FM Transmitter vs Outdoor Speakers

[Orville]

Again, it falls into the category of "you can certainly do it..just (in this case) isn't legal from an FCC standpoint.."

As much of an issue is the fact that some may miss out on your audio depending on their particular FM radio.

Since digital has come into play, I think the FCC needs to revamp that and allow them to become open, legal frequencies for use for those that want to try and use them, hoping their audience has radios that can pick up those lower frequencies. My new 2012 replacement stereo I purchased for my vehicle still can, but don't know about others..

Why keep these old analog stations reserved for something they are no longer being {or can be???} used for?

[JBullard]

Since digital has come into play, I think the FCC needs to revamp that and allow them to become open, legal frequencies for use for those that want to try and use them, hoping their audience has radios that can pick up those lower frequencies. My new 2012 replacement stereo I purchased for my vehicle still can, but don't know about others..

Why keep these old analog stations reserved for something they are no longer being {or can be???} used for?

(quoting to preserve what this post is replying to)

The digital OTA tv stations still use many of the same frequency blocks (Channel 6 is one) as the old analog stations did. Except with digital several different tv signals are being transmitted in the same space that one analog station previously used.

So the entire channel 6 block of 82 to 88 is still very relevant and active in many markets.

[Liberty-Laser]

Sorry for diverging from the thread topic.

Every year I check with friends and neighbors both near and multiple blocks away. To-date - no interference of any type. I did have one neighbor down the road whose electronics blocked my signal for a short distance around his house. He has since moved and my signal is now clear.

My post was not meant to, nor would most people have interpreted it as quoting regulations or facts for the distance down to the nearest cm.. Up to that point all other statements were wildly off, I was trying to par it down. I apologize if I led anyone astray. Thank you to those who have studied the FCC regulations and corrected our errant ways. Having the facts is a good thing.

BTW: A few years ago I did call a local FCC rep to insure anything I was doing wouldn't be a major issue. Don't quote me on his name, but I'm sure it's Fred something.. but anyway, he said he brings his kids by every year to see my show.

[Guest Don Gillespie]

This gets discussed every year John said it perfectly in his last post "have you read them" if you haven't not a bad idea to read them, I call this comon sense, if you are broadcasting across the whole city you might want to rethink what you are doing, if you are broadcasting in front of your house you are more than likely going to be ok.

[JF1993]

I work at a drive in theater, and they use a radio transmitter to broadcast the sound out to the cars, because there are no longer speakers out there. I think it can broadcast a little over half a mile, but the drive in is surrounded by farm fields. Anyway the topic was about the use of outdoor speakers and/or radio transmitters... it sounds like we're all just a little off topic.

I'm still seriously considering the use of outdoor speakers over fm transmitters, and I do have a set of old computer speakers laying around that I might be able to convert into an outdoor speaker system. Other than that my local resale shops have plenty of old stereo speakers for $1 or $2 so either way I'll find a way to get my music out there this holiday season.

With all the FCC regulations, and other problems dealing with the fm transmitters it might be a while before I decide to deal with them. I appreciate all the pertinant information you guys have put in, and I think I've made up my mind to just run my show with a pair of outdoor speakers.

Thanks again,

JF1993

[JF1993]

Oh and another question about the fm transmitters. How does the FCC even regulate the rules. I know they are pretty strict on what and who can broadcast, but take my job for instance. Does the FCC actually drive out to places like that and monitor how far the signal is broadcasting, and what is being broadcasted? Or do they have some kind of giant antenna some where so they can pick up every radio signal in the area?

[dgrant]

I would imagine that they only investigate when they receive a complaint. Such as someone broadcasting over an assigned frequency and so on.

[Orville]

I would imagine that they only investigate when they receive a complaint. Such as someone broadcasting over an assigned frequency and so on.

What I find interesting about that statement, broadcasting over an assigned frequency, is I have heard LICENSED radio stations BLEED OVER and disrupt LOCAL close by stations I listen too. So if the FCC is going to come after me{us} if I{we} would happen to bleed over a licensed station unintentionally, what happens when a LICENSED station steps on another LICENSED stations broadcast? Would they, or do they, receive the same repurcussions as we would, or would theirs be much worse than our encounter with the men in black? Just something I've been curious about, since these licensed stations seem to do this on a constant basis, and they are still in operation. So do LICENSED stations get fined this as well or is it just "overlooked" as it's the way it is and just something that's part of the having higher powered transmitters {commercial stations only} and is considered acceptable for a licensed station? Again, just immensly curious..

