FCC permission for roof XMIT antenna?

[Prospect62]

Hello all,

I work for an "entity" that is looking into adding the capability of transmitting to the local fire/EMS agencies in the event of an emergency at out large site. I am helping with sourcing the proper radio, power supply and getting written permissions from the fire/EMS agency heads to transmit on the frequencies.

We work out of a two-story building. I have received approval from our managers to erect a rooftop antenna capable of transmitting and receiving in the band in question, and have picked out equipment. Our on site technicians are more than capable and will handle proper installation.

My question is, what additional FCC permissions will we need to transmit from this rooftop antenna on these frequencies, with approval from each respective license holder? The antenna will not be on a tower and will not be a structure unto itself, just an antenna affixed to a small mast on the roof our 2-story building. Power output will be in the neighborhood of 40 watts, on VHF high-band.

Do we need to apply for permission with the FCC or is it incumbent upon the license holder to amend their license to include our transmitter?

Thanks for any real info. I plan to contact the FCC but I figured there might be someone here with real-world experience who may be able to point me in the right direction.

 

[mmckenna]

It would depend entirely on what the fire/EMS agency is licensed for.
Getting permission to operate on their radio system means you are operating under their license. Their license would show the area of operations (often shows as ## KM radius around the repeater) for MO stations (Mobile/Portable radios). What you are doing would be considered an FX station, fixed, as in attached to a fixed location.

There are three options I can see:

1. Ignore everything and just do what you want. (Not recommending it, just saying it because someone else will post it as an option if I don't)
2. The license holder for the system you'll be connecting to can add you as a fixed station, which will require updating their license, and may require limited power/antenna gain.
3. Try to get your own license and license as a fixed station. You'll need to get sign off from the existing license holder and you'll need to involve someone to assist with the licensing.

Doing it right and getting properly licensed would be the best way to cover your rears.
As for the license, when you apply, you'll need to provide information about how the antenna is mounted, I believe "BAT" is the code for building mounted antenna. You'll need to know height above average terrain, antenna gain, feed line losses and radio output power.

 

[mmckenna]

90.421 might have your answer:

§90.421 Operation of mobile station units not under the control of the licensee.
Mobile stations, as defined in §90.7, include vehicular-mounted and hand-held units. Such units may be operated by persons other than the licensee, as provided for below, when necessary for the licensee to meet its requirements in connection with the activities for which it is licensed. If the number of such units, together with units operated by the licensee, exceeds the number of mobile units authorized to the licensee, license modification is required. The licensee is responsible for taking necessary precautions to prevent unauthorized operation of such units not under its control.

….stuff removed for clarity….

(c) In addition to the requirements in paragraphs (a) and (b) of this section, frequencies assigned to licensees in the Private Land Mobile Radio Services may be installed in the facilities of those who assist the licensee in emergencies and with whom the licensee must communicate in situations involving imminent safety to life or property.

In other words, it would be a good idea to talk to a frequency coordinator about this. You can certainly try the FCC, but the people at the 800 number usually are not as helpful as we'd like.

 

[n5ims]

Also remember that you may have zero say in what equipment you'll be able to use. The agency or agencies may insist that you use only the equipment that they indicate and perhaps even require that the agency own and lease it to you for your use (so they will have full control and even be able to remove totally at their whim). They will most certainly give you some very restricted rules for when and how to use the radio.

 

[Prospect62]

90.421 might have your answer:

§90.421 Operation of mobile station units not under the control of the licensee.
Mobile stations, as defined in §90.7, include vehicular-mounted and hand-held units. Such units may be operated by persons other than the licensee, as provided for below, when necessary for the licensee to meet its requirements in connection with the activities for which it is licensed. If the number of such units, together with units operated by the licensee, exceeds the number of mobile units authorized to the licensee, license modification is required. The licensee is responsible for taking necessary precautions to prevent unauthorized operation of such units not under its control.

….stuff removed for clarity….

(c) In addition to the requirements in paragraphs (a) and (b) of this section, frequencies assigned to licensees in the Private Land Mobile Radio Services may be installed in the facilities of those who assist the licensee in emergencies and with whom the licensee must communicate in situations involving imminent safety to life or property.

In other words, it would be a good idea to talk to a frequency coordinator about this. You can certainly try the FCC, but the people at the 800 number usually are not as helpful as we'd like.

That is very helpful, thank you. What exactly is a "frequency coordinator"?

The agencies we are looking to inter-operate with are very friendly and would likely have no restrictions on what equipment we use, nor would they be too particular on guidelines for radio use as our staff is probably very much more professional than most of theirs. Obtaining their permission to operate on their frequency in the event of an emergency will be easy I'm sure, I was just wondering what we would need to do to be legal with the FCC as it pertains to being another transmitting station on the frequency.

90.421 is encouraging, but it pertains to mobile and portable units, not a fixed base station.

 

[mmckenna]

That is very helpful, thank you. What exactly is a "frequency coordinator"?

The agencies we are looking to inter-operate with are very friendly and would likely have no restrictions on what equipment we use, nor would they be too particular on guidelines for radio use as our staff is probably very much more professional than most of theirs. Obtaining their permission to operate on their frequency in the event of an emergency will be easy I'm sure, I was just wondering what we would need to do to be legal with the FCC as it pertains to being another transmitting station on the frequency.

A frequency coordinator is a person or company that is authorized by the FCC to work with agencies to identify frequencies that can be licensed. The FCC will need approval from a frequency coordinator before they assign a license, in most cases.

Frequency coordinators are basically the spectrum managers.

You could start by contacting these guys:
https://www.apcointl.org/spectrum-management/frequency-coordination/

-They are not the only frequency coordinators, there are others-

Anyway, talk to them about what you want to do. You'll want to have the call sign for the agency you want to work with so they can look at it. They'll tell you how to best proceed.

90.421 is encouraging, but it pertains to mobile and portable units, not a fixed base station.

"..may be installed in the facilities of those who assist the licensee in emergencies and with whom the licensee must communicate in situations involving imminent safety to life or property."

Key word is "facilities". But I don't feel comfortable interpreting that into saying it's OK. And anyway, "imminent safety to life or property" usually translates into "not a planned thing", so that sort of rules it out.