Out of band for fire/ems/whatever.

Discussion in 'General Technical Questions and Answers' started by KC7YRA, Feb 5, 2008.

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  1. K7JEM

    K7JEM Ham Member QRZ Page

    This is certainly true. You do not gain any certification when a radio is operated outside of it's certified range. A radio certified for 148-174 cannot be certified if it is operating on 146MHz, regardless of tuning, since that frequency was never in the original manufacturers specifications.

    So the radio is NOT certified when operating on 146MHz, but is still certified when operating on 152 MHz, since that is within the certified range.

    But it doesn't need to be certified to operate on 146MHz, and the fact that it can operate there doesn't void its certification on 152 MHz, regardless of tuning.

    Lack of "certification" doesn't mean that it won't operate well, just that the paperwork was never done. Does anyone really think there would be any operational difference between a radio transmitting at 148.01MHz and one transmitting on 147.99MHz?

    And, since "certification" is done on an FCC service classification, EVEN IF a radio was certified for part 90 operation from 136 to 155MHz, it still wouldn't be certified for ham use on 144-148MHz, since amateur is part 97, and the certification does not include that FCC service.

    Joe
     
  2. WA0LYK

    WA0LYK Ham Member QRZ Page

    Thank you so much for your demeaning attitude and comments. I very much appreciate your rude comments because they simply indicate where you are coming from.

    You have no idea what my background is nor what my technical expertise is.



    You are exactly right in this, here is what Part 2 says. "2.908 Identical defined. As used in this subpart, the term identical means identical within the variation that can be expected to arise as a result of quantity production techniques."

    You may consider me confused between modification and alignment but I am not. You are saying that you can "align" a radio outside of the manufacturers instructions and that it is ok. It is not. If you use your own procedure for "aligning" a radio outside of its manufacturers specs, you are modifying the radio beyond what the manufacturer intended.

    Certification is more than a paperwork process. The very tests you mention means there is more to the process than the mere filing of paperwork with the fcc.

    According to the rules if the frequency band specified in the application is changed and done on purpose and with the agreement of the manufacturer, then it means "the equipment does not conform to the pertinent technical requirements
    or to the representations made in the original application" and the fcc can remove
    the radio's certification.

    In the end, you are recommending that folks trust you that you will not make their radios perform improperly when you "realign" them. Personally, I would not accept that unless you go through all the measurements to insure that the radio performs as originally designed in the radio service certification was applied for.


    Jim
    WA0LYK
     
  3. KA4DPO

    KA4DPO Platinum Subscriber Platinum Subscriber QRZ Page

    Precisely Jim. The design of the radio and the operating specifications within the design envelope must be taken into account when such changes are made. I'm certain Motorola published service bulletins that covered this procedure after the engineering department determined it was kosher.
     
  4. K7JEM

    K7JEM Ham Member QRZ Page

    This may be true. But realigning a radio is not changing a frequency band. Remember, we are not talking about trying to use this as a certified radio in the 2M (or whatever) band. You have made NO changes to the certification by realigning anything in the radio. Let me make this clear. EVEN REALIGNING A RADIO TO PARAMETERS THAT ARE OUT OF SPEC DOES NOT VOID THE CERTIFICATION. That is because certification is different than alignment. If you put the radio off freq, and over deviated, then it is out of FCC parameters. BUT IT DOES NOT BECOME DE-CERTIFIED. This assumes that the radio can be aligned back to it's original state, and you have made no modifications to certain circuits. This thing that you quote has to do with the whole certification of the radio product, not one individual radio. If the FCC finds (as they sometimes do) that a model of radio does not meet a certification parameter, they can pull the certification for that model.

    What parameter is changed by adjusting the VCO? Do you think the power out is going to change? How about the frequency stability? Maybe the modulation characteristics?

    What exactly are you thinking is going to change by adjusting a VCO coil by one turn?

    People are either qualified to do a proper alignment, or not. If you're not, don't do it. If you are, have at it.

    I am not advocating that anyone do anything, if they don't have the smarts, the technical ability, and the test equipment.

    I happen to have all of these things, however.

    Joe
     
  5. K9STH

    K9STH Platinum Subscriber Volunteer Moderator Platinum Subscriber QRZ Page

    "Certification" is the new "buzz word" meaning "type-acceptance". Actually, "certification" has a much broader meaning and the FCC has recently included what they used to call "type-accepted" in the broader scheme of things. You have to look at what the actual parameters of any particular "certification" to see what is actually required. The technical requirements of "certification" for 47 CFR Part 90 (and several other Parts) are exactly the same as when the process was called "type-acceptance". The FCC still uses "type-accepted" in some of the wording in various Parts of 47 CFR where no changes have been recently made.

    If you look at the alignment instructions for the vast majority of certified/type-accepted radios you will see that there is a procedure listed and no reference to any particular frequency (other than the "desired frequency of operation" or something similar to that). Therefore, if the procedure is followed and no component changes are made which modify the original values then there is no reason that certification/type-acceptance is violated. Many of the synthesized radios do require alignment if the desired frequency of operation is very far from the frequency used by the factory for alignment purposes.

    Now many of the "modern" radios will operate satisfactorily in the 2-meter amateur radio band even without any retuning at all. The same thing with the 450 MHz to 470 MHz radios where the FM portion of the 70 cm band is involved. It is also true with the 900 MHz band where the commercial equipment works fine in the amateur radio portion without any retuning.

    The fact that amateur radio equipment is not certified for use on commercial frequencies is for a number of reasons. First of all many amateur radio units do not meet the frequency stability requirements that commercial equipment has to meet. Next there are the modulation characteristics which are generally "tighter" in the commercial equipment. Then there are the "spurious emission" requirements that are generally "tighter" on the commercial equipment. Finally there is the fact that amateur radio equipment generally can have the frequency immediately changed from the "front panel".

