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Frequency tolerance certifcate proof

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#1 jimndfw


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Posted 17 October 2015 - 03:33 PM

The other day going thru some old box’s on the shelf I ran across the proof of the annual transmitter testing certification sticker for one of my old Civil Air Patrol < CAP > radios.  I seem to remember that I had to get them bench test annual to ensure they were within the frequency tolerance.


 I look at the part 95 rules, and came across these:


 §95.603   Certification required.


  1. Each GMRS transmitter (a transmitter that operates or is intended to operate at a station authorized in the GMRS) must be certificated.




§95.621   GMRS transmitter channel frequencies.


(a) The GMRS transmitter channel frequencies (reference frequencies from which the carrier frequency, suppressed or otherwise, may not deviate by more than the specified frequency tolerance) are 462.5500, 462.5625, 462.5750, 462.5875, 462.6000, 462.6125, 462.6250, 462.6375, 462.6500, 462.6625, 462.6750, 462.6875, 462.7000, 462.7125, 462.7250, 467.5500, 467.5750, 467.6000, 467.6250, 467.6500, 467.6750, 467.7000, and 467.7250.


Note: Certain GMRS transmitter channel frequencies are authorized only for certain station classes and station locations. See part 95, subpart A.


(b.) Each GMRS transmitter for mobile station, small base station and control station operation must be maintained within a frequency tolerance of 0.0005%. Each GMRS transmitter for base station (except small base), mobile relay station or fixed station operation must be maintained within a frequency tolerance of 0.00025%.




I am not seeing how often this need to be done? Does anyone have any ideas?

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#2 jwilkers


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Posted 17 October 2015 - 06:22 PM

I'm guessing the testing lab who reviews and issues the FCC ID will do this prior to certification.  Evidently, once a radio is certified, that's it.  Any subsequent production runs would be covered.


But we all know how "huh?" the rules are.

#3 PastorGary


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Posted 18 October 2015 - 09:13 AM

Since all of my Chaplain Responder equipment is both Part 90 and Part 95 certified (Kenwood), when we have our yearly Part 90 inspections, the Part 95 channels are automatically reviewed as well.    Just make certain that the service monitor/frequency counter that is being used to do these checks has, itself, been calibrated and certified by an appropriate calibration company and the certificate is valid.


These days, modern equipment frequency stability is usually not an issue and the same software that is used to program the radios has the TEST MODE built in for setup... at least for the Kenwood equipment that I own. 

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#4 Ezekiel


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Posted 07 November 2016 - 10:33 AM

OK now I am going to ask this, as I am very new and I guess lame in this subject.


Pastor Gary stated a yearly certificate.  and others are speaking about getting them certified.  If I am setting up a repeater system, either mobile or static do I need to have someone come out and certify them or do I dismantle them and take them to a radio shop that can certify them, and have my system down?  


I guess that I am a little confused still,  could be that it is early in the morning and not much sleep happened. 


I would a little more explanation if someone could for me please.  I get that the Ham Equipment needs certified bus not sure on that either. 



Thank you for any help that you can give me. 



#5 n4gix


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Posted 07 November 2016 - 10:52 AM

Tanner, there is absolutely no need for a GMRS licensee to have his or her equipment go through any form of "annual certification." However the licensee does have the ultimate responsibility to ensure that the transmitters remain within their certificated specifications.


These days, about the only time that might come into question would be if a radio had to be serviced for a problem, at which time the service technician doing the repair would make the requisite tests via their service monitor to ensure that it meets the specifications.

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#6 wqwj836



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Posted 30 November 2016 - 08:42 PM

To jimndfw: Remember that CAP is regulated by the NTIA for military and government communications - not the FCC. While the FCC certifies equipment for use in the various (civilian) radio services, it is actually NTIA, the Air Force, and CAP that determine what equipment can be used, certified, etc.


Reference capmembers.com under the Communications section (at the bottom) if you have access.

#7 jimndfw


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Posted 04 December 2016 - 12:39 PM



  I do want to thank you for you reminding that the NTIA, and US Air Force required the frequency tolerance check for the radios, it has been so long that I dealt with them rules and reasons we did it, that I just thought it rule for all services.


I like to take the best practice approach in following the rules, just for the record I am former CAP Wing ADC.


  The reason I was posting this question, was when I own a company, I had require my radio to certified yearly, and when I was in Public Safety Field, we all had to take radio's to the shop to get them check annually to ensure we are still in the tolerance of the frequency requirement.


 I just wanted to be sure that there was not some hidden rule or rules we operate in the GMRS/FRS service, that would cause me to be in some kind of violations. And if it was require, when it was required, ( AKA, how often)


 Of course, we all know well GMRS/FRS rules are (cough, cough, hack, hack,) written to understand, or interpret.... LOL


I hope you have a great day! 

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