Same Old Same Old About FCC Regs.

[Rattan]

In some cases the FCC has cited both 15.209 and 15.219 in issuing an NOUO based on excess field strength and excess transmitter power -- see http://www.fcc.gov/eb/FieldNotices/2003/DOC-278979A1.html

I would tend to disagree with that interpretation of the NOUO. To quote from the NOUO you refer to:

The field strength of the signal on frequency 1700 kHz was measured at 168.8 microvolts per meter (uV/m) at 265 meters, which exceeded the maximum permitted level of 14.12 uV/m at 30 meters for non-licensed devices set out in Section 15.209 of the Rules, 47 C.F.R. S: 15.209. Further, the station's operation did not comply with the alternative operating requirements for stations operating in the band 510-1705 kHz that are set out in Section 15.219 of the Rules, 47 C.F.R. S: 15.219. Specifically, the agents measured the input power to the final radio frequency stage and found it to be 1200 milliwatts, which exceeded the maximum power level of 100 milliwatts permitted under Section 15.219(a). Thus, this station is operating in violation of 47 C.F.R. S: Section 301.

It appears that the station was checked under 15.209, and when it was over that limit, they then checked to see if it was possibly compliant under 15.219. In logic terms, this is apparently an OR situation rather than an AND situation. It was given every possible chance under the rules.

If compliance under both sections was required/expected, then there would have been no *need* to check for 15.219 compliance, since the station would already have been in violation. Such would be the case if it had been a part 15 FM that exceeded the allowed 250uV@3m, since there is no alternative provision for part 15 operation in the FM band.

That they checked for possible compliance under 15.219 would indicate that 15.219 is considered a viable alternative to 15.209 rather than that *both* 15.209 and 15.219 compliance are required for part 15 operation on the AM BCB.

This sort of case has been discussed many times, and there is no indication from this NOUO that the FCC has suddenly changed enforcement policy. This is consistent with what we have usually seen in the relatively few FCC actions that might have been intended as (or hoping to pass as) AM BCB part 15 operation. So I am unclear on what this point of the current debate is trying to achieve?

Daniel

 

[Goat Rodeo Cowboy]

So I am unclear on what this point of the current debate is trying to achieve?

One guy put in a career working with the manufacturers of "heavy iron" for the broadcast industry. This was life in a world where never, never, ever did you want a reputation that your equipment did not meet every last possible requirement of the rules. No broadcasters would want to buy equipment from a manufacturer that might leave him facing a fight with the FCC over a rules violation.

The other guy apparently is a dealer for Part 15 transmitters and an operator of at least one Part 15 station. He lives and operates in an "inverse universe" from the other guy. Every day may be one more day that you have to prove that what you do is actually legitimate and legal.

Two different mindsets. Looking into the telescope from opposite ends.

 

[rfry]

In some cases the FCC has cited both 15.209 and 15.219 in issuing an NOUO based on excess field strength and excess transmitter power -- see http://www.fcc.gov/eb/FieldNotices/2003/DOC-278979A1.html

I would tend to disagree with that interpretation of the NOUO.

Don't quite understand your comment, as the statement I posted is, in fact, what the FCC did, isn't it?

That they checked for possible compliance under 15.219 would indicate that 15.219 is considered a viable alternative to 15.209 rather than that *both* 15.209 and 15.219 compliance are required for part 15 operation on the AM BCB.

And I agree with you. Note that a Part 15 AM setup that is functionally legal under 15.219 can produce much higher fields than defined by 15.209.

High enough, in fact, to be measured accurately by a suitable field strength meter (Wm Walker, please note).

//

 

[Rattan]

Ok, Rich. I obviously misunderstood.

I do not know the FIM, obviously. But logically even a good car radio at that range could pick up an intelligible signal from a *compliant* part 15 AM system. 265 meters is only about 870 ft. It also stands to reason that a tuned amplified specialized instrument for measurement of relatively small fields could do better than a car radio.

No instrument is perfect, of course. There is always a margin for error, even though it may be small with very good instruments.