But to try and remain on topic, I use both FM Transmitter and outdoor speakers in my display. Just the best of both worlds.

[Orville]

(quoting to preserve what this post is replying to)

The digital OTA tv stations still use many of the same frequency blocks (Channel 6 is one) as the old analog stations did. Except with digital several different tv signals are being transmitted in the same space that one analog station previously used.

So the entire channel 6 block of 82 to 88 is still very relevant and active in many markets.

Interesting to know this. Just know they contain nothing but bleed over, drift or static where I am. So I figured they had been decommissioned{?} from use in that range. But appears they are still relegated and being used in some areas.

Thanks for the info.

[dgrant]

I would think that if there was any bleed-over or harmonics and someone calls the FCC to complain, they probably come out and identify the offending broadcaster, then order them to fix their transmission source equipment. I'm no expert on the FCC but use to know some HAMS and back then, that seemed to be what would happen. Truly I do not know these days and I'm not licensed with the FCC in any way for anything. I am going to use my EDM for the first time this year and its set to the lowest power mode on it. I know it reaches to the street but I don't know just how far past that it goes at this minimum power setting which I think is 1mw.

[GaryM]

What I find interesting about that statement, broadcasting over an assigned frequency, is I have heard LICENSED radio stations BLEED OVER and disrupt LOCAL close by stations I listen too. So if the FCC is going to come after me{us} if I{we} would happen to bleed over a licensed station unintentionally, what happens when a LICENSED station steps on another LICENSED stations broadcast? Would they, or do they, receive the same repurcussions as we would, or would theirs be much worse than our encounter with the men in black? Just something I've been curious about, since these licensed stations seem to do this on a constant basis, and they are still in operation. So do LICENSED stations get fined this as well or is it just "overlooked" as it's the way it is and just something that's part of the having higher powered transmitters {commercial stations only} and is considered acceptable for a licensed station? Again, just immensly curious..

But to try and remain on topic, I use both FM Transmitter and outdoor speakers in my display. Just the best of both worlds.

You're comparing apples and oranges...a licensed station does not get fined if operating within their licensed parameters. Hearing two stations on the same freq does not mean one is in violation.

Operating within licensed parameters does not mean you can avoid the laws of physics and propagation...and hence, the situation you describe can occur.

But operating unlicensed, as everyone is doing in their displays, puts you at the bottom of the barrel..

And all the worry and teeth gnashing being displayed here can be avoided by just using some common sense (the FCC likes common sense), and understanding what the limits are (again, that would be 250 uV at 3 meters), and not going down the path of thinking you need to broadcast in a 3 mile radius.

[shfr26]

Well GaryM, I have to disagree with one of your comments

But operating unlicensed, as everyone is doing in their displays, puts you at the bottom of the barrel..

Is not the wonderful Wholehouse FM tranmitter legal and not needing a license??

[GaryM]

Its FCC Part 15 type accepted, but none of the operation we do, assuming you are operating under the guidelines of 15.239, requires a license.

[Orville]

You're comparing apples and oranges...a licensed station does not get fined if operating within their licensed parameters. Hearing two stations on the same freq does not mean one is in violation.

Operating within licensed parameters does not mean you can avoid the laws of physics and propagation...and hence, the situation you describe can occur.

But operating unlicensed, as everyone is doing in their displays, puts you at the bottom of the barrel..

And all the worry and teeth gnashing being displayed here can be avoided by just using some common sense (the FCC likes common sense), and understanding what the limits are (again, that would be 250 uV at 3 meters), and not going down the path of thinking you need to broadcast in a 3 mile radius.

I do not see how this is comparing apples to oranges, BLEED OVER IS BLEED OVER, no matter where it comes from.

if I bleed over, I can get fined for it. If a licensed station does the same, then they too, should be fined for it as well.

Should not matter if licensed or unlicensed, anyone bleeding over causing a station to be compromised to its listening audiience should not be permitted either.

Atmospherice conditions creating such effects at the time, well, no avoiding those and would be an acceptable perimeter, again, whether licensed or not, should not matter in the case of atmospheric, or weather disturbances that could cause the effect.

So I will have to disagree that this was, or even remotely is, comparing apples to oranges.

.

[Greg Young]

John B. was on the money. I don't have much time anymore to spend on the forums, but I am still very much around. Here is my post from last year, which was actually posted the year prior to that as well!

