Need some help in identifying a base station.

[SteveC0625]

One of our hospitals has a Motorola base station used for ambulance to hospital communications, and we are having a bit of a problem identifying if this radio is NB capable.

Best I can tell, it is a Compa Station, but no better model name on it anywhere. The model number is G63RLB7106B. There is a file over on batlabs that gives some partial decoding info, but not enough to determine NB or even power or product line.

We do know it is VHF (155 Mhz.) and at least two channels. And it is controlled by a T1613C Tone Remote in the Emergency Department. Physical dimensions of the box are 24" wide by 30" tall by 8 to 10" deep. The visible front panel is black with louvers.

I am still trying to determine when the radio was purchased, and if possible, locate the actual purchase paperwork.

Any information is greatly appreciated.

 

[davidgcet]

no, it is far from being NB capable, it is about 30 years too old to even consider it. time to junk out another Compa.

 

[gary123]

it is NB capable if you dont mind doing some hardware changes.

The transmitter is simple simply set the deviation to 2.5 khz and adjust the PL/DPL injection accordingly.

The reciever will require changing the IF xtals from the normal 7.5( aprox) banmdwidth to more narrow 4(aprox) bandwidth. There are kits for some radios out there we did it with several MSR series.

This isnt as good as getting a newr narrowband unit but it is cheaper. Although Ebay sometimes can list a treasure.

 

[chrismol1]

Compa is a Motorola Micor base station radio so that gives you a little info about its age (old old old) and NB details

 

[davidgcet]

that is NOT NB compliant, unless the manufacturer certifies the modification then the unit cannot be modified and made legal. google it, this is explicitly stated in the FCC order and has none the less been clarified numerous times. Moto is not certifying any out of production units that were not already NB compliant at time of manufacture. because of this the MSF and MSR series stations are useless to any part 90 VHF/UHF license holder after 1/1/13.


it is also not as simple as setting the deviation to 2.5k, a dead key with no mod is still jsut as wide on the spectrum analyzer and therefore will get into any adjacent NB channel.

EDIT: http://www.repeater-builder.com/motorola/motorola-suffixes.html gives the breakdown, the RLB is a MSF not a compa. compa was way before it's time. i went by the OP saying compa, but after looking up the model (starts with a C not a G) i see it does not matter as the MSF is not NB compliant anyway.

 

[SteveC0625]

Curiouser and curiouser!

David, I used the same chart that you looked at, and the MSF has another three letter code also which leaves me unsure of which is right. But it may not matter... (read on)...

Also, at How to Translate Motorola Serial numbers to Determine the Date of Manufacture - this chart helps decipher the age (date of manufacture) of any Motorola unit based on the serial number. The SN on the radio in question is 684CUY0152 which decodes to the second half of December 1994. That pretty much tells me that the radio is clearly not NB capable and will join a lot of other gear on the junk heap.

But, looking at the FCC license, they are licensed for three VHF channels which are used in EMS here in our area. This radio is supposedly a single channel unit so it may not even be the EMS radio. They also had a license on 163.2500 for paging in the not so distant past so a single channel unit might be their old paging radio.

So I am guessing another site visit is next on my agenda to figure out what they really have. I suspect there is more to be found than this single radio.

Thanks to all for your willingness to help.

 

[ramal121]

it is also not as simple as setting the deviation to 2.5k, a dead key with no mod is still jsut as wide on the spectrum analyzer and therefore will get into any adjacent NB channel.

Umm, OK. So just how does a unmodulated CW carrier occupy the entire channel bandwidth? Must have missed class that day.

Back to the subject, whether it's a MSF or Micor compa or somewhere in between, those are unsupported models and I would think this would be a good time to upgrade to something current and keep the peace of mind.

 

[radioman2001]

That might be a MSR2000, which is not narrow band qualified, have to look at my UHF station. Where is the model number plate, on the side or on the front on the top rail that will tell you. MSF stations have all their connections made from the side plate about 6X6 inches.

It's amazing how much people misunderstand the Narrow Band rules. A digest of information from the FCC website and all the Q&A's that have taken place in the last year or 2. "Unless the radio was type accepted for 12.5kc when it was manufactured, then it is not narrow band qualified" All those narrow band kits are from what I have read are only for radios that fell between the cracks, radios that were certified with a 12.5kc type acceptance but left the factory wide band. There weren't that many some of the early 1225 radios from Motorola are some.

An alternative to a total replacement of a 110watt vhf station might be using a NB low power mobile (2 to 30 watt) and run it through the MSF or Micor PA. That's how I intend to solve my repeater problem, until I can find a reasonably priced high split UHF repeater. Even E-bay prices are insane for a used Quantar never mind a MTR.

BTW any station that is used for paging doesn't need to be narrow band compliant. Just make sure that if you are licensed on a frequency that is not list as a paging only in 90.20 or 90.35 that you apply for a waiver to keep that frequency wide band. A coordinator can help you with that.
If you need some info take a look at ULS Application - Public Safety Pool, Conventional - 0004542548 - NEW YORK HOSPITAL New York Hospital got the waiver for their station.

 

[davidgcet]

yeah i said that wrong, my fingers typed different than my brain was working(or my brain just was not working last ngiht either case is possible).

under Carson's rule the non-compressed voice frequencies would still reach up to 15k of occupied bandwidth, this is why NB compliant transmitters use different audio filters to cut frequencies generally above 2000 hz. 2(2.5*2)= 10khz. but a wideband transmitter has filters passing up to 3000hz, so 2(2.5*3)=15khz which is outside BW. this is why NB radios use more compression and expansion than their WB counterparts, to make the clipped audio sound normal at the RX.