    Now many certified radios can be readily "field programmed" by a numeric pad on the front of the radio. However, they have to have some sort of "fail safe" mechanism (i.e. removeable "plug") that has to be inserted before the unit can be programmed. Of course there are always going to be some people who circumvent those procedures. It is just that the manufacturer is required to make this as hard as possible to accomplish. A good example is the old Regency highband units that only required a jumper be inserted to allow "front panel" frequency control. It only took a short time before all sorts of people were adding a switch to the front panel to allow immediate frequency changes. The FCC soon "pulled" the type-acceptance on these radios.

    Now radios that require an external programming unit (either "stand alone" or by a computer interface) do not have to have such a "fail safe" device because the radio cannot have the frequencies changed without using the external device.

    When a 2nd or 1st Phone (and later the GROL) was required for doing any alignment of any type-accepted radio for use in a service requiring type-accepted equipment there was a very good possibility that the procedure would be done correctly. This is because the person doing the alignment, repair, installation, etc., had to certify in writing that the radio met the technical requirements of that particular service. This written certification had to be retained by the licensee of the commercial system until it was replaced by another certification on the same radio. For many years the units had to be recertified every 6 months, then the FCC went to a yearly requirement. Now days there is no requirement for a radio to be certified on any regular basis.

    Until around 1960 many units actually had a cover over the frequency adjustments and over the modulation adjustments through which a wire was inserted and a round lead "seal" was placed. The technician had a tool which installed this seal on the wire and that embossed a "mark" which could be traced to the individual licensed technician. This particular requirement was not in effect after I got my commercial license (September of 1962). However, I still have some of the unused lead seals in a box left over from when they were required.

    The wording in 47 CFR Part 2 is very general in nature. You have to go to the individual Parts for more specific information. Each radio service has different requirements both technical and operational. Now many are virtually identical but some services have requirements that are vastly different from the others.

    Glen, K9STH
    PG-10-23542 / PCIA 109494
     
  6. WA0LYK

    WA0LYK Ham Member QRZ Page

    I agree with most of what you say. If Motorola certified a handheld from 130 -175 mHz and provided the test results for this range, and then sells X model from 130 - 144, a Y model from 144 - 148, and a Z model from 148 - 175, then it's all the same radio, and "realigning" it for any spread within the certification is fine. However, if they certify a radio from 150 - 170 only, and you use your own procedures, beyond those of the manufacturer, to make the new range 144 - 164, or worse, 144 - 170, you have essentially modified that radio so that it no longer falls within the parameters that was represented to the fcc during the certification process.

    Will it work ok? Maybe. But I do know that pll's only have certain lock ranges. If you move the vco far enough to include the ham bands, who knows how it will react at the upper end of the range.

    A good question to answer would be if you purchased 1000 of them, did your own non-Motorola approved realignment as above, and sold them under the Motorola certification to a service requiring certified radios, would Motorola support you.

    Jim
    WA0LYK
     
  7. N4DES

    N4DES Ham Member QRZ Page

    If you were a Motorola Service Center (MSS) there is a good chance that your certification would be lost if the alignment/modification(s) was made public. If you weren't a MSS there is no way that /\/\ would support the practice.
     
  8. KC8TCQ

    KC8TCQ Ham Member QRZ Page

    I did some research, related to some radios someone dropped in my lap today. Motorola MT2000, various models, Anyway the 2 VHF models specs (from the facrtory) state they cover 136-174 Mhz, and two of the UHF models cover 403-470 Mhz.
     
  9. K7JEM

    K7JEM Ham Member QRZ Page

    We are not talking about a range change. That is a specific thing wherein parts are changed for different band segments, like Glen was talking about. Motorola used to sell different versions of their radios, some were 150.8-162, some were 162-174. These had the same active components, but some of the coils and caps were different to accommodate the different frequencies.

    If you take a radio that is 148 to 174, and it covers that whole area, then it is entirely possible to retune the VCO maybe about one turn or less, and pick up good lock down to 144. Now in doing this, you might lose the top few megs, maybe not. If the freqs you are using are in the 155 to 160 range, it will matter not that the VCO won't lock at 173, because you're not using it there.

    Now, you have extended the range of the TX, but you have not made a "range change" as defined by the manufacturer. The fact that the radio can now operate lower in frequency is of no concern to the certification, it remains as is, at 148-174, since you have not modified the radio. The certification is a piece of paper that states what the manufacturer wants, not what limitations the radio actually has.

    The radio is still not certified below 148, regardless of how well it works. But in our case, we don't care, because these frequencies don't need certification. Once we switch to a 155MHz channel, the radio is back in certified territory, and in a certified service.

    The radio can be certified on one frequency, but not on another, in the same frequency range.
    But Motorola is not the FCC. Their internal policies about how they handle situations are bizarre, to say the least. But to answer your question, there is no certification problem with the FCC, as long as you don't change out parts.

    Joe
     
  10. WA9SVD

    WA9SVD Ham Member QRZ Page

    Then provided they have not been "modified" in any way, and you can get someone to program them for you, there should be no problem using them in their intended Service(s) AND the appropriate Amateur band. THAT doesn't affect the certification at all. The Amateur allocation luckily falls INSIDE the frequency range specified by the manufacturer under the authorization of those radios. They don't need to be "realigned" or have the VCO "adjusted" to cover the Amateur band, they can do it with the same programming used to select frequencies within their respective services. But that isn't what I understand JEM to be saying.
     
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