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Question about DCC and FCC

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  • Member since
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  • From: Reading, PA
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Posted by rrinker on Wednesday, February 26, 2014 7:50 PM

 Anything that has a spark gap, or spark potential, like motor brushes on the commutator, has the potential to interfere with pretty much the entire frequency spectrum. To avoid TV iunterference they need to supress any harmonics for the typical UHF and VHF frequency ranges, which are int he megahertz ranges. What bachmann puts in also seems to interfere with 20-40KHz as well, which is the PWM frequency range of most "silent drive" decoders - which may partly explain why the cheap motro only decoders they used are not silent drive, and why the bachmann locos get greatly improved performance by cutting the capacitors out of the circuit, both for silent running DCC decoders and PWN based DC power options.

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

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Posted by cacole on Wednesday, February 26, 2014 7:06 PM

I believe those Bachmann LC filters are to prevent interference with the European PAL TV sets.

I don't know about the rest of Europe, but all TV reception was off the airwaves in Germany and model locomotives may have interfered with reception.

 

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Posted by richg1998 on Wednesday, February 26, 2014 12:50 PM

A little off topic but Bachmann puts LC filters in most their locos, here and abroad to satisfy the other side of the Pond requirements. Don't remember the frequency the LC filters are needed for.

 

Rich

 

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Posted by gigasaurus on Tuesday, February 25, 2014 11:06 PM
Wow. That search app is great. Thanks for finding that.
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Posted by rrinker on Tuesday, February 25, 2014 6:36 PM

 Go here and you can search by manufacturer: https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm

I found Digitrax, they list the MS100, DT100R, the UR91, the new 900MHz radio module, adn the new 2.4GHz radio module.

Tryinve NCE, it returned an awful lot of entries to sift through before I get to NCE the DCC company, and the site, like most things created by the government, is underpowered and ridiculously slow. I ran out of patience. But the info is there.

                      --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by cacole on Tuesday, February 25, 2014 8:46 AM

If the OP really must have answers to his questions he should contact someone who works for or with the FCC on licensing matters, because it seems that the rest of us are just speculating.

 

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Posted by mlehman on Monday, February 24, 2014 1:41 PM

CSX Robert
...all radio transmitter DCC equipment falls in the second category.

I think there must be something more than just being a transmitter that requires an ID number. I know there are Part 15 transmitters that require no licensing and -- at least in the past -- I don't remember them having an ID number if the output was below a certain tiny ERP.

But the rules are extensive and not really clear without an expert to assist. They're here:

http://www.ecfr.gov/cgi-bin/text-idx?SID=b8ef5f2f312cb0caa87ca513d49262d3&tpl=/ecfrbrowse/Title47/47cfr15_main_02.tpl

Mike Lehman

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Posted by CSX Robert on Monday, February 24, 2014 11:56 AM

gigasaurus
Correct me if I'm wrong, but isn't there a difference between "complying with FCC rules" ( putting a statement on your product that says you comply) and going through the FCC certification process (obtaining your FCC ID number which gets stamped on the product as a number). And from what I'm gathering, most (or all) DCC equipment falls into the first category. Does this sound right?
 

To put the statement on your product, it is supposed to be certified, but there are two different certification processes.  Unintentional transmitters are supposed to be tested and certified, but they do not get an ID.  Intentional transmiters go through a much more rigorous and expensive process and do get an ID number.  Most non-radio DCC equipment falls in the first category and all radio transmitter DCC equipment falls in the second category.

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Posted by cacole on Monday, February 24, 2014 11:38 AM

I can find no FCC ID number stamped on any NCE radio throttles, receivers, or the main DCC PowerHouse Pro box, or mentioned in any of their supporting documentation.

That's not to say they don't have one; just that it is not marked on their products.

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Posted by gigasaurus on Monday, February 24, 2014 11:25 AM
Correct me if I'm wrong, but isn't there a difference between "complying with FCC rules" ( putting a statement on your product that says you comply) and going through the FCC certification process (obtaining your FCC ID number which gets stamped on the product as a number). And from what I'm gathering, most (or all) DCC equipment falls into the first category. Does this sound right?
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Posted by CSX Robert on Monday, February 24, 2014 11:15 AM

cacole
...Only radio throttles must comply with FCC rules...

 

No, virtually all consumer elctronics must comply with FCC rules.

 

gigasaurus

 

So it sounds like most (if not all) DCC components (including wireless throttles) are self certified (and don't involve an actual FCC id number assignment)...

 

 

Radio throttles do have to get an FCC ID number, and that can get quite expensive.

