Noob who needs a recommendation (or 40)

[dhuntsacbee]

Hello, all. This is a doozy, and I apologize in advance that I know a little but not a lot -- I've learned in other endeavors that knowing just a bit can be plenty dangerous, and I just want to do the right thing... solid state within reason. The ultimate goal is to be able to distribute decent quality radio traffic to multiple points (maybe 10 tops) in a room that's 60 x 60.

I have a setup where I've got two 996P2s, two 15Xs and three 325P2 handhelds, and I'm in a place where signal strength is a major issue. I have LMR400, ample Cat6 and can get ample audio cable, and I know how to cut and crimp my own stuff. I have a neat collection of BNCs, LMAs, N-types ready to be used on fresh cabling. I've got fast internet, even some wifi. I have 10 repurposed PCs and a handful of SDRs that eventually I'd like to set up and stream privately or put on Broadcastify.

Full disclosure: This is for my employeer, and I'm lucky 'cause I could never, ever afford this gear for my own stuff at home (a Radio Shack-labeled Whistler and a 12-year-old Mac).

The building I'm in is postwar 1950s concrete, steel and brick. It's a bunker on the second floor of a three-story structure with only one window looking to the outside world. That window is 35 feet due east of my desk. Then, I've got the ability to do a cable run to the roof, but that's at least 100 feet of LMR400, of which I have 400 feet.

The problem is that the scanners need to be scattered throughout the room, which is an open-floorplan office with an elevated steel floor for cabling, a la '80s style. Building services has said for a year, "yeah, we'll run your cable through the run to the roof," though at one point they said they wouldn't then they couldn't and then said I needed 400 feet of cable (which I know means the signal is worthless).

OK, to the point: Multiple people need access to the scanners, and it's not feasible to have any more scanners than I've already got. I have a multicoup I bought from ScannerMaster, and before I put sweat and tears into running cable through the room, I want to make sure I've got this thought out well enough to outlast me, and likely this institution.

Ideally, I'd use one of my 800MHz+ Log Spiral Antenna with Suction Mounts from Hex and Flex on the window, some 35 to 50 feet away from where the radios are. Put a preamp on this at the source and then run LMR400 to the multicoupler and then distribute out eight ways.

But then I had another think: The people who use these scanners don't know how to use them -- they are just seeking the audio. Would there be a way I could set up all the scanners in one place (near the window and antenna) and then distribute the AUDIO out to various places around the room using an existing audio amplifier and speaker equipment. Side tangent: In a perfect world, I'd take two weeks off from work and figure out how to fabricate some 3D-plastic built devices that would house a speaker, a scan button and a hold button with a minidisplay using custom-built software that ports the display info similar to what you see in on-screen controllers from the likes of Freescan and ProSCAN. Maybe someday after my wife leaves me...

Now I didn't go out and buy the best and newest scanners that enable web control, mostly because of the limitations the company I work for has put on equipment being on the network (read: super locked down and cyberconscious). I have an external cable modem service that I can hook into that bypasses the network, but again, I'm forced to run cables through the room and I can't make it look like my shack.

Again, I'm a total amateur at all this radio stuff -- I'm very eager to learn and don't have many places besides these forums to do it -- but I'm handy with electrical components and "maker" s---. I don't have a real budget to do this, so I have to get inventive. The ultimate goal is to be able to distribute decent quality radio traffic to multiple points (maybe 10 tops) in a room that's 60 x 60. I want to get the best possible signal with the equipment I have and share it with people. I can't move desks or huddle the team in far corner of the room to make this simple, and I can't tear the place up to run cable 50 different directions (knowing that splitting and distance are weakening my strength).

What do the veteran minds think I should do? Is there a third (or fourth) approach I'm not thinking of?

Thanks, in advance, for not taking me out to the woodshed.

