New Ruling on Definition of Ground

I agree, too much pounding in on the subject of grounds, it's become overwrought, if that's the right word, like Part 15's version of talk show topics, "the death penalty", "Nazis and Hitler", and in some ways racial issues and taxes. You feel beat, spent after listening, and yet nothing has been accomplished or better understood.

I think the topic should be buried. That is, except for in the practical sense of how to make a better gnd. I'd like to see more threads with real information, like the real life transmitter tests on the Whole House and Decade transmitters that have been done.

I'd like to see more on carrier curent, where it's like you're transmitting into several levels of ground, earth and power line grounds. If not, you guys will be grounded for a month.

Absolutely, Nate Crime, we really need to revive interest in carrier current, the homeless older relative of modern Part 15 radio. It's waiting in the rules for us to pick it up and get it going again.

There are dangers associated with carrier current, good reason to steer clear of it for safety reasons. But if we take a smart pill maybe we can solve the danger problem.

Obviously the risk to life starts whenever opening the electric panel to attach wiring to the 220V Hots. A shaky hand or a sudden lurch due to a lunging spider could put you in the obituary.

Transmitter manufacturers are shy about causing death, which may explain why none of them goes near carrier current in their catalog of offerings.

Here's my plan. Once you have your coupler and CC transmitter, make a phone call. Bring in a qualified electrician to install a 3-prong 220V socket alongside your power panel.

A transmitter manufacturer enters the scene with a newly designed SAFE coupler outfitted with a male 3-prong 220V power plug. Your easy and risk free task is now simplified as you connect the coupler to the new socket and the transmitter to the coupler. Your life expectancy is neatly preserved and you are ready to broadcast using carrier current.

Of course there's that alternate CC method known as "neutral injection" so we'll need a different approach for wiring, but it's a safer method, so we can deal with it now that we're smarter.

Just yesterday on the nearby thread "Hello, Also Help?" the member WaxyMouthfeel said "carrier current terrifies me." This got me to thinking and I haven't stopped. We can do this.

The problem is the FCC rules for Part 15 do not define ground.  They only give a specification for a ground lead. Clearly the goal is to limit the length of anything that will radiate. So the three meter total for antenna and ground lead is given.

So, what if you have a three meter antenna on your transmitter and it's mounted 50 feet in the air on a wooden pole.  To the ground connection of the transmitter you attach a 40 foot wire that hangs down from the transmitter and is connected to nothing.  This is not a ground lead.  It is not connected to ground. It's simply a piece of wire. As defined in the rule this is legal.  It's clearly not a ground lead. It's probably best defined as a counterpoise, but that is not mentioned in the rule.  But you can be darn sure that a visiting agent would define this as a ground lead and cite you, because it is radiating.  What is the legal definition differentiating the counterpoise from half of a dipole?

I also note that the rule does not specify "RF ground".  So that leaves another huge area open to interpretation. 

Clearly anything connected to the transmitter ground that is a continuous path to the Earth will count as ground lead length.  If your little 4 inch ground lead connects to a 30 foot flagpole planted in the Earth that's a 30 foot 4 inch ground lead.  But again, apparently open to interpretation. 

Curious.  Speaking of NOUOs, I've noticed plenty of posts over the past couple years about people who have received them, some rather old and somewhat legendary.  Do we have any documentation on anyone who has ever appealed one? You have the right to respond and appeal. I imagine someone who knew they were operating illegally wouldn't appeal, but someone running a certified transmitter installed by the book, I would think, could certainly appeal. But I haven't seen any documentation for this. Stories on occasion.  But there seem to be plenty of fiiles online for NUOUs but nothing on appeals. 

We could ask for better definitions in the rules, but we may not like what we get. 

TIB

Interesting post, TIB.

The problem is the FCC rules for Part 15 do not define ground. ...

The nature/definition of an electrical ground is provided by physics.  Here is a clip about electrical grounds from one resource ( http://whatis.techtarget.com/definition/ground).  I used a bold font to emphasise an important fact.

• Electrical grounding is important because it provides a reference voltage level (called zero potential or ground potential) against which all other voltages in a system are established and measured. ... When a point is connected to a good ground, that point tends to stay at a constant voltage, regardless of what happens elsewhere in the circuit or system.  The earth, which forms the ultimate ground, has the ability to absorb or dissipate an unlimited amount of electrical charge.

A vertical conductor connected to the earth is approximately at zero (earth) potential for radio frequencies exactly, and only at its base.  Above that elevation, r-f current and voltage can exist, and where it does that conductor will radiate EM waves.

This is the reason that the tops of grounded metal flagpoles, towers, billboard frames etc do not supply an r-f ground to a short lead connecting them to the r-f ground terminals of elevated transmitters.

... So, what if you have a three meter antenna on your transmitter and it's mounted 50 feet in the air on a wooden pole.  To the ground connection of the transmitter you attach a 40 foot wire that hangs down from the transmitter and is connected to nothing.  This is not a ground lead.  It is not connected to ground. It's simply a piece of wire. As defined in the rule this is legal. ...

