We had this discussion in the past with Carl Blare as to what is a "stage" in electronics. The FCC part 15 rule states this.....Fundamental Rule (§15.219):(a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed 100 milliwatts.
The key word here is stage. The actual rule doesn't say amplifier stage. This leaves a loophole in the interpretation of what the final stage is....does it have to be an amplifier or not. In the case of the Talkinghouse my personal opinion is if the antenna tuner in the main unit is bypassed and a length of coax feeds a final RF stage, that stage being linked to the main unit even though separate and that stage does the final RF tuning, passively but still a stage, and the antenna attaches to that, it performs a function and therefore is a final RF stage. That is probably how it got certified as a lab also agreed that the final stage was the remote antenna tuner, electrically connected but not in the main unit itself. As Artisan has pointed out that Procaster tried and failed to get a similar set up approved in Canada.
Subject to interpretation. I think that in keeping with the definition of a stage in electronic circuitry the final stage can be the range extender itself.
For example a low pass filter is a "stage" as it performs a function but isn't an amplifier.
A detector in a radio circuit is a "stage" as it performs a function but is not an amplifier.
A rectifier converting AC to DC is a "stage" but is not an amplifier.
@NightAire, sometimes I think that it's better to ask forgiveness than permission. But I understand your reluctance to even potentially step out of bounds so to speak, in running a Part 15 transmitter.
I'm not sure, though, that you'll get a straight and consistent answer. When I first started out back in 2006, I contacted Industry Canada with a list of questions, but was told to go away. First, I knew more than anyone I talked to there (after several months of research) and second, they were complaint driven. The situation is likely similar for the FCC.
I'm not located in the U.S., but from reading of others' experiences, I believe there you have to be compliant. Certification isn't as much of an issue (devices have to be certified to market and sell them only). There have been plenty of operators that have run uncertified but compliant transmitters and antenna systems, and have been OK'ed by the FCC. There are even provisions in the rules for home built devices.
In Canada, all transmitters used have to be certified by ISED (formerly Industry Canada), and not only that, but for the use they are certified for. So there is a broadcasting certification (BETS-1), and a non broadcasting certification (RSS210) - both license exempt. But you can't broadcast using an RSS210 transmitter. We've talked about this at length here in the past.
The U.S. rules to me are a bit crazy. What's the point of certifying a device if you can still get into trouble using it? Plus, I'm not convinced that certification means all that much anyway. There are plenty of so-called certified devices, primarily on FM, that are not compliant as sold in the retail chain (the Whole House 3, the BVE AXS-FMT(D), and more). And then there are the suspect labs that issue FCC ID's for obviously illegal transmitters running multiple power levels up to 7 watts. The FCC is supposedly cracking down on the latter, but there are still plenty of the transmitters around, and you can easily purchase them on ebay and other such outlets.
If you're planning on using AM (and in the U.S., there's not really much choice, FM field strength levels are miniscule), you'd be fine no matter what you do as long as you are in compliance with the rules as generally accepted, i.e., 100mw input to the final (amplifier) stage, antenna and ground system truly meeting the 3 meter length (so a ground mounted installation), no interference to existing stations, etc. I'd go with a Rangemaster or a ProCaster - they're well known within the Part 15 and FCC world, certified as a bonus, give great sound and range and are basically bulletproof. The Talking House's reliability is dubious at best; I've owned multiples way back when because they kept on breaking, or never worked right. I've even owned the original Range Extender (which is how I know what was inside).
@artisan-radio I am starting to get the feeling they're annoyed I'm even asking about all this. Even the first response back was pretty snarky.
I want to do everything I can to avoid interference: I want to put the antenna and transmitter in the center of my back yard, away from power lines, buildings, or anything else that could radiate. I want to limit my bandwidth to 5 KHz (as much as it pains me) to avoid getting outside of my frequency. I spent many hours, day and night, and on the internet in multiple databases, to determine the frequency I picked truly was clear and clean. I'd like to have a local engineer come out with a scope and just make sure I'm not bleeding onto other frequencies, creating any harmonics, etc.
