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Author Topic: Type acceptance of radios (not trolling!)  (Read 9304 times)

Posts: 5

« on: February 11, 2010, 06:50:16 PM »

I don't mean this to sound like a trolling post, unless all trolls say that up front...

I was reading some posts this evening in the VHF forum, and it kind of highlighted some questions I, and perhaps others, have.  I'm particularly focusing on type acceptance/classification of radio gear.  A couple of cases in point:

The flood of Chinese HT's on ebay (Puxing, Weirwei, etc).  I understand there can be issues with them being as wide frequency as they are, though some posts state that if you don't program frequencies out of band or transmit out of band you're okay.  A large segment of the folks against these radios mention how they are not type accepted by the FCC to operate on the amateur bands.

This brings up my first question:  Keep in mind I'm new at this, having only had my license a few months, but my main reason for getting my license was the experimentation side of radio.  Wouldn't I be able to build a 2 meter radio and use it?  It would have no formal type classification, other than being built with good engineering practice.  Is one expected to take detailed measurements of a home-brew radio to verify it's deviation, modulation, frequency stability and such?  Do the Chinese radios get bashed because they're a commercial product and thus expected to be certified, or are they built to specs that insure they will cause interference with adjacent users?

While I'm on a roll, another question came to mind while reading the same forum.  One member stated that using commercial HT's on GMRS frequencies was so much better than the typical bubble-pack radios sold for that purpose.  If I recall, it was recommended to pick up a used Motorola HT1000 and program it for GMRS (better audio, more rugged radio, etc).  How does one know if a certain radio is legal for a certain service?  I have a Motorola HT1250 that is in the GMRS bandsplit, can it be programmed to work there legally?  Does it just need to be accepted under Part 95?  How do you know without contacting the FCC every time you have a question about a radio?

If you've read this far, thanks.  If you have some answers to my questions, thanks even more!


Posts: 4710

« Reply #1 on: February 12, 2010, 02:29:25 AM »

KB3TEW: "Wouldn't I be able to build a 2 meter radio and use it? It would have no formal type classification, other than being built with good engineering practice."

That's correct. And it would be perfectly legal.

KB3TEW: "Is one expected to take detailed measurements of a home-brew radio to verify it's deviation, modulation, frequency stability and such?"


KB3TEW: "Do the Chinese radios get bashed because they're a commercial product and thus expected to be certified, or are they built to specs that insure they will cause interference with adjacent users?"

I don't know.

What matters is that there's a BIG difference between homebrewing a rig for your own use, and manufacturing  them for sale to others. Sets manufactured for sale have to be certified as meeting FCC regulations.

The certification regulations for other radio services are more stringent than the amateur ones, because the users in those services usually aren't formally licensed operators and cannot be expected to have much technical know-how.

73 de Jim, N2EY

Posts: 805

« Reply #2 on: February 12, 2010, 08:03:45 AM »

If you look at it from a regulatory point of view, you can't really expect operators in services that don't require any technical knowledge at all to know if their radios are compliant with the emission rules. They depend on their hired and licensed technicians and can't build or modify their own transmitters. And the services that matter most are channelized and often coordinated, so noncompliance can cause a lot of problems. So it's appropriate to have some review and certification of transmitters and restrictions on who can work on transmitters. Amateur licensees are at least expected to know the emission rules and at least know how to insure that they comply. I'll grant you that a lot don't pay much attention to it, and for the most part, they're using factory gear and are generally okay. But along with the privilege to build and modify comes the responsibility to keep it operating in compliance.

A lot of the Chinese stuff are exactly the same radios offered as name brand amateur radios, just in a different case and a diode added or clipped in the right spot to limit the transmit frequency range. Radios intended for the amateur service do not require type acceptance, with the exception of HF amps and HF amp kits. It gets a little trick sometimes. The FCC generally takes the practical view that, while many acceptance-exempt amateur radios can quite easily be used in modes reserved for other services, they draw the line when a 10-meter "amateur" radio is loaded with built in features designed strictly for CB operators. A 10-meter transceiver that has nothing inherently untoward as an amateur radio can get by, even though they nearly all go into CB service. You can't really prohibit a company from making a 10-meter amateur transceiver.

