Wich Part15 Give The Most Range??

Test are being made for the Talking House AM Transmitter on an indoor antenna.  I have a friend working on some antenna designs that are less than 3 meters including the ground and he has made some antennas before for different transmitters for AM and had reported some great range.  I'm actually looking into AM and I hope I'll get listeners for my station is Album Rock.  Here is something else you have to consider too. Temperature inversions.  After 6PM on FM you MUST check the frequency your transmitting on every 1 hr and then after 8PM every 1/2 hour.  If you cut over a distant station (No Matter If It Normally Does Not Serve Your Area you WILL get a complaint from a listener who knows he or she can pick up that distant station later in the day.  So no excuses you have to check that frequency evey hr after 6PM and after 8PM every 1/2 hour.  You do this by taking a highly sensitive Radio outside and listen for any Music or talk on that frequency.  If you hear a station its illegal for you to transmit again until the inversion is OVER again no excuses.  Licensed stations have the right away NOT part 15 stations.  If you don't want the hassle then AM is your only place to play.  Just as part 15:239 is important so too is the no interference law.  You cause interference your in violation of the FCC rules no if's and's or but's.

Any Other Part15 that you could 2 mile maybe even 4 miles or more??

Any Other Part15 that you could 2 mile maybe even 4 miles or more??

Commonly that is not possible, for useful listening to unlicensed AM/FM transmit setups actually complying with FCC Part 15.

What about part15s in other bands??

AM will generally give the most range but range is dependent on the receiver sensitivity and the ambient electrical noise.

My experience with AM is a range of just beyond 1 mile using a car radio in an electrically quiet surrounding and around 500 feet outdoors using a $15 portable receiver with an internal loop antenna. Inside my house at a distance of forty feet from the outside AM transmitter the signal is strong but not listenable due to buzz and interference. The noise is so bad that all AM stations are not listenable. Most of this noise is from light dimmers and CFLs.

Neil

This is not an easy question.

There are many factors that affect range with Part 15 FM, AM, Longwave or Shortwave.

But if you have an ideal installation, FM will go the shortest distance (10 - 800 feet), depending on the receiver sensitivity, receiver antenna, transmitting antenna height, etc.

As Radio8z posted, ranges of up to a mile and maybe more are possible with Part 15 AM.

I have no idea about Part 15 longwave.

Part 15 shortwave (i.e., the ISM band) might hold the most promise for longer distances.  You are allowed approximately 5 milliwatts ERP (the actual rules are measured with field strength, and that ERP is for an ideal dipole).  But there are no antenna restrictions, and that ERP is much more than you're going to get for Part 15 AM.  You're also in a part of the RF spectrum that is ideal for long range communication with ionosphere skip (although whether a 5mw signal would survive skip is open to question).

Not many people have experimented in the ISM band.  You could be one of the first.

Hello DJboutit.

It would be easier to give the best answer if we knew what you want to do.

Maybe you want to operate a radio station.

What kind of place do you have for a transmitter and antenna?

Do you have any previous experience withg broadcasting?

What will your programming be?

Many of us are already operating part 15 radio stations.

Hi Rich: Questions for you please ?

1) What software ( antenna & range plots ) do you use to get the information you put      on site ? Thanks.

2) Do you have any part 15 Am or Fm transmitters you test with ?

3) Have you design & built your own antenna(s) and do a physical test ?

4) Do you do a drive test and portable radio test to see what kind of range you get ?

5) Do you compare No. 3 & 4 with your computer software, What are your result ?

Thanks for any information please

station 8

1) What software ( antenna & range plots ) do you use to get the information you put      on site ? Thanks.

Mostly I use Numerical Electromagnetics Code (NEC), version 4.2.  In some cases I use software I wrote, myself.

2) Do you have any part 15 Am or Fm transmitters you test with ?

No, but that is not necessary to support the technical accuracy of the posts I make.  It is much easier using physics to predict accurate results from radiating antenna systems than it is to measure them, accurately.

Note that the FCC accepts the results of NEC analyses of the directional radiation patterns for new commercial AM broadcast stations, which when later measured, have been proven compliant with the radiation patterns/fields authorized by the FCC.

3) Have you design & built your own antenna(s) and do a physical test ?

Yes, for commercial broadcast applications.  No, for "Part 15" systems.

4) Do you do a drive test and portable radio test to see what kind of range you get ?

No, because "range" for Part 15 setups depends on too many unknowns, and would be inconclusive.

5) Do you compare No. 3 & 4 with your computer software, What are your result ?

No.

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If you want to learn more about my background, please visit my website at http://rfry.org

Hi Rich: Thanks for the information i want to give that software a try when i get a chance.

Station 8

Every few weeks some stranger like DJboutit signs in to ask a vague undetailed question which prompts everyone to jump to assistance by guessing what possible answers might be.

After the thread builds to a few postings it dies, and we never hear from DJboutit again.

Are we being seeded with fake inquiries?

It was said before that the FCC does monitor this forum is that not what I've read somewhere?  Being that said it could be possible that they want to see how much we really know about the subject of part 15.  I'm sure it has came their attention about our possible petition at some time or another.

Yes, I've read topics like this when searching for info, things start to get rooling and then the topic drops and you're left wanting more, and I wished they'd come back.

Perhaps DJboutit lost track of his topic? Don't get back for a day or two, and the list of topics on the front page doesn't include yours, then you have to try to find it in the different sections. I've urn into this several times where I had to try to remember what's section the post was in and go looking for it. I'm better at it now, but for someone who's new, that might be harder to do.

Maybe the site is turning over faster, especially with the ALPB and the different organizing efforts to improve part 15, so maybe a new front page post strategy would be nice, if it's possible. The number of hot topic posts in the list could be increased, doubled, or maybe have them stick around for a week after being posted to.

That's my idea, everyone would probably want something different.

I could see that The Legacy, almost like a poll to see which way the wind is blowing on a topic. You can note that this year there's been a lot of talk about AM improvement, with the FCC taking proposals about what should be done.

There are a number of detailed ideas thrown at the commission, from night power rule changes, allowing shorter antennas, to transmitters that vary their power with modulation to save energy. With that and LPFM on the air, lots of people must be studying this right now.