If I know they'll leave me alone (and I understand the FCC is losing a lot of money these days trying to chase down pirates), I'll happily do my thing on AM and not bother any licensed services.
In searching FCC notices, it looks like they're taking down A) FM pirates, B) stations interfering with licensed broadcasters, and C) AM broadcasters using 40 ft water towers as a "ground" and covering miles.
I plan to do none of those things.
Playing catch-up here...
It's all wordplay. ....
.. I think that's what the FCC intended, and what every other manufacturer of Part 15 transmitters accepts.
..... At the end of the day, it's really only the FCC inspector's opinion that matters. Hopefully, it never comes to that.
The FCC never intended Part 15 transmitters to be used like they are. They actually repeatedly specifically emphasized they never intended that part 15 AM have the capability it has, they tried to put the genie back in the bottle back in 1970-something when they decided to abolish the alternate rule (15.219), but it survived by the skin of its teeth. Point being "what the FCC intended" doesn't really have much bearing on the subject at hand. Intentions behind the rules are irrelevant, only the rules as written are relevant. That's the only reason this hobby exist.
I'm with you that the ground leads count. I was looking at an old test on Hobby Broadcaster and they GROUNDED the transmitters! That tells you how all of them operate IF grounded... but that's not legal operation (unless you chop off a bunch of antenna).
Not sure what you're saying there
I've read buried radials don't count. Fantastic! ...Until I got a response back from OETECH telling me they 100% absolutely DID count and if I put down 32, 15 ft radials that would be a wildly illegal operation.
Whoever from OETECH you talked to - uh, well, that's just false, buried radials do not play into the part 15 3 meter rule in anyway whatsoever. You can have as many buried radials as you want. -- By the way, who is OETECH??
Right now I'm waiting to hear back if it's illegal to operate a transmitter that's FCC "compliant" even if it's not FCC "certified." That's the way the rule reads but I'm hoping against hope they'll say that's not the case. I was looking REALLY hard at a UK company that makes a Spitfire and a Hurricane. They look fantastic but they are NOT certified... which I think makes me a pirate if I were to order and use it.
Yes, "compliant" and "certified" are interchangeable terms as far as the user or the FCC is concerned. "Certification" applies exclusively to the marketing.
The answer is Yes, it is 100% Legal to operate a transmitter that's FCC "compliant"
The Spitfire is FCC compliant, the Hurricane is not. (As for how they can sell them, I don't know, but it perfectly legal for you to purchase and operate them.
I'm also hoping they'll let me know if you can use a home made antenna (within guidelines) with a certified transmitter. ...
The answer is yes, but doing so would void the certification thus puts the responsibility on you to ensure it's compliance (which is the case regardless anyway). Yes it legal to construct your own antenna for the transmitter and voiding the certification to do so doesn't mean squat anyway - because it's always YOUR responsibility to insure your in compliance with the rules.
... As a result, I feel I have to dot ever "i" and cross every "t" and maybe spend $1,000 I don't have in an effort to cover a half-mile. Back to the topic at hand: I read somewhere else that "certified doesn't protect the broadcaster" and I have to wonder if anybody using the Talking House has ever been busted for just that thing. It doesn't sound legal to me, certified or not.
Again; Certified not only doesn't protect the broadcaster, it doesn't have any effect on him at all. Certification only allows marketing of pre-assembled transmitters, nothing else, that's it.
We had this discussion in the past with Carl Blare as to what is a "stage" in electronics. The FCC part 15 rule states this.....Fundamental Rule (§15.219):(a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed 100 milliwatts.
The key word here is stage. The actual rule doesn't say amplifier stage. This leaves a loophole in the interpretation of what the final stage is....does .....Subject to interpretation. I think that in keeping with the definition of a stage in electronic circuitry the final stage can be the range extender itself.
