Leader

Collapse

Announcement

Collapse
No announcement yet.

Freq under 300 Hz..

Collapse

300x250 Mobile

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Freq under 300 Hz..

    O.K.
    So I have to take this cert exam....I'm usually on the giving end rather than on the receiving end...

    I have taught Pre, grad and post grad electronics,for well over 16 years with X2 that # of years of experience..Held an advanced class, hold a first class phone license (FCC), ISCET, blah blah,,, my Heavy subject I teach is typically R.F.comm.. both lecture and lab...

    The reason for the above gas was just to give you an idea on which "slot" I fall into...I would think that history stamps me w/ a relative low Q factor ( Width, not depth of knowledge) on the X axis of of this thing we call electronic comm...

    Anyway I came across this multiple guess Q:
    It went kinda like this...

    Comm Tx utilize frequencies below 300 Hz for:

    assumption: this is a half duplex config... (note the original Q did not refer to a medium of comm or a reciever...)

    1) selective calling ( whatever that means, I took it as a comm channel utilizing or needing a P.L. to activate...using the tradition combination of two tones...(DTMF)

    2) subliminal coding..(well I knew that was a bucket full of crap)

    3) Station I.D. ( Well as far as I know this is still done in tha' traditional way of C.W. (about 20 WPM generally being the standard)......Or....

    4) Correcting the carrier frequency... ( well that would be just fine as candy except P.L.L. uses a D.C. voltage ripped from a common thingy called a low pass filter to correct said freq. via a comparator to re-adjust the VCO output...

    My assumptions and FCC definitions:

    - The human voice freq's fall between 300Hz and 3 KHz.
    - each PSRS, NBFM channel is 5 KHz in B.W.
    - each channel has a guard band of 1 KHz above and below the assigned freq.(centre freq)


    So ??? any of ya's geniuses wanna' give me an opinion and why??

    Oh yea, any of your agencies still operate around the 54 MHz 6 meter region?

    One more thingy.. if any of ya'll have any q about weird stuff, dealing with R.F. propagation,IE:, why does my HT werk @ this ditch or cornfield one day and not the next?, why this freq of operation?, why TDM instead of FDM, wht do i hear agency XYZ sometimes", the q you were curious about but afraid to ask,,,etc blah blah blah, feel free to inquire..I answer these type of Q for a living..

    Sully
    Last edited by asullivan; 03-13-2011, 10:56 PM.
    Originally posted by mookster
    Sully, usually I hafta glance over your posts cuz my brain would have issues with the imagery you portray, however with that one I get it. I agree one hundred percent with ya.
    Originally posted by CityCopDC
    I swear to god you are not human. I know a rogue VI when I see one.
    Originally posted by OfficerDotCom
    I think no one is probably happier than Sully and I that we ARE NOT the same person.(seriously thanking God for that one).
    -Frank




    Old Physicists neva' die, they just hop on a horsey and fly away inta' an infinitely massive black ho ...

  • #2
    WHAT...in the hell are you talking about?????

    I knows it's bad when you answer a question with a question.....sorry sully...I's got no answer for ya'll.

    SOmeone else wanna give it a try????????????????????? I knows ask Monty! Monty's a genious!

    I's think you got a case of valley fever.....where is trig?
    This profession is not for people looking for positive reinforcement from the public. Very often it can be a thankless job and you can't desire accolades, because those are not usually forthcoming. Just do your job to the best of your ability and live with the decisions you've made.

    Comment


    • #3
      Originally posted by deputy x 2 View Post
      WHAT...in the hell are you talking about?????

      I knows it's bad when you answer a question with a question.....sorry sully...I's got no answer for ya'll.

      Someone else wanna give it a try????????????????????? I knows ask Monty! Monty's a genius!

      I's think you got a case of valley fever.....where is trig?
      Officer....

      I am merely trying to establish via elimination a probable correct answer to a stupid multiple guess question regard'in' R.F. Transmission.... Ahh Ha!! Ya see your question helped a tad.. the original q said Frequencies below 300 Hz....That to me indicates it cannot, no way, no how be D.C. and there has to be more than one (freq) hence the pluralization....