So yes, you really are expected to take measurements of a home-brew radio or whatever it takes to verify it's deviation, modulation, frequency stability and such, if that's what it takes to keep it compliant, but you don't have to report it or demonstrate it, except by operating it within the emission rules.

I think this is the FCC database where you can search for equipment authorizations:

Posts: 165

« Reply #3 on: February 12, 2010, 10:18:05 AM »

This isn't always the case in other countries, however. At one time, in Belgium, I'm told you had to take the circuit  diagram of a home brew tx to the licencing authorities, and in Singapore, you had to have 'type approval' even for a second hand piece of kit. This was, apparently, just a matter of taking it along to have the serial number registered and paying the appropriate fee.....

Commercially available amateur equipment in Europe has to meet various standards, althhough as a manufacturer, you can self certify. Fortunately, we have managed through the IARU to have specific exemptions in European law both for home brew amateur radio equipment and amateur radio kits.

Posts: 8911


« Reply #4 on: February 12, 2010, 05:15:38 PM »

KB3TEW: "Is one expected to take detailed measurements of a home-brew radio to verify it's deviation, modulation, frequency stability and such?"


I wouldn't say "no." to that.  I would say "sort of, but if you don't cause any trouble with it you probably don't have to."

But along with the privilege to build and modify comes the responsibility to keep it operating in compliance.

That's right.  

Now, a lot of homebrewing of whole radios involves exactly duplicating a known design.  Then you have some expectation that it will work like the guy who designed it intended.  If you can trust that design (like there are some measurements that someone did) that's probably pretty much OK.

But if you designed your own, or built an never-tested design, and you were out of compliance, you're responsible for that.

You are *not allowed to use* things that are out of spec for various emissions issues.  

Now, I think a lot of hams might agree that we don't expect homebrewers to be super stringent in testing.  This is my opinion, with a couple scenarios.

1)Operator one builds a 20m QRP SSB rig of her own design.  It puts out 5W and splatters a little because the mosfet final amp uses an inexpensive device with bad IMD specs.  Maybe the output low pass filter is not quite up to snuff and the third harmonic is -38dBc instead of -43dBc.  She uses this low power rig to a low dipole when she's camping.    

2)Operator two builds a contest station.  He puts a big antenna on a tall tower.  To save money, he **purchases** an untested, illegal to sell in the U.S. 1500W mosfet HF amplifier that uses inexpensive devices with bad IMD specs, and has a poor low pass filter so it's putting out more 3rd harmonic than it should too.

In my opinion, the QRM caused by op #2 is severe, selfish and inexcusable.  Furthermore, the out of band emissions are likely to get him in trouble.  The QRM caused by op #1, in my opinion, is just part of ham radio experimentation, and I can live with getting splattered on by a homebrewer for the sake of some learning and doing.  Plus, she's probably not going to get in trouble because the interference potential of a small QRP rig to a portable dipole is quite low.  

But I can't live with getting splattered on someone who just does it to save MONEY, and I hope they get nailed for QRMing someone out of band with their bad radio.

Now, does some cheap HT actually cause any trouble?  Probably not, especially if it's like JEO says and it's really the same circuit as a brand name certified rig sold wholesale without testing.  But if it does cause trouble, in my opinion, you do a much worse thing by operating a poor rig that causes trouble if you're just trying to save money, rather than if you built something that's an actual experiment that doesn't work very well.

The Chinese HT's are probably fine all in all.  I think most of the bashing probably comes from people who are deeply worried about a flood of poorly designed RF emitting equipment ruining the ham bands.

We're already drowning in a sea of noise from poorly designed consumer equipment that probably doesn't always meet FCC specs for UNintentional emissions.  And there's something of a threat from horrid cheap solid state amplifiers that are really intended for CB/freeband use that people bring along with them when they get their ham ticket and use on the bands.