 

[mmckenna]

Skip the stick on window antenna.
Put a decent antenna on the roof. Which antenna you need depends on the frequencies you are trying to listen to. A discone antenna -might- be a good choice, but if you are only listening to a specific band or two, you can get better performance from band specific antennas.
Figure out what the -real- cable length is going to be. If you are on the second floor of a 3 story building, and they want 100+ feet of cable to reach, there's an issue.
LMR-400 -might- be fine depending on the actual cable length, frequencies you want to listen to, and how much signal strength there is on the roof. If any of those are a challenge, then put the money into better cable.
You -will- need to have lightning protection on that cable run. That's required by the National Electric Code and is NOT optional. Near the point where the coaxial cable enters the building, the protector would be installed and connected to the building ground system, building steel or other suitable ground. This isn't impossible to do, and a facilities guy with a bit of electrical experience should be able to handle it. If not, get an electrician to do it correctly. Better yet, get a reputable radio shop to do the antenna/cable/protector/grounding installation for you.

As for distribution, it really depends on what you want to do.
If you want to put a scanner at each desk, then run the coax coming from the roof to a central point and install the multicoupler there. Distribute out from the mulitcoupler using RG-6 cable to each desk. You will likely need an amplifier to boost the signal to overcome splitter losses.

If you want to have all the scanners at a central location and just distribute audio, then you'll still need the setup above, as well as audio amplifiers to handle the distribution. Usually the audio output from a scanner will drive a speaker, but if you are going to feed the same audio to separate speakers, you're going to need to add some amplification.
If you want to really get fancy, you could distribute multiple audio feeds to each speaker and have a selector switch, but that will take some work.

Probably putting each scanner at a desk will be your easiest approach.

I'm sure there are other approaches to do this, and you'll probably get some good ideas. Distribution of audio via IP would work, but then you'll have to convert scanner audio to IP. Possible, but is going to take more work and equipment.

 

[mmckenna]

I'll add this.
I've got a similar setup in a 911 center. We have a dedicated VHF antenna on the roof that enters the building, goes through a lightning protector and then to a distribution splitter. That feeds 4 Motorola CDM-1250's. Since all the local agencies we want to listen to are on VHF analog, that works well.
From the CDM-1250's, we take an audio feed from each one and send it to the radio console system. Each dispatcher has a button for each of the 4 radios and can set the audio independently.

 

[dhuntsacbee]

I'll add this.
I've got a similar setup in a 911 center. We have a dedicated VHF antenna on the roof that enters the building, goes through a lightning protector and then to a distribution splitter. That feeds 4 Motorola CDM-1250's. Since all the local agencies we want to listen to are on VHF analog, that works well.
From the CDM-1250's, we take an audio feed from each one and send it to the radio console system. Each dispatcher has a button for each of the 4 radios and can set the audio independently.

This would be the ideal setup in my opinion as I’ve had the 15Xs and handhelds at their desks for six months, and they’ve been reluctant to learn them, let alone use them. Part of that is a generational thing, but let’s not go off on a tangent with that.

 

[dhuntsacbee]

This is very informative and helpful, thank you! I definitely understand what you mean about grounding, and perhaps that’s why the building folks were reluctant. I may be able to find some money to hire a contractor for that specific purpose, and perhaps that’s where I should start. After I get assertive about the measurements.

Seriously, this is a wonderful starting point. Time for me to do some homework!

 

[mmckenna]

If your budget allows, hire a radio shop to do the install. While installing coaxial cable isn't a big deal, you don't want your average electrician trying to yank it in like they'd pull normal electrical wiring. They'll also understand about keeping the run as short as possible. My concern is your building maintenance guys will just route the cable whatever way is easiest. That could add a lot of length to the run, which will reduce your signal.
A good radio shop will have the right tools and test gear to do it properly.
But, be aware, running cable through a building has some challenges. There are rules regarding the type of cable that's used specific to fire propagation, smoke, etc. If you have regular off the shelf LMR-400, it may not have the ratings to be routed out in the open through a building. You may need "riser" or "plenum" rated cabling depending on the route.

 

[jonwienke]

If cable run length is an issue, upgrade the scanners you have to SDS200s, put them in an upstairs room near the antenna, then use the LAN ports to stream the audio and such to the rest of the building.

 

[slicerwizard]

Preamp at the antenna should handle the cable run and the splitters.

 

[krokus]

Using a PC, or two, to stream the various audio outputs to the internal network would be useful. Then the users can select which audio feed(s) they want, with audio players.

The scanners can be kept in a central location, keeping the RF cabling to a minimum.

 

[dhuntsacbee]

Thanks to everyone who threw down knowledge. It's very much appreciated, and I'll keep you all posted on the results.