Sorry, but the groundwave field in the AM broadcast band at a given distance from a transmit antenna is a function only of the power radiated along that path, other things equal.
An accurate NEC model shows those fields for any/all configurations of system hardware, and radiated power.
Suggest that those interested in this subject confirm my statements by referring to any college-level antenna engineering textbook (Kraus, Johnson-Jasik, Balanis etc), and download/become proficient with one of the free versions of NEC that are available (as a start).
There is no point in my constructing a Part 15 AM system to (re)prove a reality that has been proven many times in the past, going back many decades.
MRAM 1500 have you yet reported on the coverage from the remotely located ATU compared to a more typical antenna? Aside from being so exceptional where the rules are concerned, is it any better than the "normal way?"
Since Rich appears to want everyone to strictly adhere to the exact letter of the law in Part 15, then let's be REALLY strict. Perhaps he can do the following.
Point out exactly where in the rules it defines a Ground. And where it precisely states that the ground can't be elevated. Or even radiating. I don't want HIS interpretation of the rules. I want a strict quote directly from the rules.
And perhaps he can explain why even a few years ago, installations that were high in the air, grounded to a metal mast, were ruled complaint. Exactly how (and when) did the FCC change the Part 15 rules to disallow that. And what is the precise wording in the new rules that lets them do that.
I know for a fact that there are no definitions of a ground in the Canadian equivalent rules. I attempted to find a copy of Part 15 and could not, so perhaps he can help out.
Carl, regarding comparisons of the ATU to home built base loaded antennas, I can only say the ATU is much more user friendly as far as setup and use.
I did use the Talking House with my home built antennas and I can say subjectivly the range is better using the ATU. Unfortunately I never made a side by side comparison, performing an A-B comparison. I simply took one down, put the other up and said "Hey, this works better."
Previously I posted regarding moving the ATU from the roof to the ground and back to the roof. The coverage was terrible when ground mounted but part of that may have been some intermittent internal problems with the ATU.
I corrected one problem that was obvious. The reinforcement plate under the whip connection on the inside of the unit would move slightly when the wind blows. That would cause the whip connection to short to the ground connection dropping my signal abruptly. That was corrected but I also resoldered some questionable connections.
The end result, the intermittent is gone but the range also improved even without radials. Perhaps I will reinstall radials to see if I can obtain even better range.
If the home built had been easier to tune perhaps tweaking it to perfect resonance would have obtained the same result as the ATU. The ATU on the other hand requires simply turning a knob to obtain the highest reading on the ATU signal meter.
Some may argue the losses caused by the fine wire of the ATU coils result in greater losses compared to a home built loading coil of larger wire but you can easily put the ATU right on that sweet spot.
Your new title banner is very distinguishing....
Charter Member - National Association of Low Power Broadcasters
Thanks Carl but it was RFB that added a similar line to his signature and I thought "Sure, I'm one of those too!"
At the first round-table meeting of the NALPB, Lefty announced that participants of the first meeting will be the Charter Members.
That being the case I felt it appropriate to display affiliation with the newly founded NALPB.
"That being the case I felt it appropriate to display affiliation with the newly founded NALPB."
An endeavor which was long overdue and one necessary to have Part 15's voice heard, in all areas of the radio world.
There are those who will laugh, say its ridiculous, waste of time perhaps.
That was once said to the Wright brothers, Franklin, Tesla, even Einstein.
RFB
...but conveys the same message. I would like to make mine like MRAM's and RFB's, but I don't know how to make italics and bold type.
I still think my signature makes a statement. I'm proud and I'm a member.
There is no point in my constructing a Part 15 AM system to (re)prove a reality that has been proven many times in the past, going back many decades.
Brings to mind the phrase "Those who can't do, teach."
...a Part 15 AM system to (re)prove a reality that has been proven many times in the past, going back many decades.
How many times has a part15 AM system been proved using actual real world applications that it is incapable of performing considerably beyond the calculated theory which you present?
Never. Not once. Not ever.
Going back may decades my ass.
There is no such proven realities concerning Part 15 AM in existence as you imply and suggest.
"Many decades" What a joke.
The only "reality" proven is the emergence in the past several years.. ah, forget it.. RFB already said it a few post up, far more eloquently than I can.
I just cant help it Richard Fry; I get so pissed about you.. not because of what you present, but because you have no interest in the activity of experimenting in the hobby. Yet are determined to meddle with any and all those who do. But you personally will never touch it with a ten foot pole.
You say you have no agenda against.. then what is it you do got?
Oh yeah, you're just here to inform... despite the fact you have absolutely no hands on experience with part 15 at all.
Build and operate your own Part 15.. then talk.
ArtisanRadio wrote: Point out exactly where in the rules it defines a Ground. And where it precisely states that the ground can't be elevated. Or even radiating.
It is not the "ground" definition of the FCC, or of any individual that needs to be researched/vetted, but that of physics. FCC Rules don't define basic electrical units and terms; they are the definitions given by physics.
A perfect r-f ground maintains zero voltage regardless of how much r-f current flows into or out of that ground. This condition will be true for a perfect (zero loss) ground plane, and to a lesser extent for a ground plane consisting of the physical earth.
But a conductor attached to that ground plane does not have the same electrical characteristics along its length or height as the ground plane itself. Because of that it will radiate whenever r-f current is present on it. That current is provided by an elevated transmitter when its r-f ground terminal is attached to the top of that conductor, whether a short "ground lead" is used to do that, or not.