I think the cheap HT's are something different than that, but the bashing and backlash comes in because it's critical to follow spectral regulations, both in radio gear and in other types of electronics, to keep the ham bands clean and useable.  Those regulations are there for a reason, and it's not just to extract money from manufacturers of electronics, even if some people think that's why it's done.  If you buy a cheap commercial rig that didn't get approved by the FCC, and it messes up someone else's ham radio experience, that's a big problem.

'Course there are some commercial rigs that DID get approved that mess up others' ham radio experience too, so again, you need to look at what the interference potential is and act accordingly.  




Monkey/silicon cyborg, beeping at rocks since 1995.

Posts: 71

« Reply #5 on: February 13, 2010, 10:40:24 AM »

If it is a transmitter or amp made to be sold to hams, it must be type approved for the ham bands. A ham can build whatever you like, but if you cause interference to another service, or excessive splatter in band, you can be held responsible. If the HT is sold as a ham radio, and comes set up to run on the ham bands, It needs to be type approved for that service. If it is type approved for another service, and can be modified for the ham bands, it need not be type approved for the ham bands. It does need to be type approved for something.

You can also take a transmitter type approved for another service and mod it for use on the ham bands, but not the other way around. Broadcast transmitters are type approved. A few hams have taken older low power AM broadcast transmitters and retuned them up to 160 meters. You do need to limit the audio band with from the original 10,000 + Hz down to about 3,000 / 3,500 Hz. They still sound sweet.

Posts: 5

« Reply #6 on: February 13, 2010, 05:19:15 PM »

Thanks for the thoughtful and explanatory replies.  I appreciate it, as some threads here and elsewhere dealing with the Chinese HT's have become a bit nasty...

So I guess I'm hearing that you are responsible for homebrewed equipment, and are expected to employ good engineering practice.  If it's generating noise or interference, you need to take care of it.  It's a different thing when you're offering a mass produced item for sale.  In that case, one has to get the item certified essentially to prove good engineering practice went into the design, because if it didn't it will have a much more widespread effect than one person's homebrewed rig.

As to the second part of my original question, what about using commercial gear on other services.  What I'm reading in one post states that using commercial gear on amateur bands is fine, and I had kind of figured that (though I didn't know for sure).  How about using commercial gear on other services such as MURS or GMRS?  My example was my HT1250 whose bandsplit includes the FRS/GMRS frequencies.  If one limits the power and obtains a GMRS license, can that equipment be used in the band?  How about an older VHF HT that might include the MURS band?

This is really more for my own education, I have several old FRS radios, and wouldn't bother using the HT1250 unless I knew I could and got a GMRS license.  Really just trying to understand how and when one can use equipment designed for one service in another.

Thanks again for all the info, please feel free to offer up any other thoughts on the subject.

73 - brian

Posts: 14491

« Reply #7 on: February 13, 2010, 06:38:15 PM »

First off, FCC "Type Acceptance" no longer exists. It has been replaced with "Certification". Except for external power amplifiers there is no "Certification" requirement for amateur radio equipment. With that exception, equipment does not have to be "Certified" for operation on the amateur radio bands.

Now there are Part 15 (not amateur radio Part 97) rules that require "Certification" of certain classifications of equipment such as scanning receivers, receivers with oscillators operating above 30MHz, and receivers containing digital computer equipment. This applies to making sure it meets specs for unintentional radiators and for scanning receivers to ensure that cell phone frequencies are blocked. Many of these rules can apply to some types of amateur radio equipment being sold commercially but it IS NOT "Certification for operation on the ham bands".

There are certain Part 97 technical requirements for amateur transmitters that we all are required to meet, whether home built or commercial, but it doesn't require the "Certification" process.

Bob  AA4PB
Garrisonville, VA

Posts: 2080

« Reply #8 on: February 22, 2010, 02:04:57 PM »

You are good to go with your HT-1250 on GMRS and MURS frequencies.  That's not a problem.  Surplus commercial FM gear has been in use on the GMRS band for years.  Obviously, you cannot use commercial FM gear on FRS (Family Radio Service) because of several limitiations, for example: power output and "non-removal antenna" requirements in FRS.


