Would it matter what transmitter I used, so long as the field strength limits set by Part 15 weren't exceeded? For example, could I run a commercial LPFM transmitter at .1 watts (or whatever), and still be legal if I didn't exceed the limits?
Thanks,
Chris
you need to use a type certified transmitter under part 15. however running on FM if you have access to a FM FIM and set your Tx up for 250uV/m @ 3 meters and verify it then you should not have a problem what ever you use. keep in mind that you need to also keep within a 200khz bandwidth.
on AM the FCC appears to be getting some teeth, so it's adviseable to go with a type accepted Tx there as well. Either under Part 15.219 or 209.
Thank You,
Rev. Robert P. Chrysafis
Universal Life Ministries
http://www.ulc.org
Moderator Hunterdonfree
http://groups.yahoo.com/group/hunterdonfree
you need to use a type certified transmitter under part 15
Only partly true. If you choose to use a transmitter that is not type accepted the responsibility for Part 15 compliance falls on the user. So scratch built, kits and mods are OK as long as you are willing to accept responsibility for assuring your final set up meets the requirements of Part 15.
On FM it is very difficult to be compliant and regulatory scrutiny has never been tighter.
on AM the FCC appears to be getting some teeth
THe FCC always responds to complaints from licensees. If your broadcast upsets a licensed station your operation will be looked at. If you exceed feld strength or use a mis-configured set-up you will be asked to stop broadcasting and to change your set-up before you broadcast again.
If you don't cooperate you will get an NOUO
If you still don't cooperate you will get an NAL
So, legal broadcasting without a license is challenging and the ultimate range is severly limited - but it's still FUN 🙂
Experimental broadcasting for a better tomorrow!
Hi Chris,
From your user name I conclude you are an amateur radio operator. You therefore are capable of reading and understanding the FCC part 15 rules regarding FM. What is not obvious from the rules is that the power delivered to the antenna to produce a legal field is approx. 11 nanowatts. This is one nine millionth of the .1 watt that you cited.
The field strength limit (there is no power limit) is very restrictive in terms of range. If you decide to use the tx. you described, you will have to demonstrate, if asked by the FCC, that your station meets the requirements. With the power levels you mentioned, this would require effective shielding of leakage from the transmitter and a very high attenuation of the ouput signal before the antenna as well as documented use of a valid field strength measuring device.
As was mentioned, the responsibility for compliance with the FCC rules rests with the operator and not the manufacturer, as it is on the ham bands. Gather all the information you can and make an informed decision.
Be very careful with this.
Neil
Neil makes a great point about leakage, and not the type you get from too much Olestra 🙂
Years ago I ended up with an NOUO, in part because the dummy load at the end on my leaky cable radiator had a bad leak itself, one that I wasn't aware of.
Ouch!
Experimental broadcasting for a better tomorrow!