For example a low pass filter is a "stage" as it performs a function but isn't an amplifier.
A detector in a radio circuit is a "stage" as it performs a function but is not an amplifier.
A rectifier converting AC to DC is a "stage" but is not an amplifier.
To me it all made perfect sense to me when Carl always insisted the antenna itself was the final stage ( though you could never be sure if he was being sarcastic). But yeah, now after our previous discussions I agree that it more likely that it refers to the actual electronic circuitry.
@NightAire, sometimes I think that it's better to ask forgiveness than permission. But I understand your reluctance to even potentially step out of bounds so to speak, in running a Part 15 transmitter.I'm not sure, though, that you'll get a straight and consistent answer..
Agreed, set up your system in such a way that seems consistent with the rules and put it in operation and you'll probably never have a problem. if you discover your achieving miles of range, then you'll know for certain you have a potential problem, but chances are nothing will happen, not on AM anyway, but at least you'll know your not legal anymore!
@artisan-radio I am starting to get the feeling they're annoyed I'm even asking about all this. Even the first response back was pretty snarky.
I want to do everything I can to avoid interference: I want to put the antenna and transmitter in the center of my back yard, away from power lines, buildings, or anything else that could radiate. I want to limit my bandwidth to 5 KHz (as much as it pains me) to avoid getting outside of my frequency. I spent many hours, day and night, and on the internet in multiple databases, to determine ....
You need to relax and quit being so overly cautious. Theses expensive transmitters are still nothing more than a child's toy, that's why they don't need a licence. The FCC will most likely be oblivious your station even exist, nor care. AM citations used to be rare, now they've become completely non existent for about a decade now.
I understand your concerns too, and even appreciate them, but really I think your seriously overthinking it. Just set up your station and have fun. The very very worst thing that could ever happen is that the FCC sends you a notice that says to stop doing that - and it's pretty unlikely that will ever happen.
Not sure what you're saying there
Grounding the transmitters could benefit some transmitters more than others. Most of us will run a 3 meter antenna without a ground... so the test wasn't exactly "apples to apples." While their tests showed this transmitter performing better than that transmitter, if I hook it up here without a ground, my results could be different.
The Spitfire is FCC compliant, the Hurricane is not.
It's not? They're both the same internal guts (and that's straight from the guy who makes them), and they're both 100 mW into the final stage. Am I missing something? The Mosquito and Tornado are both way too powerful, of course...
who is OETECH??
OET stands for the FCC’s Office of Engineering and Technology. Their page on the FCC website (including their email address) is here: https://www.fcc.gov/engineering-technology
This is the email exchange we had:
Inquiry Details on 05/04/2026:
Inquiry:
I'm looking to set up a legal Part 15 AM station in my backyard, and I'm having a terrible time locking down whether or not buried radials count as part of the 3 meter antenna/ground, or not.
Some online argue it is only like putting a "mirror" under your antenna, to make sure all the radiation flows up and out. Others argue just as convincingly that every radial you bury is illegally extending your antenna further and further, and unless you want nothing above ground and only nine, one ft radials, you shouldn't use any at all.
Are radials a practical way to improve Part 15 signal coverage, or an illegal extension of the primary radiator?
Thanks so much in advance for your reply. I want to do this right.
FCC response on 05/11/2026
Hello,
Thank you for the inquiry. Under 47 CFR §15.219, the total length of all radiating elements, antenna, transmission line, and ground lead including any metal poles or ground radials, must not exceed 3 meters. Radials therefore count as part of the ground lead, not a loophole to improve efficiency. Their use can easily push the installation beyond the legal limit, increase emissions, and extend range beyond the roughly 400 feet expected for compliant Part 15 AM systems. In that case, they effectively become an illegal extension of the radiator.
