In-building amplifier for 800MHz radios

[BigSteve80]

Hello;

I'm the chemical engineer for a very small chemical plant (I know very little about these radios, but we have no IT person, so I have to fix the problem). We were recently kicked off the tower for the plant next door and switched to a commercial tower several miles away. Since then we have lost pretty much all communications in our buildings, especially the steel-construction ones. Is there a commercially-available amplifier that I can connect to an omni-directional antenna outside and a uni-directional antenna inside? I got a quote to do the work from the company we are leasing the tower usage from, and it came to $2500 per building, which seemed kind of steep.

 

[SkipSanders]

If you don't know what you're doing... DON'T.

You can easily cause a feedback radiating jamming signals for long distances with 'amplifiers connected to antennas'.

First thing, did you modify your license to show the new antenna location? The FCC doesn't allow you to just move antennas without getting permission.

There are commercial systems to handle getting coverage inside buildings, using 'leaky' coax connected to an antenna outside the building, and other methods, but they're not for the amateur to design.

 

[N4DES]

Only the licensee is authorized to install such a device per the FCC Rules. You as an end user would be violating this rule.

$2500 per building is not expensive as I have seen such installations go as high as $10,000.00.

 

[ILMRadioMan]

If you are talking good quality BDA's, then that price isnt wholly extreme. That being said, the others are right, perhaps it would save you time and money in the long run to get a professional out there.

 

[w8jjr]

Very cheap. I would be aware with a price like that. Last set up I worked on was 12,000.00 a building. Just be sure your getting a quality system and service.

 

[comsec1]

radio tech

unless your repeater has a RJ-45 antenna jack you need a radio tech not an IT person, the two are not interchangable.

 

[NeFire242]

How about switching to talk-around? lol

 

[byndhlptom]

building system

What about trying a simple passive repeater system. An outside yagi pointed at the tower, a short coax run to an inside mounted omni antenna. You probably could kludge up a test on the cheap. This has been done in high rises / tunnels etc. The Lossy coax referenced earlier is also an inside option.

good luck

tom

 

[ILMRadioMan]

I've seen the yagi to omni work inside a fire station.

 

[N4DES]

Depending on the proximity to the transmitter/receiver site passive systems are a hit and miss. I have never seen one to work properly except in a point to point hill top microwave system where every component is stationary and the fade margins are calculated.

 

[BigSteve80]

unless your repeater has a RJ-45 antenna jack you need a radio tech not an IT person, the two are not interchangable.

That's what some people say about mechanical engineering, and civil engineering, and safety, and electrical, and instrumentation being done by someone with a chemical engineering degree, yet here I am doing it... LOL