 

In short, all the components have to comply with FCC part 15 regulations, but only the radio components require the extensive and expensive testing and review to get a FCC ID number.  These are covered under separate sub parts of part 15: B for unintentional radiators(non radio components) and C for intentional radiators(radi ocomponents).

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Posted by cacole on Monday, February 24, 2014 11:08 AM

The power that may be radiated by radiio throttles is very miniscule, so their range is limited to probably less than 100 feet.  Most operate in the 900 MHz range which is the frequency band allocated by the FCC for ground radio control devices.

 

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Posted by gigasaurus on Monday, February 24, 2014 10:52 AM

Thank you very much for the responses. So it sounds like most (if not all) DCC components (including wireless throttles) are self certified (and don't involve an actual FCC id number assignment). The 10K cost I mentioned was based on numbers I received from a company that has been involved in a number of FCC approvals for intentional radiators, which seems to be in line with numbers listed on SparkFun.com:  https://www.sparkfun.com/tutorials/398.  Thanks again for the information.

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Posted by cacole on Monday, February 24, 2014 9:08 AM

Only radio throttles must comply with FCC rules.  The following legalese statement is from the North Coast Engineering ProCab Wireless Supplement:

"The RU01-Pro, RU01-4/5 and RB01 wireless adapters for NCE cabs are RF products and may only be used in countries in which the units have been Type Approved or Certified for sale and operation.  Use of these products in countries where they are not certified may result in interference to other critical radio services and legal penalties.  (Current +countries of certification:  USA, Canada, Australia)

"This device has been tested to comply with Part 15 of the FCC rules.  Operation is subject to the following conditions:  (1)  this device may not cause harmful interference and (2) this device must accept any interference received, including interference that may cause undesired operation."

So the FCC never actually tested and approved the throttles, but relied on NCE's certification that they comply with FCC rules.

As far as the quesiton of cost of FCC certification, the OP will need to check with the FCC Rule 15 and see what their current filing fee amounts to.

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Posted by mlehman on Monday, February 24, 2014 7:57 AM

gigasaurus
I'm more trying to understand on the business end whether every manufacturer who makes DCC products standardly pays the $10,000 cost of obtaining an FCC ID number, or if they just state that it is in compliance.

Not sure where the $10k for a FCC ID comes from? Could you provide a cite?

Commerical licensing for broadcast might be costly, but that's because it uses spectrum, where only one party can effecitevly occupy a freq at a time. Part 15 assumes that muliple users will be present and that the signals will meet the standards to limit interference to other users. This can range from very low power broadcasting to things like DCC wireless. There is no actual Part 15 license, just that the manufacturer ensures it is something that complies but does not need a license if it's in compliance.

From the ARRL in plain English: http://www.arrl.org/part-15-radio-frequency-devices#Authorization

Many people think that FCC regulations require that these devices all be tested by the FCC, but in reality, few devices must actually undergo FCC testing. In most cases, the requirements are met by the manufacturer testing the device and either keeping the test results on file or by sending them to FCC, depending on the type of device involved.

Mike Lehman

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Posted by zstripe on Monday, February 24, 2014 6:46 AM

Gigasaurus,

What to do some reading? The first paragragh, indirectly relates to DCC:

http://www.fcc.gov/business-licensing

FRANK

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Posted by betamax on Monday, February 24, 2014 4:27 AM

It means that it complies with the rules.  It also has to be tested to determine it meets the requirements, before you get the ID number.  In other cases, you may have to demonstrate that it meets the requirements before being able to sell the device and include the usual statements about interference.

Even remote controls will have those statements about compliance on them, because digital electronics can create a lot of interference, and they want to insure it doesn't cause problems with something else by limiting the emissions from the device to certain level.

The best people to answer the question would be the manufacturer, and the appropriate regulatory agencies, in that order.

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Question about DCC and FCC
Posted by gigasaurus on Monday, February 24, 2014 2:40 AM

I read that DCC electrical components "comply with part 15 of the FCC regulations" and I'm curious: does this mean that DCC equipment is FCC approved and has an FCC number listed on it, or does this mean that DCC components don't send out enough signal to interfere with anything and so (on the honor system) the manufacturer is stating that the component "complies with" part 15 and does not cause interefence?

I'm not asking this because I have any suspicions that they do or don't - I'm more trying to understand on the business end whether every manufacturer who makes DCC products standardly pays the $10,000 cost of obtaining an FCC ID number, or if they just state that it is in compliance.

Does anyone have any packaging for a DCC product with an FCC ID number listed on the package (or device)?

I appreciate any insight into this.

 

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