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Broadcast Low Power (Part 15 Compliant) at Dayton area HS football

S

SFIND

I have a question to some of you more-knowledgeable posters on here.

I run a local HS sports website and broadcast games on the internet. For this upcoming football season, I was looking to add a new feature of our website: broadcasting low-power on an FM signal from the stadium of the game we're broadcasting, so people at the game can listen along live.

I've been doing research on FCC's Part 15. I plan to purchase this FM transmitter and broadcast with a .1 watt signal.

Questions:
1) Does everyone think a .1 watt signal would be compliant with Part 15 (under 200 feet?).
2) Does anyone have any good suggestions of unused FM signals to broadcast on?

I'll be doing games in Montgomery, Miami, Clark, and Champaign Counties.
 
A legal FM part 15 transmitter wouldn't make it from one side of the field to the other unless the
fans all have some kind of dx-type yagi antennas with forward gain.

.1 watt ought to be legal, but is almost certainly too much power.

Part 15 FM is only truly legal if the signal is all faded away within 10 meters :-[

A legal part 15 FM transmitter won't even work acceptably in my cars for putting alt source audio on
the air. I must couple a wire from the device throuogh a door and wind a few loops of wire at the antenna mast.
Hardly worth the trouble.

If you use AM, a legal part 15 transmitter can be useful for a half-mile.
 
You can use .1 watt (100 milliwatts) on a Part 15 AM. The FMs are measured by field strength
rather than output power.

That said, it's a good idea. Check out the Community Radio board here on Radio-Info for more information on Part 15.

I have operated legal Part 15 stations on and off for a number of years and never had a problem.
 
SFind. Buy this. FCC Certified.

http://www.panaxis.com/pc-ACC100.html

I met a guy named Greg Stoddard in Princeton, IN that mounted one of these in a weather proof enclosure about 40 feet above his roof. You could hear the signal for at least a half mile in every direction in full quieting before the signal started to fade. The FCC has no rule against mounting the unit outside and up in the air and that will allow you to get more range.
 
William C. Walker said:
SFind. Buy this. FCC Certified.

http://www.panaxis.com/pc-ACC100.html

I met a guy named Greg Stoddard in Princeton, IN that mounted one of these in a weather proof enclosure about 40 feet above his roof. You could hear the signal for at least a half mile in every direction in full quieting before the signal started to fade. The FCC has no rule against mounting the unit outside and up in the air and that will allow you to get more range.
Click to expand...
As long as you don't have a ground wire attached to it, I believe that is true.
 
BobOnTheJob said:
William C. Walker said:
SFind. Buy this. FCC Certified.

http://www.panaxis.com/pc-ACC100.html

I met a guy named Greg Stoddard in Princeton, IN that mounted one of these in a weather proof enclosure about 40 feet above his roof. You could hear the signal for at least a half mile in every direction in full quieting before the signal started to fade. The FCC has no rule against mounting the unit outside and up in the air and that will allow you to get more range.
Click to expand...
As long as you don't have a ground wire attached to it, I believe that is true.
Click to expand...

This unit is FM. Not AM.

I don't want to get into a discussion about the semantics surrounding the proper way to ground a Part 15 AM transmitter that is FCC Type Certified at this time. We've dealt with this issue ad nauseum in the Community Radio Forum to the point that we've gotten nowhere with it.
 
Someone needs to make a formal petition for rule making to change part 15 to allow 100 mw FM, with some restrictions, of course. They force us to go through commercial coordinators for STL frequencies. How about making the 100mw part 15 fm stations do the same? They could partially help keep things coordinated and non-interfering.
 
FM is the corporate cash cow. No way they will raise the power level for legal unlicensed FM broadcasting.
 
William C. Walker said:
FM is the corporate cash cow. No way they will raise the power level for legal unlicensed FM broadcasting.
Click to expand...

That hasn't stopped them from doing anything before now. Docket 80-90, LPFMs, translators everywhere.

Why would saving the band start to matter now?
 
greg.hahn said:
William C. Walker said:
FM is the corporate cash cow. No way they will raise the power level for legal unlicensed FM broadcasting.
Click to expand...

That hasn't stopped them from doing anything before now. Docket 80-90, LPFMs, translators everywhere.

Why would saving the band start to matter now?
Click to expand...