I must admit that I find the situation Mr Walker explains quite puzzling. If the transmitter is turned down to zero, then how could there be anything to detect?

I would add one possibility to the ones Mr Walker lists.. If the FCC field agent's meter was picking up some other station that happened to be on the same frequency, then they might have mistakenly been taking that reading for his. I noted from the pictures and descriptions that the FIM (assuming that's what was used) has a headphone output for hearing what is in the frequency being checked. Do you know if they confirmed that it was indeed your program material? If the meter is sometimes used for checking stations 100 miles away as Rich has explained , then perhaps something was coming in via skywave or a distant station that just wasn't normally strong enough to have listeners in the area but still strong enough for the meter to detect may have been the source of a mistaken reading?

That's the only logical explanation that comes to mind given the circumstances that would allow for the instrument actually being useful *and* an honest mistake in it's use.

Actually, I can think of one more possibility, but it would be unlikely as well as unpleasant. If someone in the area disliked Mr Walker's station enough that they were attempting to "jam" his signal with another transmitter. That could account for another signal on the same frequency the the meter would pick up and the possibility might seem so unlikely that even the best FCC technician might not think to check for it.

Daniel

 

[Rattan]

Goat Rodeo Cowboy - Yes, now that you've explained it that way, I see it. Thank you.

Though they may be on opposite ends of the telescope, I have no reason at this time to doubt that they are both honestly presenting what they see as the truth of the matter. That's part of what makes this debate so highly interesting. Much of it seems to have moved to being around the question of if it is possible that an FCC reading could be enough in error for a part 15 station to wrongly get in trouble or be shut down.

Certainly an important enough matter to anyone with any interest in part 15, and this is being one of the more interesting debates I've seen on the forums lately.

Daniel

 

[WCWalker]

Ok, Rich. I obviously misunderstood.

I do not know the FIM, obviously. But logically even a good car radio at that range could pick up an intelligible signal from a *compliant* part 15 AM system. 265 meters is only about 870 ft. It also stands to reason that a tuned amplified specialized instrument for measurement of relatively small fields could do better than a car radio.

No instrument is perfect, of course. There is always a margin for error, even though it may be small with very good instruments.

I must admit that I find the situation Mr Walker explains quite puzzling. If the transmitter is turned down to zero, then how could there be anything to detect?

I would add one possibility to the ones Mr Walker lists.. If the FCC field agent's meter was picking up some other station that happened to be on the same frequency, then they might have mistakenly been taking that reading for his. I noted from the pictures and descriptions that the FIM (assuming that's what was used) has a headphone output for hearing what is in the frequency being checked. Do you know if they confirmed that it was indeed your program material? If the meter is sometimes used for checking stations 100 miles away as Rich has explained , then perhaps something was coming in via skywave or a distant station that just wasn't normally strong enough to have listeners in the area but still strong enough for the meter to detect may have been the source of a mistaken reading?

That's the only logical explanation that comes to mind given the circumstances that would allow for the instrument actually being useful *and* an honest mistake in it's use.

Actually, I can think of one more possibility, but it would be unlikely as well as unpleasant. If someone in the area disliked Mr Walker's station enough that they were attempting to "jam" his signal with another transmitter. That could account for another signal on the same frequency the the meter would pick up and the possibility might seem so unlikely that even the best FCC technician might not think to check for it.

Daniel

Rattan. The frequency I was using was completely clean. Nothing on it in mid morning during the time of their visit. And houses in that neighborhood are spaced apart by about 50 feet on two sides, over 100 to one side and then a half mile to the back. Nobody was jamming my frequency or using it either. I had my own radio nearby and set to my frequency to monitor my station and when I had my transmitter turned down to zero, there was nothing else coming in.

My two theories are the ONLY possible explanations as to why they could not get an accurate reading. Either the FCC agent was lying or their FSM cannot accurately read low power AM signals. I sincerely doubt it was a case where the agent did not know how to use or accurately interpret the readings on the unit. And since I was told by people ABOVE the local FCC Field Office that their FSM's cannot accurately read these LPAM signals, they do use the 100 mw power limit for determining the legality of a transmitter. And again, other people that I know that are involved in Part 15 AM have been told the very same thing by the FCC as well.