While radials can improve transmitter efficiency from a technical standpoint, the Part 15 rules intentionally restrict such improvements to prevent harmful interference. Any installation showing significantly greater range is likely out of compliance, regardless of how the added efficiency was achieved.
Thank you
OET
The answer is Yes, it is 100% Legal to operate a transmitter that's FCC "compliant"
I feel like I'm being a killjoy, but check this out: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-15/subpart-A/section-15.1
Unless specifically exempted, the operation or marketing of an intentional or unintentional radiator that is not in compliance with the administrative and technical provisions in this part, including prior equipment authorization, as appropriate, is prohibited under section 302 of the Communications Act of 1934, as amended, and subpart I of part 2 of this chapter...
I'd be happy to plead ignorance on this, but it sure reads to me like you can't operate equipment that isn't authorized. I WANT to be wrong about this.
You need to relax and quit being so overly cautious.
Oh, trust me: if you need someone to overthink things, I'm your guy.
Perhaps I should apply the lyrics to the theme for Mystery Science Theater 3000 to my Part 15 adventure: "...then repeat to yourself 'it's just a show / I should really just relax'.." 😀
Thanks for your reply; I'm gonna take your advice.
.The Spitfire is FCC compliant, the Hurricane is not.
It's not? They're both the same internal guts (and that's straight from the guy who makes them), and they're both 100 mW into the final stage. Am I missing something? The Mosquito and Tornado are both way too powerful, of course...
Ah! Yeah you're right, I guess I was thinking about the Tornado
.who is OETECH??
OET stands for the FCC’s Office of Engineering and Technology. Their page on the FCC website (including their email address) is here: https://www.fcc.gov/engineering-technology
This is the email exchange we had:
Inquiry Details on 05/04/2026:
Inquiry:
I'm looking to set up a legal Part 15 AM station in my backyard, and I'm having a terrible time locking down whether or not buried radials count as part of the 3 meter antenna/ground, or not.Some online argue it is only like putting a "mirror" under your antenna, to make sure all the radiation flows up and out. Others argue just as convincingly that every radial you bury is illegally extending your antenna further and further, and unless you want nothing above ground and only nine, one ft radials, you shouldn't use any at all.
Are radials a practical way to improve Part 15 signal coverage, or an illegal extension of the primary radiator?
Thanks so much in advance for your reply. I want to do this right.
FCC response on 05/11/2026
Hello,
Thank you for the inquiry. Under 47 CFR §15.219, the total length of all radiating elements, antenna, transmission line, and ground lead including any metal poles or ground radials, must not exceed 3 meters. Radials therefore count as part of the ground lead, not a loophole to improve efficiency. Their use can easily push the installation beyond the legal limit, increase emissions, and extend range beyond the roughly 400 feet expected for compliant Part 15 AM systems. In that case, they effectively become an illegal extension of the radiator.
While radials can improve transmitter efficiency from a technical standpoint, the Part 15 rules intentionally restrict such improvements to prevent harmful interference. Any installation showing significantly greater range is likely out of compliance, regardless of how the added efficiency was achieved.
Thank you
OET
" Under 47 CFR §15.219, the total length of all radiating elements, antenna, transmission line, and ground lead including any metal poles or ground radials, must not exceed 3 meters. Radials therefore count as part of the ground lead,...
....from a technical standpoint, the Part 15 rules intentionally restrict such improvements.."
He contradicts himself in his response. He first clearly states the total length of all radiating elements must not exceed 3 meters, and then follows up falsely indicating that ground radials radiate and therefore are included as part of the 3 meters.
"...including any metal poles or ground radials"
It doesn't say that in the rules anywhere at all.
It's kind of like asking the city if you need to get a permit to change out your broken air conditioner unit. Of course you do, but you would have saved yourself a lot of hassle and expense to just did it without asking. -- What I mean is all your doing is asking for trouble when it's neither necessary nor beneficial.