Terry, WØFM

Posts: 62

« Reply #9 on: February 24, 2010, 03:15:49 PM »

I'm going to run with the word "type accepted" because it's still the wording that I see used on recent equipment along with "Equipment Authorization". If it's changed to Certification, so be it.

Either way, the FCC's OET is responsible for assigning the type acceptance after the radio is evaluated and submitted to Laurel Labs at one time. Don't know if that's the process now.

Each radio is submitted for type acceptance under a specific service. If you look at a commercial UHF transceiver, you'll probably see several numbers like 21,22,90,95 etc. GRMRS is part 95. You need to look at this carefully. Just because it's a commercial UHF radio, it doesn't necessarly mean that the manufactuer filed for type acceptance under part 95. Some radios do not carry part 95 TA ID. I used to see this quite a bit in the 80's when I'd check a manual and didn't see 95 listed and have to tell a real PO'd GMRS owner. If you're in doubt, your radio has a type acceptance number that you can run at the FCC's OET page and view the approval,filings,communiations,and services that the unit is type accepted under. Many radios nowadays only list the TA on the ID tag and the rest is in the manual. It's important to note that a TA in other services not only is a technical requirement, but often has other components to insure turnkey operation by technically inexperinced personel,emergency hot button operation, enviornmental protection, and minimum conditions for operations such as voltage range that could be critical in an emergency and other features specific to a radio service.

Regarding the use of the Chinese radios. I think it's important to understand that there is a difference in offering for "sale or lease" and operation/use of a radio in the amateur service. You can build,modify, or use ANY radio from any source or service on the amateur bands as long as you comply with the minimum technical standards regarding interference and spectral purity which are often more stringent for other services. The standard for a manufactuer,importer,or reseller however is different. In order to commercially sell or lease a radio for the amateur service, the radio has to have met the technical requirements of part 15 and any other imposed requirements such as linear amplifier band coverage (didn't that change?), cellular blockout,etc. before a type acceptance ID is issued prior to sale and distribution in the states. That is all an amateur TA ID authorizes.

Let say you went to a hamfest and bought one of these chinese radios or a CB radio banned for sale in the states from a tailgate sale or were given one. There is nothing in the law that I'm aware of that prevents you from using the radios ON US AMATEUR FREQUENCIES as a licensed amateur. I emphasize that point. Using that funky RANGEROO import CB radio that either covers the 24 or 28-29mc bands, has FM and other wierd bells and whistles is perfectly legal on the ham bands. It is not legal to use on CB nor can you legally sell this radio, but you can legally own it as an amateur providing it meets the minimum technical standards for amateur radio. Ditto the Chinese import. Just because an amateur radio can operate out of band or the use of radio from another service such as marine or land mobile can be tuned or programmed to operate within the amateur bands is perfectly legal providing you have an amateur license.

Posts: 365

« Reply #10 on: February 24, 2010, 05:38:30 PM »

What has puzzled and surprised me is that no one has embarked upon the process of taking some of  these Chinese built radios through FCC acceptance process yet. I'm sure they would need some design changes to gain any FCC acceptance, but I doubt that would be a big challenge. It would seem to me that a enterprising upstart marketing centric company could pursue that path and make some decent money doing so. They could surely sell them for a price that undercuts the IKY's substantially, and having taken those radios through an approval process will remove the fears of potential customers of their appropriateness for us in the US on the ham bands.

This basic process is how Yaesu and Kenwood got their toeholds into the US ham market in the late 60's and early 70's. Two examples that I can think of are Yaesu via Tempo, and Kenwood via Lafayette and Allied. And I'm sure there are others. I'm just surprised that this hasn't happened yet with these 2M and 70cm radios. After all the Chinese companies have already effectively captured the SWL portable RX market already using a similar tactic.
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