 

[Tom Wells]

OK, let's consider the case that the FIM was not very selective, and being influenced by a station on an adjacent frequency.
In my case, I'm on 1620. WONX Evanston IL is on 1590, and only about 2 miles away. It throws a lot of splatter from
overmodulation, and even my car radio with a tuned RF preamp stage gets swamped by the signal while still pretty close to my house.
Unless we find out exactly what meter was being used, and whether it was tuned properly, there is no way of knowing what
the meter was measuring. Did you see the FCC agent using headphones to ascertain that he was on your signal?
What's the RF noise environment like nearby, could a neighbor's lamp dimmer have been on, was the agent out in "the clear" when
making this test? Was he under a power line, etc? If you turned down the power, and he saw no change, there was definitely
something wrong somewhere, somehow. Do you have a situation where there is a strong adjacent or 2nd adjacent?

Next, do these meters use passive or "active" RF amp selectivity? All active designs are subject to influence from
unintended signals and noise unless preceded by high-Q passive tuned circuits and shielded like a military radio or old fashioned auto radio
with a steel case. I presume a successful test MUST be accompanied by a test calibration measurement on a known "empty" frequency
or frequency IN USE, to see if the meter measures accurately a known signal strength in that vicinity. Any good test has a control procedure to validate the test equipment's results. Can we agree on this, and does anyone know if such a test is part of the
FCC's procedure for making measurements?

 

[WCWalker]

Tom. I was using 1700 and at that time, ten years ago, there was nothing even on the X band in this region. Nothing. And being 25 miles from downtown KC there are no transmitter towers nearby or at least not at that time. Not even a Cell tower. Nothing.

No power lines in that part of the town because they are all buried. The houses are spaced apart reasonably well and there was nothing causing any kind of RF nearby or interference.

The FCC engineer did use headphones.

I'm certain that it can be easy to identify the FIM that was used at that time because I am going to have to believe that it would be standard issue for every Field Office circa 1999.

 

[Tom Wells]

Is or was there a local on 850 that could have been throwing a 2nd harmonic your way?

Other local signals could be possibly mixing and throwing an image on 1700.

Did the agent have a chart of such locals handy, and spend some time looking at the numbers, rubbing his chin, or otherwise
mentally trying to figure out how his meter was not responding to a 100% change in your power?
That's the key item of info: No change shown in the test instrument for a known large change in the experimental value.
If it were anything I had to work on, I would invalidate the instrument's results until a reason were discovered.
If you can't trust it, it's either broken, (not just miscalibrated), the wrong device for the job, or improperly applied.

Did he have a pocket calculator to help him figure out image possibilities?


Did the agent still hear your audio when the power was at zero?
I would have asked him to identify the program material being aired at 0% percent before I would accept such a claim as possible.
I know when I turn my power down to zero, I can't copy anything 3 feet away from the TX.

 

[rfry]

And since I was told by people ABOVE the local FCC Field Office that their FSM's cannot accurately read these LPAM signals, they do use the 100 mw power limit for determining the legality of a transmitter.

Maybe it boils down to this. The maximum field allowed at a distance of 30 meters under Part 15.209 ranges from about 44 microvolts/meter at 540 kHz to about 14 microvolts/meter at 1700 kHz.

While the FIM-41 can accurately measure MW fields as low as 10 microvolts/meter, the r-f noise in the AM broadcast band is considerably higher than those values. The only way to accurately measure such a weak radiated field is to use a shielded environment, including anti-reflection surfaces that absorb radiation not launched directly by the transmit antenna. There are commercial test labs capable of doing this, but obviously it is not possible in an outdoor environment.

So the FCC is correct in saying that they could not confirm that someone's Part 15 AM installation actually meets 15.209.