The fact is from a technical standpoint, the Part 15 rules do not restrict ground radials, because ground radials do not radiate, thus not a radiating element, thus not part of the three meters. I can see that clear as day and I am not any kind of technician at all - but I can read, and there is nothing in the rules that even implies ground radials are not permitted. I don't know who that OET individual was but you did not receive an accurate response (Is that actually how your letter was signed? "OET"? An office worker maybe? It's just wrong.
.The answer is Yes, it is 100% Legal to operate a transmitter that's FCC "compliant"
I feel like I'm being a killjoy, but check this out: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-15/subpart-A/section-15.1
Unless specifically exempted, the operation or marketing of an intentional or unintentional radiator that is not in compliance with the administrative and technical provisions in this part, including prior equipment authorization, as appropriate, is prohibited under section 302 of the Communications Act of 1934, as amended, and subpart I of part 2 of this chapter...
I'd be happy to plead ignorance on this, but it sure reads to me like you can't operate equipment that isn't authorized. I WANT to be wrong about this.
Maybe you should read it again:
Unless specifically exempted, the operation.. of an intentional or unintentional radiator that is not in compliance with the administrative and technical provisions in this part,.. is prohibited under section 302..
It simply states you can not operate a non-compliant transmitter. That's very clear, everyone knows that. A compliant transmitter is just as "authorized" to operate as a certified transmitter is.
I just had a thought... I kind of wonder if that might have been an FCC OET Ai assistant that had replied to you.. It's getting harder to tell in recent years who's a real person with online communications.
It would explain the inaccurate response.
Now that's an interesting possibility!
I'm going to stop sweating a lot of this, try to do the right thing, and get my station going. If I can get 1/4 mile to 2 miles, and I'm not interfering with anybody, I'll be happy... and if the FCC complains, I'll make their required modifications to make it "legal," whatever they determine that to be.
Thanks for the encouragement! I'm excited to get started.
@nightaire Just a suggestion, if you want to get a better grasp of what the rules say - the online database your using is fine, it's great, it's always the most up to date - but unless your already familiar with the whole of them it makes it difficult to see the whole picture. Kind of like select verses from the bible to confirm or strengthen an agenda, easily taken out of context. You might find that just downloading the whole book and examining it as whole presents a clearer perspective: This one is 10 years old but close enough, I'm not sure what the most recent was, but the rules haven't changed since 1990 I don't think and here's the one I turned up (2010): https://www.govinfo.gov/content/pkg/CFR-2010-title47-vol1/pdf/CFR-2010-title47-vol1-part15.pdf
Now that's an interesting possibility!
I'm going to stop sweating a lot of this, try to do the right thing, and get my station going. If I can get 1/4 mile to 2 miles, and I'm not interfering with anybody, I'll be happy... and if the FCC complains, I'll make their required modifications to make it "legal," whatever they determine that to be.
Thanks for the encouragement! I'm excited to get started.
That's the spirit! You might just inspire me to get off my ass too! I've been talking a lot about getting my station back on the air but haven't actually done anything other than buy some more gear to "get ready"! - just haven't yet, it's coming though.
You'll most likely be able to get a 1/4 regardless of your surroundings, ground conductivity, local interference, etc. A mile or two radius potential is a reasonable hope as well, it's all dependent on your immediate surroundings and especially the ground conductivity of your region. Have you looked it up your area on the FCC map? https://www.fcc.gov/media/radio/m3-ground-conductivity-map
Just a technical aside. Radials installed perpendicular to your antenna and opposite of each other, regardless of whether they are elevated or not, do not radiate. That can give you an artificial ground for an elevated install. But whether they would be considered part of your antenna if they are elevated would be up to an FCC inspector, who has a lot of discretion.
If those elevated radials are not equal in length and opposite to each other (say, 4 radials, 90 degrees in separation, and all 3 meters in length), then they definitely will radiate. As will sloping radials. In fact, elevated, sloping radials have been used for years in amateur radio to improve signals, particularly on the lower bands (160 & 80 meters).
