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[aprssig] FRS & Type Acceptance WAS: Clubs, FRS ...teams

Alex Carver kf4lvz at yahoo.com
Sat Sep 3 20:10:39 UTC 2011

Steve Noskowicz wrote:
> Hi Alex,
>    Not quite.  There are several fine
> points, but I'll try to keep it short and may appear to miss
> some significant details in the sprit of an overview.
>   I did see that part of Bob's comments. I won't go
> into full detail unless you want, but there is a fine point
> I'll clarify.  Please accept this as friendly mentoring
> (for everyone reading).  I hope my comment to Bob
> didn't sound like I was jumping on him. I did think his idea
> was clever, as I frequently do of his ideas, and couldn't
> resist opportunity for the pun.
>   Also, I am not an FCC nazi type.  I'm only
> pointing out a technicality and stand by it based on my
> experience managing a validation/certification department at
> Motorola. Some of the FCC rules do appear to conflict with
> others.
>   To the letter of the law, the 200' line is not an
> approved accessory and its use is unapproved. I am pretty
> sure that that part of the (applicable) rules makes no
> distinction as to whether or not the device is
> transmitting.    It is not just transmitters that
> require careful desigh when it comes to interference
> portential.   [to be clear - I am not
> bothered in the slightest by Bob doing this it]
>   Type acceptance is no longer the accepted
> terminology.  Radio equipment manufactured for use in
> the various services in the U.S. is now "certified" to meet
> the rules/laws.  The equipment receives a "Grant of
> Certification" from the FCC. 
>  When required, the certification process is the rigorous
> measurement of a typical unit for very extensive, specific
> and detailed parameters that must be measured to show they
> meet all of the FCC requirements for use in a specific radio
> service.  This includes both transmitter and receiver
> parameters.   In addition, the radio must
> also meet the Part 15 limits of potentially interfering
> radiation.  In fact, and in principle, *everything*
> must meet Part 15 limits, even power lines.
>   FRS radios are not certified in this manner under
> any service.  They (the ones I have) are Part 15
> intentional radiators of RF.  They are only certified
> to not radiate harmful energy above Part 15 limits. 
> None of the transmit or receive parameters are certified
> (except, perhaps tx power - I haven't examined any FRS
> specific requirements).
>    For certification, a 'typical' unit is
> put in a special chamber, operated under 'normal' conditions
> with accessories (this could take several test runs with
> different accessories) and the radiated emission are
> measured across the RF spectrum.  
>   Adding any "unapproved accessory" increase the
> likelihood that the Part 15 limits will be exceeded. 
> It could be a processor clock in the radio that 'leaks' to
> the cable. A 200' cable can cause it to do so and since it
> was not measured for certification with such a cable
> attached, it is clearly outside the letter of the
> rules.  Whether it *will* cause interference is another
> matter completely.  It is not certified and not
> included in the Grant. 

I do understand what you're saying including Part 15 which governs nearly every piece of electronics around.  I'm not taking offense but I think there's enough gray areas within the rules that it could very easily be argued in front of the FCC that his modification is acceptable.  For that argument I would present the following:

15.1b appears to state that an RF device may violate Part 15 if the FCC certified it and licensed it otherwise.  However 15.5a appears to contradict that statement though it references a section that doesn't exist (90.63).

15.23 exempts home-built devices.  This is probably a little gray because it's a combination of a commercial device with a home-built modification.  

95.194 governs the FRS units and does mention that you may not attach an apparatus to an FRS unit that has not been certified as part of that unit.  However, see the entry below about 95.603.

95.129 which governs the GMRS portion of Personal Radio and the FCC explicitly singles out transmitters and not the whole unit.  Certification of a GMRS capable radio applies only to its transmitter according to that section.  The grey area comes in the dual-use radios that can operate on GMRS and FRS simultaneously.  If it can do both and there's a license to operate GMRS then it is likely that 95.194 does not apply and Bob's speaker wire and power cord are not covered because such a modification is not considered by 95.129.

95.401 defines FRS to be a Citizens Band Service (95.401b) but it does not specify GMRS as a Citizens Band because of the GMRS licensing requirement.

95.601 explicitly references only the transmitter for any Personal Radio Service device.  It also explicitly includes FRS in the Personal Radio Service.

95.603 specifies that an FRS unit must be certified but then defines an FRS unit to be a transmitter.  Therefore the use of "FRS Unit" in 95.194 applies only to the transmitter portion.

95.605 defines the certification procedure and specifies only the transmitter.  Chapter 2 Subpart J that it references (2.907) only specifies that certification is based on test data and applies to other identically produced devices.

95.607 prohibits the addition of external connections to a CB transmitter but this is a gray area because 95.669 restores the provision.

95.635 specifies the unwanted radiation from any device with and without external connections but again only references the transmitter portion of each device.

95.669 specifies the external controls that may be available on a CB transmitter.  This is another grey area because CB Service was already defined to include FRS so a CB transmitter could be construed to include FRS as well though it now conflicts with 95.194 and 95.669 is conflicting with 95.607.

Given all the above I would argue to the FCC that Bob's modification (not withstanding his Part 97 license) is a home-built device and therefore Part 15.23 applies assuming he has shown the use of good engineering practices (such as a choke on each wire as close as possible to the radio) and that the modification is permissible because it applies only to the receiver rendering most if not all of Part 95 null as he is not exercising the transmitter portion of the radio.  If Part 95 was included, there are enough exceptions in the rules to allow the basic modification that Bob performed consistent with the rules (even in the face of some contradictions).

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