      And NO the major could not, I wud assume help da' Admiral wid dis' Q for da' major is a Mainframe, lenix, Analytics, Queuing, Cryptology, Linguistics, believe me I know da' major very well God bless him.....I could smoke him in a microsec in R.F, any aspect
      I say without any reservation, just da' facts jack....

      And Trig is on a assignment....Or he betta' be..!!

      And neg on da' valley feva' dat $h1T runs from da' professor, I say.....and if some nut can crack dis' one a got a few more..... bad thang about these Q is they are not math based.....Made fer hillbillies I 'spose....
      Last edited by asullivan; 03-13-2011, 09:08 PM.
      Originally posted by mookster
      Sully, usually I hafta glance over your posts cuz my brain would have issues with the imagery you portray, however with that one I get it. I agree one hundred percent with ya.
      Originally posted by CityCopDC
      I swear to god you are not human. I know a rogue VI when I see one.
      Originally posted by OfficerDotCom
      I think no one is probably happier than Sully and I that we ARE NOT the same person.(seriously thanking God for that one).
      -Frank




      Old Physicists neva' die, they just hop on a horsey and fly away inta' an infinitely massive black ho ...

      Comment


      • #4
        Thanks for the explanation...but I still can't help you.

        Trig on assignment without you?
        This profession is not for people looking for positive reinforcement from the public. Very often it can be a thankless job and you can't desire accolades, because those are not usually forthcoming. Just do your job to the best of your ability and live with the decisions you've made.

        Comment


        • #5
          Originally posted by deputy x 2 View Post
          Thanks for the explanation...but I still can't help you.

          Trig on assignment without you?
          Yea' da' playboy,,,errrr correction,, horse,,,...NYPD snapped a pix of him...you can see it you know where...
          Originally posted by mookster
          Sully, usually I hafta glance over your posts cuz my brain would have issues with the imagery you portray, however with that one I get it. I agree one hundred percent with ya.
          Originally posted by CityCopDC
          I swear to god you are not human. I know a rogue VI when I see one.
          Originally posted by OfficerDotCom
          I think no one is probably happier than Sully and I that we ARE NOT the same person.(seriously thanking God for that one).
          -Frank




          Old Physicists neva' die, they just hop on a horsey and fly away inta' an infinitely massive black ho ...

          Comment


          • #6
            # Freq under 300 Hz..

            As you mentioned in parentheses for # 1, I suspect that they are referring to analog PL tones. The highest one that I have used is 254.1 hZ, thus by definition it is below 300 hZ.

            Comment


            • #7
              Originally posted by Jim1648 View Post
              As you mentioned in parentheses for # 1, I suspect that they are referring to analog PL tones. The highest one that I have used is 254.1 hZ, thus by definition it is below 300 hZ.
              Yes, Yes indeed Deputy,

              CTCSS, the highest is indeed 254.1 Hz... single tone - sub adible, yes.......

              BTW... just fer trivia sakes..da' FCC defines the human voice range between 300 and 3 Khz...So with a 1 Khz guard band below and above a nice round bandpass wud be 5 Khz fer.. 2 way comm..
              Last edited by asullivan; 04-22-2011, 04:09 PM.
              Originally posted by mookster
              Sully, usually I hafta glance over your posts cuz my brain would have issues with the imagery you portray, however with that one I get it. I agree one hundred percent with ya.
              Originally posted by CityCopDC
              I swear to god you are not human. I know a rogue VI when I see one.
              Originally posted by OfficerDotCom
              I think no one is probably happier than Sully and I that we ARE NOT the same person.(seriously thanking God for that one).
              -Frank




              Old Physicists neva' die, they just hop on a horsey and fly away inta' an infinitely massive black ho ...

              Comment

              MR300x250 Tablet

              Collapse

              What's Going On

              Collapse

              There are currently 5253 users online. 328 members and 4925 guests.

              Most users ever online was 26,947 at 07:36 PM on 12-29-2019.

              Welcome Ad

              Collapse
              Working...
              X