I had asked it be pinned, to save this issue coming up each year, but it never was.. sigh. Anyway here it comes, Greg:

For the benefit of the lurkers, I will comment (again, a semi yearly event it seems).

First off, I am not directing my comments at anyone who has posted they own the 1 watt units. I am directing this to folks who don't have a background in broadcasting, and may not fully understand what they can/should operate legally.

A 25mw with a whip antenna (telescoping one included with a unit like a Ramsey, etc) should easily provide a user with a 200 ft (radius) signal, unless the antenna is below grade level (ie in basement!). If you can't get a signal that range from 25 mw you have a problem with the unit/antenna (or you are broadcasting on the same frequency a local station is broadcasting on - which is not legal at any power level)

A one watt unit will send a signal that goes several miles, let me repeat that, several miles. It will not be limited to a few hundred feet, unless there is a major issue with the unit (ie harmonics, feedline mismatch, bad antenna resonance, etc, etc)

One watt is way, way beyond the limit allowed! (The actual limit under part 15 is based on received signal strength, but it works out close enough to a 200 ft radius, that you could sleep at night if that was the extent of your signal.)

If you pick a frequency in use, you will limit the effective distance of your signal, as FM receivers capture the stronger signal, which will "cover up" the weaker one. In the process of doing that however you will be interfering with signal reception of the licensed station on that frequency, and will get into trouble, should there be a complaint from a neighbor (and we all know how that can happen, as per neighbor relations postings on the forums).

If your 1 watt transmitter is dirty (ie if it can't run it inside the home without causing interference to other radios, etc), it has the potential to get you noticed very quickly.

Being an OO for the FCC for a number of years (dating back to my commercial FM broadcast days), I can assure you it takes very little time to track down a constantly transmitting (ie AM/FM, etc ) signal, esp with the doppler units that are available these days. A single complaint will result in a certified letter going out to the owner/operator of the device in question, that we call a NAL, which will require certain actions, as specified in the letter to be accomplished in an immediate time frame. Before the letter goes out, the location of the offending signal will have been confirmed, more than likely without you being aware of same.

We don't go knocking on doors, with the local sheriff, unless you have either not responded to the NAL and continue said illegal operations, or there is a more serious issue (ie interference with police, EMS, fire, ATC, etc). In those interference cases we go out with authorities, confiscate the equipment, and then send out the NAL.

I fail to understand several things:

1) Why do want to broadcast your signal beyond the area where folks can actually view your display?? There are enough local commercial FM stations that broadcast holiday music from Thanksgiving (or before these days) to December 26th. I find it hard to believe your community needs a lesser quality FM broadcast of holiday music, especially given the limited number of songs that most of us who synchronize our displays use during an evening show.

2) Why do some folks feel that certain laws apply to others, but not themselves?

3) Why would someone engage in a practice that risks an investigation, that could ultimately result in further legal restrictions, that might impact the vast majority (myself included) who are operating in compliance with legal requirements? We have seen that with the licensing of ATVs, snow machines, boats, etc that have all been put into place, based on the actions of a few. It is too easy to get restrictive laws passed. We don't need more!

I have asked these questions in the past without getting an adequate answer, other than to be simply accused that I was trying to intimidate people from pursuing their freedom of choice in purchasing and using said gear. That was never my intent. My intent then, and now, is simply to educate folks, so we can all get maximum enjoyment from our passion of holiday decorating, without running into legal hassles, or creating more issues with our neighbors, than many of our displays already do!

Can you imagine the impact, if we start to see complaints and investigations of part 15 transmitters, and it is determined the best way to deal with this issue, given limited manpower, is to simply pass legislation eliminating wireless FM/AM transmission under part 15? Far fetched you might say? Not at all. I can tell you first hand, this proposal has been previously discussed as an option!

Broadcasting is not a right, nor is it a freedom of speech. Those were arguments the radio pirates (aka bootleggers) used to try to convince folks they were in the right. The courts upheld the government's position each and every time those individuals legally challenged their fines, etc.

Sorry folks, but none of us own the airwaves. Use of the airwaves is a privilege, which in many cases requires licensure.

Part 15 devices do not require licensure, but they are limited as to how far their signals may radiate. In the case of any interference they cause to any other device they must be immediately shut down.

My point, to those that have not yet purchased their transmitters, is to carefully consider your options, and make an informed decision.

