FM Transmitter legal limits

[fertsy]

I just bought one of these You are not allowed to view links. Register or Login

With the following Specs;
Features:

technical parameters?


      Frequency: 87.5-108.0MHz (custom-built frequency is acceptable
      Display mode: LED
      Frequency adjusting mode: “DOWN” & “UP”, short press for 0.1MHz scantling setting (long press for speed)
      Frequency saving mode: auto save, power-off memory
      Warp of modulate: ?±75KHz?100%?
      Sensitivity of modulate: 600mV
      Response of audio frequency: 100~15000Hz
      Audio distortion: ?0.2%?F=75KHz?f=1KHz?
      S/N ratio: ?60dB?1KHz 100%?
   Separate level of stereo: ?-60dB?200~15000Hz?
    Transmit power: 30mW
       Power supply:  DC12V


My simplest question, is this thing legal within FCC part 15. It appears to me that it is because from what I read you are allowed 100mW of transmitting power. The reason I ask is because I read this thing can range from .5 - 1 mile in range. I also understand that it cannot affect any other licensed broadcast.  Anyone have any experience or input?

Thanks,

Joe

[RJ]

Well the short of it is like this. There is more to the limit than the power of the transmitter. But 30 mw is low enough unless you did some serious work on antenna and other tweaks to up your Effective Radiated Power I would not worry about the FCC being after you.  Now the guys buying the 1 Watt and 5 watt units? They may be visited as that is enough to get noticed.

RJ

[fertsy]

Well thanks for the response RJ.

Glad you made it safely back from your trip.

The antenna I want to make is this one. You are not allowed to view links. Register or Login It looks supper simple. Now would you consider this major work on an antenna? I am worried about doing much less than this because I have read I will fry the transmitter with less or no antenna.

[RJ]

No, it should be fine. And if you exceed the limit it really only matters if you bother someone.

RJ

[dmaccole]

Fertsy:

RJ is right (isn't he always ) ... the baseline is whether someone complains. The first way to avoid that is to choose a good frequency, where you won't be overriding a licensed broadcaster's signal ... visit this web site, input your Zip code and it will tell you which are the unused frequencies in your area:

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The FCC has also said that the effective transmission of a Part 15-compliant FM transmitter is 200 feet ... here is the document (from 1991, it was *typed*):

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Best of luck.

\dmc

[fertsy]

hmm one mile seems much more than 200 feet. Lets just hope no one complains. Thanks for that vacant link that will help alot.

[coachers]

You could be in my boat.

 I just finished my "tune to 94.9" sign and just happen to click on the radio locator link on this thread.....GUESS WHAT! Now 94.9 is taken by a station just 3 miles from my house. Un-stinking believable! 
 Just a month ago it was wide open.

 

[fertsy]

Ouch very sorry to hear that.

[jnealand]

Another reason to use the radio signs that holidaycoro.com has available.  I used my with the halloween display and an very pleased with it.  If I need to change channels I just need to pull out the lights and repopulate.

[dmaccole]

GUESS WHAT! Now 94.9 is taken by a station just 3 miles from my house. Un-stinking believable! 
 Just a month ago it was wide open.

My first year, 2008, I did the RadioLocator thing, found everything fine, did plenty of tests ... during the daytime ... and all was well. But when I started running the show (at night, of course, when shows run) I found that after about two houses people stopped getting my signal and started getting a pirate radio station broadcasting from San Francisco. The station's signal reached farther at night.

It turns out that pirates use RadioLocator too.

Fortunately, if you were parked right in front of the house, my signal was fine. Also fortunately, the FCC escalated its enforcement on the SF pirates enough that they finally shut down.

\dmc

[fertsy]

This product looks like nothing more than pegboard. So I went straight to my garage to try it and of course it did not work. Is there anything that holds the lights in place or are the holes just the perfect size? Either way I think I might order one as the price is not bad at all.

Another reason to use the radio signs that holidaycoro.com has available.  I used my with the halloween display and an very pleased with it.  If I need to change channels I just need to pull out the lights and repopulate.

[Rainlover]

Fertsy,
I bought the coro radio sign and it is super easy to set up. The holes are perfect for minis. If I get a chance this weekend, I will post a video of the 2 messages it displays.
I also bought some coro mini-trees and they are cool too.

John

[jnealand]

This product looks like nothing more than pegboard. So I went straight to my garage to try it and of course it did not work. Is there anything that holds the lights in place or are the holes just the perfect size? Either way I think I might order one as the price is not bad at all.

Another reason to use the radio signs that holidaycoro.com has available.  I used my with the halloween display and an very pleased with it.  If I need to change channels I just need to pull out the lights and repopulate.

You can't use pegboard since it would not hold up in weather even if the holes were correct.  This is not an expensive sign,   and the holes are perfectly sized.  Since the shipping costs were relatively constant I bought two of them.  The second one will be populated with LED lights sometime this month.  btw the intensity of the one in the picture was set to a little less than half and it is still very readable.

[fertsy]

I ordered about an hour ago one radio sign and 6 coro 28" mini trees. Now you have me concerned about the full intensity of the lights, lol. With them "full on" is it readable to too bright? I will not have it hooked to a controller this year.