This added radiation from the entire conducting path from the transmitter to a true r-f ground is the basic reason why the FCC wants the total radiating length of a Part 15 AM antenna system not to exceed three meters.
Suggestions have been made about shielding the ground lead using coax cable, to prevent it from radiating. But even though the shield of the coax cable is connected to earth ground at its base, that will not prevent radiation from the cable. The link below gives an explanation of this.
http://www.w8ji.com/coaxial_line_and_shielded_wires.htm
... a few years ago, installations that were high in the air, grounded to a metal mast, were ruled complaint. Exactly how (and when) did the FCC change the Part 15 rules to disallow that. And what is the precise wording in the new rules that lets them do that.
No rule changes were necessary -- but in any case those systems were not grounded to the top of a metal mast, because that physical location is not at ground potential.
Part 15 Rules appear simple, but the operation of radio transmit systems is far from being simple.
...that for those "several decades", despite the fact about a long ground conductor in an elevated system would radiate, IT WAS NOT ANY CONCERN FOR DECADES!!
Not until around...oh 2006 to present. Now it is a big deal.
And the individual who instigated this sudden concern and forced the big brother hammer hand and crushed many a hard work, dedication and devotion to what they were doing has no intention of anything else, not even building a system, but to thump this and that on every table (post n thread) across any radio forum or blog that exists.
Anyone can verify that for themselves..Google is your friend.
I've already stated both sides of the coin. And all of that information can be verified by anyone. What has yet to be validated is your intent, other than the intent to provide information on charts and graphs, again to which IS valuable.
But unfortunately, it is lop sided, tipped scales, crooked picture on the wall. It lacks the supporting data of real world circumstance, which cannot be avoided in large systems or small, doesn't matter.
If you are indeed aware of "big boy" systems, and have installed, repaired, worked with etc etc, then you know DARN WELL that after EVERY installation AND every so often, PROOF OF PERFORMANCE measurements are done and documented IN THE REAL WORLD SETTING!! All required by those FCC rules and regulations. I know, I've done big boy systems too and all of them, including existing systems, have to prove their performance and document that information.
Adding: In 2008, KVOC AM 1230 was due for a measurement of the co-channel and splatter. I remember it well, as well as remember many other measurements of AM systems. What was most notable was the fact both I and the engineer with the piece of test gear to do that measuring, were standing outside in the real world about 200 feet from the frigging tower taking these measurements.
It was no simulation we were standing in.
Funny how manufacturers do the same thing. They catalog the unit's factory settings and performance, provide that data on an included sheet with the manuals etc, oh and this is the real kicker, they provide a BLANK sheet where the engineers who install said gear or systems, can MEASURE and document the system in comparison to the factory documentation.
Oh dear....that procedure is all around us! How can that be if everything is just left to simulations and "close to" real world input?
Now YOU tell US why that is and why they don't just set up, fire up and be done with it...eh?
There is no sense in trying to convince you to do anything. That is obvious you won't budge..stubborn like a mule standing on rail road tracks with the blunt end facing the oncoming disaster.
With that in mind...since your so resistive to what people are suggesting you do to supplement your sim data, just remember this, no one has to be convinced or intimidated or swayed or prodded into fearing working in the real world and actually doing something in that real world instead of just sitting in a comfy chair behind a computer screen.
It goes both ways ya know.
What a shame.
I hope someday you post about a real installation you put together and have a new set of charts and graphs for everyone.
RFB
If you are indeed aware of "big boy" systems, and have installed, repaired, worked with etc etc, then you know DARN WELL that after EVERY installation AND every so often, PROOF OF PERFORMANCE measurements are done and documented IN THE REAL WORLD SETTING!! All required by those FCC rules and regulations. ... Now YOU tell US why that is and why they don't just set up, fire up and be done with it...eh?
As you point out, licensed broadcast stations are required to make certain measurements after installation and before beginning to use those facilities for regular broadcasts.
I doubt that you are suggesting that this requirement should be made of Part 15 stations, also.
The FCC list of AM NOUOs has examples verifying what I have been writing about radiation from long conductors to an earth ground.
Their measurements of real-world Part 15 AM stations should be enough to convince most people, with no need for my hardware example.
Once again, an attempt to manipulate the circumstance (a post) by responding with an assumption won't work.
I am not implying anything about Part 15 being required to measure. You are implying that. I have not said anything about Part 15 having to proof their performance.
Can you show me where that is in my post?
Just read it for what it is as it is and not try to swing and ding things into your tunnel vision prospective, a habit you seem to have a hard time to break..amongst other things.
Dancing around the point isn't getting you anywhere today unfortunately. Nor has it gotten you anything in the past, as evidenced in the history books of archived forum threads spread across this wonderful world wide wire tap.
The point has been made, clearly and precisely and in as plain of English language as it can possibly be. Interpret it in any way shape or form as you wish. Just don't attempt to be the final say for everyone or the end all be all when you won't even join the club and put up a system to add to the simulated data.
You know the most strangest thing out of all of this is that one little thing you refuse to do..set up a system.
Your reason...it's in the simulations.
I hope those simulations help solve all your problems, virtual and real.
Adding: One thing at least, there ARE others who ARE doing real world setups, the most recent and documented one is Neils latest ground mounted system. Now that's as REAL as REAL can get!
Wouldn't you agree?
RFB
One thing at least, there ARE others who ARE doing real world setups, the most recent and documented one is Neils latest ground mounted system. Now that's as REAL as REAL can get! Wouldn't you agree?
Absolutely, and I referred favorably to Neil's outdoor setup earlier here.