HOWEVER, the fields radiated by a Part 15 setup operating under 15.219 can be much higher than allowed under 15.209. The chart linked below shows that even for a Part 15 AM that is functionally compliant under 15.219 (the green trace in the plots), the field at 100 meters is about 1 millivolt/meter. That is 71 times the field allowed under 15.209 for 1700 kHz, and at over three times the distance.

A field of 1 millivolt/meter is well above the ambient r-f noise level in most locations, and therefore can be measured accurately by a suitable meter. And the fields from "elevated" systems are greater still due to radiation from the conducting path to whatever is serving as the r-f ground (typically something buried in the earth).

The FCC can still issue an NOUO based on 15.209 when they measure a field that is far in excess of what 15.209 allows (like the 7.4 millivolt/meter field they measured from the Flagstaff station).

But a blanket statement that the field of a Part 15 AM setup can never be accurately measured is absolutely incorrect.

http://i62.photobucket.com/albums/h85/rfry-100/Part15AMSystemComparison.gif

 

[WCWalker]

Fry. It boils down to this. Maybe nothing...

That Flagstaff station was running OVER ONE WATT. Not 150 mw, not 327 mw, not 489 mw. It was not a Part 15 AM station and certainly not a Hamilton Rangemaster transmitter. According to my own station engineer and Keith Hamilton it is impossible for a Rangemaster to develop one watt of power and in fact, nothing even close to it with the current design and components. Unless someone literally took the guts out of the Rangemaster box and rebuilt it with different components, it was NOT a Rangemaster Part 15 AM transmitter or for that matter ANY other Type Accepted unit.

And yes, my blanket statement does apply. It is NOT possible for these FIM's to accurately read a power level of a few mw or even a hundred or thereabouts. That is the very reason why 15.219 was created. The FCC approved Type Acceptance for units that met their criteria and it simplified the fact finding missions of agents in the field. The ONLY way to get a fairly accurate reading of field strength of a Part 15 AM transmitter is to physically remove it from its location and send it to an FCC lab for testing. The FCC does not want to be bothered with the hassle and again, hence the Type Acceptance process to keep things simple.

And in my case, why did the folks in DC tell their subordinates at the KC Field Office to put my station back on the air? Do you have an answer for that one?

 

[WCWalker]

Is or was there a local on 850 that could have been throwing a 2nd harmonic your way?

Other local signals could be possibly mixing and throwing an image on 1700.

Did the agent have a chart of such locals handy, and spend some time looking at the numbers, rubbing his chin, or otherwise
mentally trying to figure out how his meter was not responding to a 100% change in your power?
That's the key item of info: No change shown in the test instrument for a known large change in the experimental value.
If it were anything I had to work on, I would invalidate the instrument's results until a reason were discovered.
If you can't trust it, it's either broken, (not just miscalibrated), the wrong device for the job, or improperly applied.

Did he have a pocket calculator to help him figure out image possibilities?


Did the agent still hear your audio when the power was at zero?
I would have asked him to identify the program material being aired at 0% percent before I would accept such a claim as possible.
I know when I turn my power down to zero, I can't copy anything 3 feet away from the TX.

Tom. 850 in Denver won't create a 2nd harmonic from 600 miles away. And if there was a 2nd harmonic on that channel I could have picked it up on my radio. I was using a GE Superradio 3 and a Sony 7600G to monitor my station. Both have excellent AM tuners.

No audio was detectable after the power level was set to zero. I do seem to recall that he had a calculator on hand but I can't recall whether or not he was using it. He had another guy with him and I was talking to him while the guy with the FSM was playing around.

Yes, the findings were invalidated. I turned off my transmitter after the guy could not figure out why he could not get an accurate reading. Then a few hours later I got a call back from their Supervisor telling me to go back on the air because they were unfamiliar with the Part 15 rules governing these transmitters.

 

[rfry]

That Flagstaff station was running OVER ONE WATT. Not 150 mw, not 327 mw, not 489 mw. It was not a Part 15 AM station and certainly not a Hamilton Rangemaster transmitter.

Then why did you post that they were using a Rangemaster shortly after the NOUO was issued?

