?

Thanks
Joel

 

[pandel]

I had the same thing happen when I went to work for an employer years ago. They were using Wally World kids radios in a professional medical office and thought nothing of all the beeps, boops and tunes being played by the employees all day long. Jump forward a couple of years and I'm promoted to manager. My first move was to buy professional radios and teach a class on RADIO ETIQUETTE. (No, the entire office + patients don't need to know when you need a bathroom break or what you want for lunch!) They fought me tooth and nail about spending the money but when I retired 25 years later, their system was still running!

 

[celestis]

From my experience, in your situation....you got very bad advice trying to use UHF. VHF should work MUCH better and without an expensive repeater.

I see this nonsense a lot
A Motorola dealer in Indianapolis managed to scam my city's PD into scrapping an analog VHF system for an unneeded 800 MHz P25 system
The fire department fortunately didn't have their head in their rear and kept their analog VHF system

 

[speedway_navigator]

I remember when Speedway PD and FD went from VHF to conventional 800 MHz repeaters. They had those until they joined MECA. It was a GE system, don't know how Motorola missed out unless it was low bid. It was an improvement, the PD's system was csq and they got co-channel traffic from Ohio in the winter. Their portables had trouble getting to the station from inside the track, during May I put a base in the pagoda for them

 

[ElroyJetson]

Adding my voice to the choir. Your communications system can be, and in emergency scenarios WILL BE, a critical life-and-safety system. It's not any less important than having electrical work done to code, fire extinguishers, a fire alarm system, and a fire suppression system if warranted. Communications is not any place to cheap out. Even a basic system needs to be engineered by someone qualified to do it, with equipment suitable to the needs of the organization. It's no place for the cheapest radios money can buy and should not be installed by a radio company that has a booth at the local flea market on weekends.

When I was working, we were a small company but we developed and installed systems to a rigid practical performance standard: 100 percent reliable coverage within the coverage area defined by where the customer operates. All radios used had to be approved, FCC certified models, currently supported by the manufacturer, and bench tested and aligned to factory specs or better. Operating frequencies licensed, coordinated, and verified interference free.

It was sometimes difficult to achieve the 100 percent coverage on campus standard, because we know that in building coverage is a very different challenge than outdoors coverage. But we got the best coverage the customer was willing to pay for.

Where there are any safety concerns, let the radio system be professionally engineered, designed, and installed. It's the only sensible way to go.

 

[rrmenasco22]

Just a thought, Does peanut handling or storing create any amount of fine particles that could float in the air? W with a spark or flame could it go boom? You might be looking at buying mine (like coal mines) safety radios. Explosionproof housing. You could run slotted hard transmission lines along the entire tunnel for an antenna(s). The idea of a splitter for an antenna is novel at best. Use two receivers on the two or three antennas you want then combine them at the audio level, not at the rf level. However, you could probably split the base station transmitter power (after the duplexer) through a splitter to three separate antennas.

In a plain vanilla system, as you describe, the weakest link is the HT signal getting to a main receiver. Your problem also has a weak signal from the central transmitting antenna to the HT receivers. I'd take your money. Use one transmitter split to three (or more) antennas. Three or more receivers with separate antennas and audio from the three remote receivers placed close to their antennas. Run audio cables back to the main control point or dispatcher. Mix the three or more audio feeds into a cheap church sound mixer and speaker. You need separation of the receiving antennas and transmitting antennas. Remember you have asymmetrical TX/RX curves. They can be a hundred feet apart and at different hight and still work effectively

All that being said, a high-noise floor at any receiving location could make things impossible. Try running the design I talked about through a simulator and you would be spending three times your budget, This shade tree engineering at its best?

If you're still reading these posts you may be looking for a silver bullet to fix your problems, No judgment, I am still looking too.

 

[mmckenna]

Just a thought, Does peanut handling or storing create any amount of fine particles that could float in the air? W with a spark or flame could it go boom? You might be looking at buying mine (like coal mines) safety radios. Explosionproof housing. You could run slotted hard transmission lines along the entire tunnel for an antenna(s). The idea of a splitter for an antenna is novel at best. Use two receivers on the two or three antennas you want then combine them at the audio level, not at the rf level. However, you could probably split the base station transmitter power (after the duplexer) through a splitter to three separate antennas.

I had the same concerns and mentioned that in one of the earlier posts. Combustable dust from processes is a concern and this is where government regulations save lives. Cheap Chinese Radios are NOT the solution.

In a plain vanilla system, as you describe, the weakest link is the HT signal getting to a main receiver. Your problem also has a weak signal from the central transmitting antenna to the HT receivers. I'd take your money. Use one transmitter split to three (or more) antennas. Three or more receivers with separate antennas and audio from the three remote receivers placed close to their antennas. Run audio cables back to the main control point or dispatcher. Mix the three or more audio feeds into a cheap church sound mixer and speaker. You need separation of the receiving antennas and transmitting antennas. Remember you have asymmetrical TX/RX curves. They can be a hundred feet apart and at different hight and still work effectively

Mixing crappy signals in with good signal results in crappy audio.

The solution is to use multiple receivers fed into a comparator (voter) that would select the signal with the highest signal to noise ratio and feed that into the transmitter. I've got a few systems that run this way and it works well. JPS SNV-12 for the win.



The OP hasn't been back since January 25th. I think he's probably moved on and let a professional do this, as was suggested many times.

I haven't heard of any peanut processing plants blowing up recently, so maybe they've got it sorted out.