Premade RF Modules and FCC Licensing Requirements
http://www.quasaruk.co.uk/acatalog/DSQ-ALPHA-TRX-3.pdf
International Radio Approvals_2008.VIII
K.
The above linked datasheet doesn't specify any properties related to SRD (small radio device) regulations except output power.
Exact frequency settings are already unclear. I expect, that a more detailed manual is available. It's an interesting question,
if the manufacturer specifies e.g. harmonics and spurious emmisions according to ETSI or FCC standards in any document. If so,
you can basically refer to it and in my opinion are allowed to use the part in license free applications without performing
measurements on your own. This applies at least for EU and U.S. The application specific frequency and duty cycles restrictions
have to be kept, of course, also no antennas with higher gain than a dipole are allowed.
Here is an example of a transceiver module with a declaration of conformity to ETSI specifications:
http://www.lprs.co.uk/redirect.php?a...ER400TS-02.pdf
Each and every country has its specific requirement for wireless transmission. They primarily revolve around limiting the maximum effective transmit power, operation within certain pre-approved frequency bands, and insuring you do not interfere with other wireless users (even at other frequencies).
The FCC is the govt. group in the USA that controls those rules. There are roughly three groups of users that the FCC governs:
Licensed intentional users (like in a licensed radio for cab drivers)
Un-licensed intentional users (like in your laptops WLAN card)
Un-licensed un-intentional users (like in the stray noise your computer monitor spews out)
So, if you are a licensed user...you need an actual license from the FCC. You can buy your equipment from a vendor who has gone thru the various tests to get an FCC type approval, but you still need to get a license for each piece of gear you want to use. (if you run a cab company, you need to have a license for you and your cabs to have this equipment in it, for example). There are variations too, like if you are doing wireless telecom backup you can buy type approved gear, but only have to use a frequency coordination service to get approval to use it.
If you are an unlicensed user, you obviously do not need a license. But you DO NEED to somehow prove to the FCC that the equipment you are using has been previously tested and approved to be used in an unlicensed fashion. The requirements covering unlicensed equipment are mostly covered in the CFR 47 Part 15. You can view those rules, for free, at the FCC.gov site.
So, assuming you are talking about using unlicensed Part 15 gear in a design of yours. You either have to
1) use PREAPPROVED part 15 gear WITHOUT changing its design in anyway. You will know the gear is preapproved because it will be sporting an "FCC ID" number printed on it. No visible FCC ID number...it is almost certainly not approved gear! You can not take the unit with the FCC ID number, and modify it as in adding a 40 db gain antenna to it, or change bias resistors on the board to provide more transmit power, for example. That is why the FCC requires board pictures...to tell if you are using one that has had any modificiations from the one that was previously approved.
or
2) design your own gear, freeze the design, get it tested at a certified test shop, and submit the test report (along with schematics, pictures of the board, users manual, etc) to the FCC. The FCC will read the report, and if they like it, they will send your own coveted "FCC ID" number. I do a fairly brisk business providing part 15 Pre-Compliance testing for people who want to tweak up their designs for optimal performance, but to be just under the FCC limits, prior to doing the final test chamber testing.
Interestingly enough, if you have a unit with an "FCC ID" number printed on it, you can usually search and find the submitted information on that unit.
Rich
Added after 21 minutes:
The ALPHA-TRX915S seems to have the electrical performance parameters that would allow it to technically operate under the Part 15 rules. However, note that it is not shipped with an antenna...so they are not going to be able to get an fcc ID number without hooking a specific antenna to it, and submitting the test. This module seems geared to someone buying it, putting it into their final unit with their own integrated antenna, and then going thru the Part 15 testing.
It is possible that this house has done their testing, and has an FCC ID number for the module (when combined with a specific antenna part number). It is not mentioned in the spec sheet though, so I highly suspect they have not done that. You should ask them! Be careful...often these type of modules meet SOME of the requirements, but fail the 2nd or 3rd harmonic power levels, etc. In other words, you can use them only after you add additional circuitry, such as a lowpass filter, emi shielding, specific types of antenna with poor harmonic performance, etc.
So....I think this has helped quite a bit. I've also looked around and talked to a few other people. I've found one device under S10 USD that comes with an FCC ID and a fixed antenna. Not a bad little device and I'll probably get a couple and play with them but I'm still a little curious about the finer details I've come across. Here are the details in anyone's interested... Module:http://ww1.microchip.com/downloads/e...Doc/70329b.pdf and Chip:http://ww1.microchip.com/downloads/e.../DS-39776b.pdf
1) Looking at http://www.fcc.gov/ftp/Bureaus/Mass_...pn19910724.pdf, it looks like I wouldn't have to worry if my devices don't transmit at more then 200 ft or am I reading this incorrectly?
2) Looking at http://www.fcc.gov/Bureaus/Engineeri...3/oet63rev.pdf under the section "Home-Built Transmitters that are Not for Sale" on page 3, it looks likes there might be a little bit of leniency there. I'm assuming that "Part 15 transmitters" are ones that fall in the 'under 200 ft or range' category. 3) And lastly, I've talked with a Ham radio operator and he was saying I'd be fine if I were to get an amateur radio license since all of these simple little devices seem to operate at amateur frequencies. This would maybe be the way to go since it's only S15 and I wouldn't have to worry about range or FCC IDs (as far as I know).
Just looking for a sanity check if anyone wants to comment on my finding or thoughts. Thanks.[/url]
in point 1), you are missing the meaning of the word "broadcast". That little memo describes how you would be able to "broadcast" (music or voice) over either the AM radio band or FM radio band. In other words, you are limited to 0.53 to 1.7 MHz using amplitude modulation, or 88.1 to 107.1 MHz with Frequency Modulation.
hi there
and in your point 3, you also need to know .....
yes you could have an amateur licence and be able to use those devices but 2 things come to mind ....
1) the style (type) of transmissions would have to be of an amateur radio, not commercial nature
2) if the devices ... namely any transmitting device was to be remotely located
from your ham shack it would need its own separate licence like any other
repeater or beacon etc and would need to have full remote access control
so it can be shut down promptly in times of some sort of failure ....
eg. transmitter becoming locked on
I am also of the understanding that this is the case if the transmitter is at your place of residence but you are not in "hands on" control of the unit.
eg .... the unit is in and in use during the day whilst you are away from you home at work ... ie it is unattended and therefore it would need its own licence issued.
I had looked into this quite deeply in days gone bye when I wanted to site a repeater system at my own home location. I was told that if I was not in attendance it could not be in use unless it had its own call allocation and remote
control (normally done by DTMF tones)
cheers
Dave
VK2TDN