It wouldn't take over one watt of transmitter power to generate the field that the Flagstaff station was cited for. A Rangemaster or any other transmitter of its power could produce the 7.4 mV/m field measured at 122 meters from the Flagstaff station by the FCC. All it takes is to mount the transmitter and 3 meter whip on top of a 10 or 11 meter grounded metal support structure, and connect the transmitter ground terminal to the top of the supporting structure.

This can be seen in the blue trace in the chart at http://i62.photobucket.com/albums/h85/rfry-100/Part15AMSystemComparison.gif , which is based on only 30 milliwatts from the transmitter.

And yes, my blanket statement does apply. It is NOT possible for these FIM's to accurately read a power level of a few mw or even a hundred or thereabouts.

I've given you ample information showing that they can for stations operating under 15.219. You refuse to accept it, and so be it -- but hopefully others accept it.

And the FCC knows that it is possible, seeing as they made such a measurement in Flagstaff.

And in my case, why did the folks in DC tell their subordinates at the KC Field Office to put my station back on the air? Do you have an answer for that one?

There is not enough validated information available about what you say happened to make a determination.

//

 

[WCWalker]

A Part 15 AM transmitter like the Rangemaster cannot, I repeat CANNOT produce a power level of 1200 mw. That is power level stated in the NAL. Again, proof positive that you cannot get an accurate reading from these FSM's at these low power levels.

I've illustrated time and again over the years that my points are valid and that the FCC has not been able to accurately get field strength readings for several of these stations.

You just don't get it and you keep spewing the same old rhetoric over and over again.

And I'm pleased to hear that you don't have an answer for why the FCC permitted me to go back on the air as well as others that have had the same issue. It just shows you are incapable of critical thinking if the answer cannot be found in a book.

 

[rfry]

A Part 15 AM transmitter like the Rangemaster cannot, I repeat CANNOT produce a power level of 1200 mw. That is power level stated in the NAL.

Could you please tell us the source of your "facts" about this subject?

The text of that NOUO (not NAL) is pasted below. Please note that no mention is made in it of the power level of the transmitter in this system.

As I have shown, a Rangemaster on an elevated mount could produce the field intensity measured by the FCC at the distance they measured it.

Here is a link to this NOUO on the FCC web site, so that you can verify that I did not edit it.

http://www.fcc.gov/eb/FieldNotices/2003/DOC-260037A1.html

//

FEDERAL COMMUNICATIONS COMMISSION

ENFORCEMENT BUREAU
Western Region

San Diego Office
4542 Ruffner Street, Suite 370
San Diego, CA 92111

July 13, 2005

Overdrive Broadcasting
Flagstaff, Arizona 86001

NOTICE OF UNLICENSED OPERATION

Case Number: EB-04-SD-198
Document Number: W200532940002

The San Diego Office received information that an unlicensed
broadcast radio station on 1650 kHz was allegedly operating in
Flagstaff, Arizona. On May 17, 2005, agents from this office
confirmed by direction finding techniques that a radio
transmitter operating on the frequency 1650 kHz was located on
West University Street, Flagstaff, Arizona. The Commission's
records show that no license was issued for operation of a
broadcast station at this location on 1650 kHz in Flagstaff,
Arizona.

Radio stations must be licensed by the FCC pursuant to 47 U.S.C.
§ 301. The only exception to this licensing requirement is for
certain transmitters using or operating at a power level that
complies with the standards established in Part 15 of the
Commission's rules, 47 C.F.R. §§ 15.1 et seq. Your operation on
frequency 1650 kHz was measured at 7,400 microvolts per meter
(µV/m) at 122 meters. This exceeds the allowable unlicensed
limit of 14.5 µV/m at 30 meters established in 47 C.F.R. §
15.209(a). Thus, this station is operating in violation of 47
U.S.C. § 301.

You are hereby warned that operation of radio transmitting
equipment without a valid radio station authorization constitutes
a violation of the Federal laws cited above and could subject the
operator to severe penalties, including, but not limited to,
substantial monetary fines, in rem arrest action against the
offending radio equipment, and criminal sanctions including
imprisonment. (See 47 U.S.C. §§ 401, 501, 503 and 510).