Greg

Edited September 20, 2012 by Greg Young

[Greg Young]

I do not see how this is comparing apples to oranges, BLEED OVER IS BLEED OVER, no matter where it comes from.

if I bleed over, I can get fined for it. If a licensed station does the same, then they too, should be fined for it as well.

Should not matter if licensed or unlicensed, anyone bleeding over causing a station to be compromised to its listening audiience should not be permitted either.

Atmospherice conditions creating such effects at the time, well, no avoiding those and would be an acceptable perimeter, again, whether licensed or not, should not matter in the case of atmospheric, or weather disturbances that could cause the effect.

So I will have to disagree that this was, or even remotely is, comparing apples to oranges.

.

Orv - if a commercial station is exceeding it's licensed bandwdith, that is a significant issue, and gets immediate attention by staff, once they become aware of it.

The other thing you need to consider before assuming they are exceeding bandwidth is to be sure it's not the selectivity of your receiver that is the issue.

It may simply be your receiver's front end is swamped by a very strong signal from a station that is closer to your location than the other station licensed on the frequency you hear the interference on.

It's always best to confirm with another receiver/location first. (ie take a drive in your car and see if you still have the issue)

If you still feel after checking with another receiver the issue exists, then I would suggest calling your nearest field office. If there is none in your immediate area, your phone book will have a 1-800 listing in the federal government section where you could lodge your complaint, or you could do it online at the FCC website.

Later,

Greg

[viennaxmas]

Just one additional comment - technically a "finished" unit needs to have FCC sticker on it to be operated (like pretty much any other electronic device). There are a lot of transmitters around which do not have this. This label is intended to certify that the transmitter is not interfering with other equipment and that the transmitter can handle a certain amount of interference. A different story is "self built" transmitters, they do not require this FCC seal but it is the operators responsibility to ensure that it does not interfere. This is the reason why a lot of transmitters sold for our purpose are coming as kit and require assembly.

The second important piece is the antenna - I have seen a lot of posts in other forums with tips to modify the antenna. As Greg pointed out the antenna plays a major role... for various resons:

A badly tuned antenna creates reflective power into the transmitter amplifier which worst case can burn out the transmitter. In addition the coverage area of the transmitter is strongly dependend on the antenna. In my first year of having a transmitter, I had used a WIFI antenna out of my basement (the original antenna was broken) and barely got 100 ft at about 50% of the maximal power. Last year I came up with the idea of mounting a tunable quarterwave with ground plane under my roof (this is an antenna commonly used for commercial low power FM stations)... at 20% of the maximum transmitter power, I did get almost 2 miles in the inital test. I had to add a bunch of delta splitters and dummy loads to get it back down to acceptable levels (close to 200ft).

The 200ft range is not listed in the FCC regulations, however based on the 250 microvolts/ meter at 3 meters in average conditions with an average receiver, the range ends around 200ft. However this is strongly dependend on the conditions, down to humdity, air pressure and temperature. Unfortunately not many of us have the luxury of a field strength meter (or the possibility to borrow one). This is where the recommendation of only using transmitters approved for FCC Part 15 comes from. These transmitters are set up and tuned not to exceed the 250 microvolts/ meter at 3 meters.

In the end all of us pushing for everyone to put a little thought in what we all do are simply concerned about everyone staying safe and out of trouble.

[GaryM]

I do not see how this is comparing apples to oranges, BLEED OVER IS BLEED OVER, no matter where it comes from.

if I bleed over, I can get fined for it. If a licensed station does the same, then they too, should be fined for it as well.

Should not matter if licensed or unlicensed, anyone bleeding over causing a station to be compromised to its listening audiience should not be permitted either.

Atmospherice conditions creating such effects at the time, well, no avoiding those and would be an acceptable perimeter, again, whether licensed or not, should not matter in the case of atmospheric, or weather disturbances that could cause the effect.

So I will have to disagree that this was, or even remotely is, comparing apples to oranges.

.

Greg did a good job of further explaining, and if you read my first comment "...if operating within their licensed parameters..", you'll hopefully understand.

But to try to draw comparisons and suggest unlicensed part 15 operators should be looked at in the same way as a licensed operator is, as i said, apples to oranges.

I'm done here..not worth wasting anymore time on the topic...Greg and John, in a couple posts, told you all you need to know.

[dusty72]

Thank you all for your information...There is alot of useful material here and alot of questions that are answered.