FM Transmitter

[Emmien]

This is a slightly domestic question, but nobody else seems to know.

 

I am doing a lights to music Xmas light display this year and want to transmit the audio over FM. Can I just plug it in, tune it to any station and leave it, or will I get in trouble?

[themadhippy]

assuming your in the uk youll get in trouble,without a licence your running a pirate radio station

[david.elsbury]

Where in the world are you?

[paulears]

Why would you want to tune it to a station? It's unlikely your cheap get across the car device will travel very far? If on the other hand you have a more powerful one, expect people who do NOT want to hear it to complain when it wipes out their favourite radio station and call the authorities to complain. In the UK, illegal radio use is too much time and trouble to investigate, but a pirate radio station always gets action, and very high fines. If it's a low powered device, it won't have and distance, and worse still, how will people know to tune it in? You can't advertise 102.4MHz can you? Somebody will report you, forgone conclusion. I had one of these devices and it wasn't even strong enough to get to my house from the van parked outside!

[kurzweil_dude]

Need loads more information.

Country?

Size of application / site?

Type of application - static / moving?

etc

[musht]

If its over 50uW you`l possibly get trouble OFCOM are the current regulator

 

http://stakeholders.ofcom.org.uk/enforcement/spectrum-enforcement/law

[Cheeseweasel]

More info needed - is the display a large-scale public event, or a bunch of fairy lights rigged up in someone's house and garden? What is this FM equipment that you want to just plug in? From the OP, I can't tell whether you want to:

 

(1) Send audio wirelessly to avoid having to run cables e.g. to remote speakers

 

or

 

(2) Broadcast the programme audio so people can tune into it on their radios

 

If (1) and distances aren't too long then an in-ear monitoring system (IEM) with a number of receivers all tuned to the same frequency might be the way to go. If (2), then don't bother unless you're comfortable with the idea of running a pirate radio station

[James Aleksic]

For my christmas light display, I use a short range transmitter that I bought from argos (HERE). It's short range so is legal to use in the UK - and as long as it is on a clear station not being used by anyone else, I have found that you can still hear it clearly about 4/5 houses away (and over the road), which is as far as anyone is likely to need to be when trying to watch/listen to the light show. When I was showing people my display, it was as simple as tuning the FM radio built into their phones to the right frequency, and then I didn't have to put loud speakers outside and annoy the neighbours!

[Bobbsy]

I'll leave it to others to answer on the legalities since I'm 8 years out of date with UK regs but perhaps I can give a bit of background.

 

I visited my brother in Canada for Christmas a couple of years back and one evening we went on a "look at the Christmas lights drive".

 

I was surprised to find that it was pretty common for houses with elaborate displays to have a little sign up saying "tune to 104.3 (or whatever)" and if you did, you could stop for a couple of minutes to watch the lights cycle with some specific music. I have no idea if it was legal even in Canada (or what the copyright implications were either) but I have to say some of the displays were darn impressive.

[dbuckley]

LPFM (Low Power FM) is legal in many jurisdictions, including the USA, thus probably Canada, and New Zealand. It didn't used to be at all legal in the UK, but that may have changed in the intervening time since I've been there. Some more info on LPFM on Wikipedia.

 

The good folk at Planet Christmas have a lot of experience in which boxes are worth purchasing.

[paulears]

As we've said, these devices are legal to use here simply because their radiated power is extremely low, hence why my one in the van doesn't even have enough oomph to get more than a couple of metres, and struggles to get as far as the aerial on the roof! I can't see them being much use for people outside your house. Getting it high, and maybe taped to an upstairs window would be best case, but just try it and see.

[bruce]

As stated above, if it’s more than 50 nW ERP (yes, nanowatts) then it’s illegal to use in the UK without a license. Even though you can buy them on eBay....

[dbuckley]

50 nW ERP (yes, nanowatts)

 

Man that's mean. We're allowed the lower of 1W EIRP or 95 dBµV/m at 100m from the antenna. Which is enough for full quietened stereo reception with a car radio at that distance.

[scjb]

50nW is more than adequate for the designed purpose! ;)

[Emmien]

This is the one I was planning on:

 

http://www.amazon.com/0-5-Fail-Safe-Long-Range-Transmitter/dp/B003FO4UHW/ref=redir_mobile_desktop?ie=UTF8&refRID=0MXBVRRJDWZNMKXYBQTE&ref_=pd_aw_sim_23_2

It is the most popular for this application.

 

 

The guys in the US said it is definitely fine and they cannot fine you because it is "Fair use" to broadcast music for a Christmas light display, but I didn't believe them and laws are different here, of course.

 

 

I want people who watch my light show, to be able to tune into a frequency, advertised on my pixel matrix and a sign, and be able to tune in on their car stereo (Or possibly phones, but they need earphones normally, which people watching on foot may not be carrying) hear the music that accompanies my lights. Very similar to what James Aleksic mentioned.

 

I may put a small radio in a crate by the fence and tune it in, but there will be outdoor speakers for people on foot, at a "reasonable" level.

 

The in car transmitters tend to be very weak. I had a look and there are many power upgrade hacks but that is all too complicated.