Many in corporate broadcasting absolutely hate the thought of an unlicensed station getting out more than a few feet. There is a guy on the Community Radio Message Board of this forum by the name of Richard Fly (former engineer for Harris and a couple of big stations in Chicago I believe, now retired) that constantly harasses Part 15 broadcasters and especially users of Type Certified transmitters. He has also harassed a few of the manufacturers of these transmitters in an effort to get them to see things his way.

Sadly, his views are shared by many in the corporate radio world and while they give some ground on AM they won't with FM. There's a big difference between short spacing more stations into a crowded dial or adding licensed low power stations than increasing the power of Part 15 FM albeit on a miniscule scale. The key word here is "license" or lack thereof. That simple.
 
William..can you explain how, when the Panaxis xmtr is mounted outside on a mast with a fixed length antenna..clearly increasing the range...how is that legal when the FCC stipulations for part 15 FM are measured in meters? And not in power limits?

For AM, there are practically no restrictions on the "creative" ways additional range can be accomplished with "certified" 100mw Part 15 transmitters (Rangemaster, CHEZ) but when the FCC's definition of "illegal" on FM...has to do with the distance away from the antenna an FM signal can be heard rather than power..can these FM transmitters be certified? It seems that the certification would be applicable only if the transmitter was left inside, and sitting on a desk, but to place it outside for the purpose of increasing range has GOT to be a flag...and not really legal.

I really would like to have around 1/2 mile range on an FM signal, but I don't think it's really "legal"
 
Jeff, unless the rules were rewritten, I don't believe distance comes into play with FM either. To the worst of my knowledge all that matters is the Field Strength of the signal measured at a certain distance. There is nothing in the rules stating that you cannot mount the transmitter at a specific height either. I don't have the rules at hand right now but they may be on my website at www.lpam.net. Right now I am recovering from a couple of injuries sustained in a car accident (not my fault) and I am limiting my time on the web to a few minutes at a time. Otherwise I'd look this up for you myself.
 
Wow man..thanks for the reply especially in light if your injuries..hope you're okay.

I just see that the FCC will allow a certain field strength at a certain distance from the antenna. To me that translates to AM only being able to be listenable at a distance of something like 300 feet. Not really useable for a football game..more useful for homecasting to FM receiver in a house.
 
Jeff Laurence said:
Wow man..thanks for the reply especially in light if your injuries..hope you're okay.

I just see that the FCC will allow a certain field strength at a certain distance from the antenna. To me that translates to AM only being able to be listenable at a distance of something like 300 feet. Not really useable for a football game..more useful for homecasting to FM receiver in a house.
Click to expand...

Thanks Jeff. Nothing really serious though I have a couple of bruised ribs which are healing, whiplash which is also healing and a dislocated collarbone which is also healing but will take a couple of months to really become strong based upon past problems just like this.

Field Strength really does not apply for Part 15 AM (Only FM) except when a misinformed agent in one of the rogue field offices "thinks" it does. Prior to Fly showing up on the scene the FCC never even bothered with Field Strength for AM applications especially for transmitters which are Certified under Rule 15.219. That said, you only need to be certain that your antenna and ground don't exceed ten feet. Make sure the unit is grounded to meet UL regulations but the lead should be 18 inches and tied off to a surge arrestor or choke before the ground wire on the other end of the choke or surge arrest heads to the ground to a ground rod. That keeps it legal.

Most of the problems with this issue are in California and the Portland offices. Have not heard about one single problem with Detroit in this case or any other Field Office in the Northeast or Midwest when it comes to Type Certified units like the Talking House, Rangemaster, Chez Radio etc.
 
My previous post above was meant to be the FM standards according to the FCC. I mis typed AM for that. AM statins only need to be concerned with power outputs...FM part-15 on the other hand have a restriction as far as distance from the antenna goes..NOT power.

At least that what I take from this
 
Jeff Laurence said:
My previous post above was meant to be the FM standards according to the FCC. I mis typed AM for that. AM statins only need to be concerned with power outputs...FM part-15 on the other hand have a restriction as far as distance from the antenna goes..NOT power.

At least that what I take from this
Click to expand...

Just field strength applies here. However, FM is quite predictable when it comes to determining a potential broadcast distance with a certain field strength. The legal way to get around this is to do what Radio Greg did. Nothing in the rules states that you have to keep the transmitter at ground level or have to use it inside a building. Weather proof enclosure mounted up in the air like that will legally increase your range. So as long as you don't modify the transmitter or antenna on a Type Certified device, you will be fine.
 
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