FCC §15.219(b) limits the total length of the antenna, feedline and ground lead to 3 meters.
A review of Part 15 AM NOUOs issued from FCC field inspections shows that if an installation does not meet §15.219(b), then they revert to §15.209 to judge its compliance.
If that inspected system is producing a field intensity at 30 meters greater than permitted by §15.209, THAT becomes the basis for an NOUO, rather than non-compliance with any part(s) of §15.219.
So ultimately, those NOUOs are based on excessive field strength.
Whether or not it was intended by the FCC, it is very easy to exceed the field strength at 30 meters permitted by §15.209 when using a 3-meter, base-loaded, Z-matched antenna system driven by many/most commercial Part 15 AM transmitters.
Part 15 AM users generally have been left to sort this out for themselves.
What is the legal field
What is the legal field strength for AM at 30 meters for 15:209? We talk so much about FM field strength but not so much for AM.
Maximum Field in AM Broadcast Band, per FCC §15.209
Maximum Field in µV/m at a distance of 30 meters = 24,000 / (Frequency in kHz)
Example: at 1650 kHz it is 24,000/1650 = 14.5 µV/m (approx.)
Isn’t this what we already knew?
That if you meet FCC §15.219(b), FCC §15.209 is irrelevant? I haven’t done any scientific testing but I’m quite certain that all the popular Part 15 certified transmitters sold, in a fully compliant installation with FCC §15.219(b) will excede tha field strength of FCC §15.209, even with a pretty crappy installation.
So is this a matter of semantics? You violated FCC §15.219(b), but rather than getting a NOUO for that, you get one for violating FCC §15.209? Implying that even if you violate FCC §15.219(b), if your setup is crummy enough to meet FCC §15.209 you’re OK?
Are there examples where an operator meets FCC §15.219(b) but then gets busted for violating FCC §15.209?
TIB
Getting Busted
From Reply 3 (in italics):
… even if you violate FCC §15.219(b), if your setup is crummy enough to meet FCC §15.209 you’re OK?
That SHOULD be true.
Are there examples where an operator meets FCC §15.219(b) but then gets busted for violating FCC §15.209?
Unlikely.
If an FCC field inspector found that an installation was fully compliant with §15.219, that inspector would have no reasonable/legal cause to evaluate the performance of that installation with respect to §15.209, and/or to issue an NOUO if its radiated field at 30 meters exceeded the limit permitted by §15.209.
Rich is making it sound hazy.
Rich is making it sound hazy.. Like it’s questionable. – It’s not.
It’s simple and plain as day
There are two primary governing options of part 15 in relation to this matter:
~ One is based on field strength only with no limits on power or antenna length. ( 15.209 )
~ The other is based solely on power and antenna length, but has no field strength limitations. ( 15.219 )
You only have to conform to one rule or the other – not both – it’s two different alternatives of operation.
This option is clearly outlined in Section 15.215:
Additional provisions to the general radiated emission limitations.
(a) The regulations in §§ 15.217-15.257 provide alternatives to the general radiated emission limits for intentional radiators operating in specified frequency bands. Unlessw otherwise stated, there are no restrictions as to the types of operation permitted under these sections.
Those regulations spanning 15.217 thru .257 are all basically identical, except the specific frequency of operation… and our frequency range (510-1705) falls under the alternative rule 15.219.
It might still be possible to
It might still be possible to meet the field strength with a talking house AM transmitter and a 20 foot piece of wire with no ground. However putting that theory to real world testing or use could be questionable. I’d like to see some real test by using field strength to see what would happen.
A 20 foot piece of wire would
A 20 foot piece of wire would violate the 3 meter rule, grounded or not.
Oh.. you mean under 15.209..
Oh.. you mean under 15.209..
I don’t see what the point of trying is?
By the way.. you know there’s a brand new TH ATU on ebay right now? However they want $300 for it
The reason I would like to
The reason I would like to see this tested is because the range of a talking House AM transmitter on a piece of wire is far less than a Procaster. So with a home made antenna tunner and using a FIM made for AM an indoor installation could benefit by breaking the 3 meter rule and still keeping the field strength rule and still be compliant. it could be something that most folks have overlooked.
I know I’ve had a simular
I know I’ve had a simular discussion about this before.. The biggest factor with the major range difference between your talking house and the Procaster (or Rangemaster), is the outdoor install.. So if I understand you correctly you want to put your homade antenna tuner outside to gain that advantage. -I’m still lost on where the 20 foot wire without ground comes in.. To be honest, I don’t quite understand what your doing at all!
However, it seems to me there’s a simpler, and perhaps more effective way to extend your Talking House range.. (and forgive me if I’m compleatly missing your point)
I’ve never had a TH unit, but if I did, I would experiment with simply putting the unit in a waterproof box, wire a 8′ whip or a copper pipe for antenna, install it outside and ground it via ground rod(s) and run power and audio out to it.
This is after all basically what they are doing with the new TH outdoor units; ie: http://sales.talkinghouse.com/shop/item.aspx?itemid=46
I don’t understand why apparently, no one has already tried it.
(No subject)
I’m talking about an indoor
I’m talking about an indoor install for tenants who can not put up an outside antenna. It would have to be incognito thus a wire or something hidden from the landlord. This is why I suggested a 20 foot piece of wire with no ground. Hoping it would still meet the field strength rules and still be compliant. In most cases it probably would be.
Hmmmm.. Well, now I
Hmmmm.. Well, now I understand your situation..And your dead set on broadcasting legally right?.. I hate to tell you, but your not going to solve anything (at least not legally) by running a longer wire, regardless if you ground it or not.
There are only two ways to be legal:
15.219 which is a power and antenna length limitation. The power limit is 0.1 watt and the antenna system length limit is just under 10 foot. But there is no limit on radiation (range).
Or..
Part 15.209 which is a radiation limitation, which only allows you about 200 feet or so of range. You can run a wire as long as you want, but if extends your range more than a few hundred feet, then you wont be legal.
If your broadcasting with a Talking House, Rangemaster, Procaster, AMT, Grain Industries, or any other like part15 AM transmitter, the best option to operate legally is always under Part 15.219, because it will always provide you the best potential of a greater range.
I think your best bet is to install your Talking House unit the way the instructs say to do it, but try broadcasting on a different frequecy – usually the higher the frequency your broadcast is on gives better range.. Try setting the transmitter up in different locations around your apartment preferable by the wall that faces outside, and see if it makes a difference.. experiment with running your wire up or around a window, maybe you could run the wire up the window frame outside where it couldn’t be seen.. Try to keep the transmitter away from anything that might be interfering with your signal..
I don’t know, I’m just making suggestions… Maybe try grounding to a water pipe..
Uhhh.. Just realized our
Uhhh.. Just realized our discussion has drifted a bit off topic for this thread.. Way off.. I forgot what thread I was in.
Apologies
True
From Reply 6:
You only have to conform to one rule or the other – not both – it’s two different alternatives of operation.
True.
However, unlicensed installations that don’t meet either §15.219 or §15.209 are those most subject to FCC attention and an NOUO.
Reality
Followup to Reply 2:
Just to note that a field intensity in the AM broadcast band that is compliant with the §15.209 limit at 30 meters will be well below the ambient r-f noise level present at almost all real-world receive locations, and not very useful for “broadcasting.”