It makes no difference to system radiation if the 40 foot wire is connected to the antenna output connector of the transmtter and the ~ 3m conductor described as "the antenna" is connected to the r-f ground terminal of the transmitter.  In neither configuration does either wire have connection to ground as defined by physics.  Yet probably most would agree that a 40-ft wire connected to the antenna output of the transmitter would be non-compliant with FCC § 15.219(b).

What is the legal definition differentiating the counterpoise from half of a dipole?

Normally a counterpoise produces no useful far-field radiation.  That certainly is not the case for this 40-ft wire.

The 40-ft wire in this discussion is not a counterpoise -- it is one side of an off-center-fed, linear dipole.  A dipole is a balanced antenna, and does not need/use a connection to an r-f ground to radiate efficiently.

A counterpoise more commonly is a configuration such as decribed in this link:

https://en.wikipedia.org/wiki/Counterpoise_%28ground_system%29

Tim makes a vivid point by saying: "We could ask for better definitions in the rules, but we may not like what we get."

Because technical language takes on the dimensions of physical, electrical and magnetic space, it is virtually impossible to condense and simplify with anything but a sketchy outline of which 15.219 is an excellent example. It is probably a masterpiece in its ability to reduce instructions to a street level.

Think of "ground lead" as kind of an arrow pointing toward a mysterious place called "ground" which literally "goes without saying" in 15.219.

By contrast the FM rule 15.239 is entirely different, despite its brevity, by fobbing the responsility on the user to achieve measurements that the majority will have no means of accomplishing. 15.239 stands as an example of a definition "we do not like to get," since there's nothing we can do with it.

I hold to the position I make in the opening post and consider it highly logical. At the same time Rich's post just prior to this one seems true on its face in terms of scientific principles of electronics.

The world in itself has gray area and is not black and white.

Perhaps we could say that Rich is a black and white man while I'm a gray area guy.

All radio seems to come from a technical or dangerous past, things done in large ways, tall towers, high power, having the beware of lightning, and one had to be a real electro-magnetic engineer to work with it. Now we have bite size FM transmitters for $6 from dollar stores, and there have always been toy AM mics around.

We might be able to hobby size carrier current as a start, it shouldn't cause any more terror than a wall outlet itself, and plugging a phone charger in, somethng you do every day.

A transmitter could be made to send the radio signal back down the same cord that powers it, like old intercoms and early cordless phones did, no exposed voltages. Better units could let you switch between neutral and hot, and have some kind of tuner in them, like the Talking House.

I do see that current carrier current equipment is professional, needing wall space for a rack to hold it, and wiring to the 220 volt lines. Maybe that could be the more advanced level of carrier current.

I'd thought that a ground lead would have to be leading to something, every use of lead seems to lead to something to complete a circuit, a lead-in for an antenna, test leads, and the lead for walking a pet connects pet to owner.

Tib, I always read low power radio news, but haven't seen anything about an appeal happening after someone is cited on AM. I don't collect the stories, but I read them, and can't remember even talk of an appeal.

The operators just seem to fade away from the press, and I've seen a few angry responses from a station, like one in Ohio a few years ago. It could be anger, embarrassment, intimidation, and they think they're done, and so just move on to another hobby, that's the impression I get.

One of the early AMs I heard about, several years ago, but the info was years old already, was a guy who had a bill board on the West coast US, and he put an AM transmitter on top of it. The range was several miles and someone complained to the Commission, who didn't find anything wrong. The complainer was really steamed and tried to get it inspected again. I don't know what the problem was, but it passed mustard every time.

I always thought if you set out to raise your transmitter on some wood pole with a wire to a ground stake, it might not be as kosher as putting it high on a billboard, building, hill or something else that's pre-existing. Then again, all tall structures connected to your home and electrical grid should be well grounded for lightning protection.

Almost everyone who posts about Part 15 talks in nickles and dimes about hoping to afford the next $20 item, so I don't see our class of citizen having the financial means to appeal or challenge a case, even when we feel right about what we have done.

There are probably no pro bono attorneys for hobby radio cases, so the authorities can pretty well rule the roost.

Anger is not only the last resort, it may be the only resort, and it usually fades out into the bad memory zone. It's hard to be polite and say, "Thanks for screwing me."

However, reality check, most of the violations that get talked about happened to somebody else.

Nate Crime posted, ... Tib, I always read low power radio news, but haven't seen anything about an appeal happening after someone is cited on AM. ...

An Oregon station allegedly using an FCC-certified Part 15 AM transmitter + ~3m whip, with the tx chassis "grounded" to the top of a ~40-ft tower was cited by the FCC for violation of Part 15.

All of the following is as I remember/saved from the posts and OEM websites of those days.

The owner/operator of that system claimed to be following the installation suggestions and drawings provided by the manufacturer of that transmitter, before/at the time it was installed.

At least informally, that operator appealed this FCC citation via a member of the U.S. Congress.

Later on that transmit system was modified using a filter designed and supplied by the manufacturer of that transmitter.  The FCC re-measured that system after installation of that filter, and found that it was non-compliant with Part 15, still.