I agree that you should just do your best to comply with the regulations and just go ahead. If on the off chance you do get inspected, intent goes a long way with that inspector (they're people too).
Just wondering about the FCC response NightAire got from the FCC? It said this....Thank you for the inquiry. Under 47 CFR §15.219, the total length of all radiating elements, antenna, transmission line, and ground lead including any metal poles or ground radials, must not exceed 3 meters. Radials therefore count as part of the ground lead, not a loophole to improve efficiency. Their use can easily push the installation beyond the legal limit, increase emissions, and extend range beyond the roughly 400 feet expected for compliant Part 15 AM systems. In that case, they effectively become an illegal extension of the radiator.
Somehow you have to question that. Yes the radials will radiate but they are underground and being so do not radiate into space. They would just make signal propagation from the antenna better. Also no distance is specified in their rules. Distance also depends on the receiver. The wording is antenna and ground LEAD, which seems to not include what is underground. This keeps the lawyers busy! Just like the nonbroadcasting/broadcasting in Canada.
I was using a Procaster from the basement of a house with no ground connected to the Procaster itself and a wire instead of the stock antenna clipped to the antenna lug on the cabinet and used a 3 prong, earth grounded power supply and was getting more than 400 ft. It could be heard 1/2 a km(just over 1600ft) around me in the daytime although some of that was fringe and heard only in a car.
The electrical ground in a typical home is a copper and steel stake 8 to 10 feet in the ground. Does that mean you can't power it from a wall socket because you are using the building electrical ground/wiring, and that will make it work better?
Radials of equal length, 180 degrees apart, and perpendicular to the antenna do not radiate, whether they're in free space, on the ground or buried. The currents running through them cancel out. They basically make the antenna radiate more efficiently.
So, for a 3 meter antenna, instead of 0.5% efficiency or less, it may go up to 1% or so. If the FCC is looking at the elements of an antenna system that radiate, radials that meet those above conditions do not enter into the equation.
@richpowers In my mind you are correct about everything in your post about what NightAire got from the FCC. Go by the actual wording of the written rules....what is specified in writing.
@ Nightaire
When you try to contact them(FCC and ISED/CRTC Canada), you get things like this that they are trying to tell you that the written rule doesn't. "Oh you can't do that and that"....I, (Artisan and I) have had this from ISED and the CRTC the same as the reply from the FCC. In fact when I once contacted by phone and spoke to someone at ISED to ask about something the person said about the AM or FM bands....."oh you can't go there, that is a broadcast band and needs a license". I said what about BETS-1 and RSS-210? ....then I was asked, "what do you want to do this for"? At that point you just hang up and don't pursue it farther! As soon as you are asked what do you want to do this for.
I emailed the CRTC a while back about BETS-1 and broadcasting(Canada) to a local area and asked a question and was told "oh no, you can't be a little hobby station", "You can't play music". But the written rule clearly in it's wording does not say that that's not allowed. It actually implies it is allowed as long as some rules are met.
When speaking to Decade, maker of the MS-100 in Canada certified as broadcast equipment he has had this from ISED and the CRTC people there all the time. It is a pain to deal with them as they don't know what is what themselves. Decade told me you can broadcast anything as long as it's not political, racist, or hateful, and keep it clean. And that is what the rule states.
It is best not to contact them at all ....the FCC, ISED, or the CRTC.
@richpowers Looks like I'm "15" on the FCC's map, although I'm not sure exactly what that means...
@artisan-radio Should the radials be 3 meters as well, or if I can go farther is it better? (I can't go MUCH further, maybe 15 ft.) Also, I'd also heard someone recommend up to 32, not just 4... is there a level of diminishing returns?
@mark It's insane, to me, that you can't get an honest answer from the organization that's supposedly working FOR you (using your tax dollars, anyway). Time for me to stop asking questions...
Quoting Emo Philips: "you guys are really cheering me up." 🙂