UNLICENSED OPERATION OF THIS RADIO STATION MUST BE DISCONTINUED
IMMEDIATELY.

You have ten (10) days from the date of this notice to respond
with any evidence that you have authority to operate granted by
the FCC. Your response should be sent to the address in the
letterhead and reference the listed case and document number.
Under the Privacy Act of 1974, 5 U.S.C. § 552a(e)(3), we are
informing you that the Commission's staff will use all relevant
material information before it to determine what, if any,
enforcement action is required to ensure your compliance with FCC
Rules. This will include any information that you disclose in
your reply.

You may contact this office if you have any questions.

William R. Zears Jr.
District Director
San Diego Office


Attachments:
Excerpts from the Communications Act of 1934, As Amended
Enforcement Bureau, "Inspection Fact Sheet", July 2003

 

[WCWalker]

You threw me a curveball with two different NOUO's. Apparently the 1200 mw reading was from a station in the Philly region.

Regardless, it does not mean that either of these readings is accurate.

Keith Hamilton designed the unit so that it would not be capable of being modified with its existing components to achieve a high power level. My own station engineer confirmed this after he examined the schematic and the unit itself.

 

[rfry]

You threw me a curveball with two different NOUO's. Apparently the 1200 mw reading was from a station in the Philly region. Regardless, it does not mean that either of these readings is accurate. etc.

Mr Walker: Are you seriously suggesting that you and your own "station engineer" believe that the FCC is incapable of measuring the field intensity values they report in Part 15 AM NOUOs, within practical limits?

Note that the accuracy of calibrated, professional-grade MW field intensity meters typically is within 5% of the true value.

Also note that the measurements reported in these FCC NOUOs were far above the value where a 5% error would have any influence on the basis for the NOUO.

//

 

[WCWalker]

You threw me a curveball with two different NOUO's. Apparently the 1200 mw reading was from a station in the Philly region. Regardless, it does not mean that either of these readings is accurate. etc.

Mr Walker: Are you seriously suggesting that you and your own "station engineer" believe that the FCC is incapable of measuring the field intensity values they report in Part 15 AM NOUOs, within practical limits?

Note that the accuracy of calibrated, professional-grade MW field intensity meters typically is within 5% of the true value.

Also note that the measurements reported in these FCC NOUOs were far above the value where a 5% error would have any influence on the basis for the NOUO.

//

Yes. And I heard that first from the FCC itself followed by other people that run Part 15 AM stations.

 

[WCWalker]

The following perfectly illustrates my point that they may not be able to accurately read these LPAM signals.

Note the oops in this NOUO. The FCC used radiation limits for Part 15 FM when reading his signal.

http://www.fcc.gov/eb/FieldNotices/2003/DOC-272448A1.html

Part 15 FM rule below.

http://edocket.access.gpo.gov/cfr_2002/octqtr/47cfr15.239.htm

 

[rfry]

The following perfectly illustrates my point that they may not be able to accurately read these LPAM signals.
Note the oops in this NOUO. The FCC used radiation limits for Part 15 FM when reading his signal.

No, they measured the field intensity at 23.6 millivolts/meter within the error range of their instrumentation (maybe 5%). They just cited the wrong limit when they wrote up the NOUO. That doesn't invalidate the measurement, itself.

Under 15.209 this station is allowed 14.8 microvolts/meter at a distance of 30 meters, so this setup as measured at 75 meters would fail the 15.209 limit by an even greater margin than it failed the Part 15 FM limit.

Note that a MW field of 23.6 millivolts/meter is an extremely strong signal. The chance of co-channel interference and/or local r-f noise even slightly affecting the accuracy of a suitable field strength meter when measuring this field value is essentially zero.

The effective radiated power (ERP) needed to generate 23.6 mV/m, 75 meters away is less than 40 milliwatts. That ERP could be produced by a typical Part 15 AM transmitter and whip plus its "ground conductor" when mounted on an elevated structure.

//