After this, the operator of that system closed it down without further action/appeal.

Valid corrections to this narrative will be gratefully received.

Short of contacting the operater of that downfallen station, we wonder - why couldn't he simply re-locate his transmitters to the ground?

If he had the means to place transmitters up high on city structures, and sought to filter the illegal ground-leads, think about it... had the filters functioned as hoped he'd have had the equivalant of a ground mounted transmitter, I guess.

It's a story that gets recalled forever, so maybe we need a historian to dig into it and gather all the facts, including the circumstances leading up to the inspection and violation.

... If he had the means to place transmitters up high on city structures, and sought to filter the illegal ground-leads, think about it... had the filters functioned as hoped he'd have had the equivalant of a ground mounted transmitter, I guess. ...

1) IIRC, the first Part 15 AM system of this particular operator was installed at the top of a ~40-ft tower purchased and installed by that operator -- IOW, not on any city structure.  Still, it was cited by the FCC.

2) Even if a filter could equate the performance of an elevated system to one mounted at/near the earth in full compliance with FCC §15.219, would any rational operator choose the additional expense of installing/optimizing such an elevated & filtered system when it would provide no performance benefit with respect to a compliant Part 15 system installed at/near the surface of the earth?

Rich just said these words: "Even if a filter could equate the performance of an elevated system to one mounted at/near the earth in full compliance with FCC §15.219, would any rational operator choose the additional expense of installing/optimizing such an elevated & filtered system when it would provide no performance benefit with respect to a compliant Part 15 system installed at/near the earth?"

Earlier it was noted that Ken Cartwright, KENC, the subject of discussion, actually went to the extent of trying a filter provided by the manufacturer of the certified transmitter.

Why would Mr. Cartwright fuss with such an attempt to comply if the only result, if succesful, would be to diminish his range? Yet, he hosted the experimental filter, unfortunately found insufficient by an FCC followup.

We have a contradiction.

People can do whatever they want. Someone can put a certified part 15.219 transmitter with a 102” CB whip antenna at the top of a 132ft pole and use a 16” ground lead to tie it to the pole and operate on 1640kHz. The result is pretty close to a quarter wave of metal that can radiate. The range would be awesome. Nothing stopped the person from doing it, but someone will take notice. Then when an inspection happens, it all comes down to how the inspector views putting a part 15 transmitter on a pole that happens to be close to a quarter wave for the chosen frequency. Part 15.219 does not stop anyone from mounting their transmitter however they want. But there are consequences of not following the rules, so if an inspector came a NOUO could probably be issued. Part 15.219 allows for a very specific type of non-licensed RF transmission, and if an install is not covered by 15.219 (or 15.209), there is a violation of needing a license to use frequencies in the AM broadcast band.

So just because someone on the internet says “you must do it this way or it is illegal” nothing stops someone from doing it some other way.

Personally I would never do an elevated install because I don’t feel like seeing how the FCC agents near me would measure 3m. But nothing anyone says on this forum or HB physically stops me from installing a transmitter in some potentially non-compliant way.

If you remember in the CB days the height of the antenna was 60 feet. But if you were to install the antenna on a roof it was 20 feet and that was it. Using this and applying the rules to 15:219 we are allowed our antennas to be 3 meters from the ground to the top of the antenna. This translates to 10 feet. What this means is that 5 feet is allowed for the hot element and 5 feet is for the ground. Yes you could have had a balanced AM antenna at this point. But many folks use a 8 or 9 foot antenna leaving only 1 foot to 2 feet for the ground lead. Its my interperation that in all intent and purposes that the FCC meant to have the transmitter on the ground level. With that in mind you could have it on a 35 foot hill so long as its on the ground level with say 3 foot PVC pipe. If you look at the Transmitter challenge on Hobby Broadcaster (I was not banned by the way) you'd see most are not high off the ground. I saw the picture of Bill and his broadcast engineers in the pic along with the ATU installed for the iAM transmitter. This like it or not is the typical install. When in the house you can have a 6 Ft antenna as long as you only allow a 3 foot ground lead. In this case the power cord from my power bar the power supply counts as a ground. The transmitter has to be grounded for safety. Since the construction of my first floor room is not smack dab on the ground this would be legal. But if I put up a 20 foot plastic PVC pipe and put the outdoor unit up even without ground this is an elevated install. This is something the FCC did not intend as far as my interpretation of the rules. We try and get around and hope they will accept our install but if you look at the rules at face value there is nothing about putting our ATU or transmitter 20, 30, 40 feet on a pvc pole off the ground. We do this in hopes of greater range. I've seen pics of installs on the top of a fence again possibly illegal if its above 10 foot above ground. Some inspectors may overlook this and we hope they only look at the antenna size and ground wire. I'm thinking this is where some of the NOUO's come from. At least this is something we need to look at in further detail just as we had to look at the FM initiative a while back. If KENC was not accepted and found in violation after the filter the ground may not have been the issue. The elevated install was the issue and the inspector tried to use the closets thing that was written in the book to violate the operator. This is something to study.