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Thread: Source for ambiguous exam questions- CCTV maximum length

  1. #11
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    Resolution has no bearing on the maximum distance without installing an amp
    Well, yeah with analog baseband video cable length certainly does affect resolution. The longer the run the more the high frequencies are attenuated, the lower frequencies not as much. Fine detail is contained in the higher frequencies of the 6Mhz bandwidth so as cable length increases the bandwidth decreases and the picture gets blurrier. That can be compensated for with amplifiers that have more gain at 6 Mhz than at the lower frequencies (tilt). But I don't know of any for CCTV video.

    -Hal

  2. #12
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    You should see the exam I wrote this morning... One of the sections was visual identification of RF connectors, and the images were practically unrecognizable (probably a 5th generation xerox)

    BNC wasn't that tough because of the white ferrule, but boy did it take me a while to pick out the PL259.

    There was other stuff too, like they kept referring to OC-1 as STS-1 (which I've never come across before today, I only associated them because they had the same bitrate)

    I'm still kicking myself for the one answer I realized was wrong about 2 minutes after finishing the test: When asked for the number of PCM bits per sample, I chose 16 (I was thinking 16-bit digital audio) but in telephony the usual is 8 bits x 8000 samples/sec = 64kbps

    3 hours allotted for the test, 3/4 of the questions in 45 min (easy) another 45 min for the remainder. Results in 2-4 weeks.
    "The Doppler effect means red lights will appear to be green if you drive fast enough..."
    1) Wait for disaster 2) Determine it's not your fault 3) Blackmail the culprit 4) Profit

    Caution: Classless when exhausted from a tough day at work, may attempt to compensate with poor humor and Christmas cheer...

  3. #13
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    A few more questions if I may-


    Does everyone here through their state have their license test for what ever trade ( Elec., Plumbing, Heating, Telephone) administered by a company called PSI out of Las Vegas?


    What is the procedure to challenge the CT State Occupational Licensing / Elec Board verbally/ in person? Has any one done this recently and would be willing to lend me their knowledge?


    If you are the electrician from NY state who in the 90's sued the state (and won) because CT said you needed to live in CT to take the E1 test I want to speak to you!


    Not sure how to explain this with out sounding like a raving idiot (Plus my head is on fire from this morning and the ludicrousness of how the exam process has changed in 20 years!) Below is the EXACT question for a C5 exam in CT that I of course got wrong.


    I believe that my next recourse is legal action and that through discovery I can show that the other questions are equally ambiguous and have no bearing on ones' knowledge and ability in the low voltage / communications / electrical trades to better provide safe contracting services to the people in the State of CT.


    If any one has examples of more ambiguous and incorrect questions generated by PSI and the state elec board and is willing to assist I would be most thankful.


    15:41
    #6 What is the maximum length of a horizontal voice and data communication cable?
    Their answer 90 m


    My answer 100 m referring to CAT 5 ethernet at 10/100B -T speed

    May argument:
    I have a land line in my home. The central office is about 4 miles away. The nearest SLICK is over 1100 feet to the main road if you want to argue that this communication cable begins there.



    My cable modem is fed from even farther away.

    I have installed both single line phones and TDM phones well over 2500 feet on horizontal twisted pair at a warehouses that was almost a mile long and the phone at the farthest loading dock worked fine.

    I have installed RS 432? or is it RS 422? serial data for computing devices, machine control, printers and serial data communications well over 500 feet.

    We all know there are transatlantic cables under the ocean carrying voice and data for miles.


    Yeah Yeah I know EAI / TIA and manufactures' standards ' accepted' back when ethernet was the greatest thing since sliced bread that 100M was the maximum length to shoot for for 10/100 B-T Ethernet . Then some manufactures added don't forget the patch cables. Lets allow 10 m for the patch cord and the jack to the computer. Then some manufactures adopted 90m + 10m. Then some manufactures adopted..... and on it goes ever changing





    Thanx for letting me rant.


    Be Well






  4. #14
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    Rampage_Rick


    What state are you in? What license requires you to recognize coaxial / BNC connectors to better install a system that is safe from a building perspective and passes an electrical inspection? Or was this a test for like a manufacturing gig, job or university that wanted to be sure you knew your $^!†?

  5. #15
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    What is the maximum length of a horizontal voice and data communication cable?
    That really is a trick question. They are talking about the common practice of running CAT5 cables from a patch panel to wall jacks that can be used for either voice (analog or digital) or data. After some thinking you realize that you can ignore the voice part since data would be the limiting factor. The industry standard is 100m maximum length. The question does not say "run" which would imply only the premises cable so I would take "length" to include any patch cords. So my answer would be 100m too. I don't know where they came up with that 90m anyway. That's nearly a 30 foot difference which is a heck of a lot for patch cords.

    As to your other questions about taking action I wish you luck. Their tests need to be kept current, accurate and understandable.


    -Hal

  6. #16
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    Connecticut
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    Hi HBiss.



    >>The industry standard is 100m maximum length.<<
    Then we both just got it wrong.

    They need to be specific if they want to reference 10/100 speed CAT 5 from the 90's.



    >>>Speedskater
    >>> The answer might be: 1000 feet. That's the longest standard length of a roll of co-ax cable.<<<

    Wrong.



    Thank you for letting me rant.


    I am in better spirits. Recommended to myself that rather than writing a 10 page legal brief I might be better served writing a 10 page paper for the electrical board to review and PSI that clearly shows I KNOW MY SHIT! 20 years not so much as a broken a ceiling tile.

  7. #17
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    I'm right across the border in NY and we have no LV licensing requirement. Although I do no LV wiring in CT I have toyed with the idea of getting a CT C5 license. Thanks for jolting me back into reality.

    -Hal

  8. #18
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    Quote Originally Posted by 1.42_tera_dynes View Post
    ... >>>if they are going to ask questions like that they need to have study guides with the information the questions are based on<<<

    For $ you can get all that junk. Manufacture the cigarettes and sell nicorette. ...
    uhhh ... why not buy the guides (and the instructors guides while you are at it)

    That was my solution for both my PE ticket and EA ticket. In both exams, there were questions right out of the guide - only the numbers were changed.

    Fighting city hall is fun - making money is more fun.

    If you want to be a hero, join the appropriate organizations after you get your license and take on the Syndicate to your hearts content. I encourage you all I can. Someone has to do it. And I won't. My passion is collecting the money for an excellent, on-time, in-spec, in-budget, job.

    ice
    Harmless flakes working together can cause an avalanche of destruction

  9. #19
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    uhhh ... why not buy the guides (and the instructors guides while you are at it)
    That would be the easy thing to do except that I don't believe they exist for this exam. Wasn't that talked about early on? I think the OP was just assuming in your quote.


    -Hal

  10. #20
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    Quote Originally Posted by 1.42_tera_dynes View Post
    Rampage_Rick
    What state are you in? What license requires you to recognize coaxial / BNC connectors to better install a system that is safe from a building perspective and passes an electrical inspection? Or was this a test for like a manufacturing gig, job or university that wanted to be sure you knew your $^!†?
    Just got my certificate in the mail yesterday...

    "An Electronics Communications Technician is a person who installs, maintains, troubleshoots and repairs data and communication systems, equipment and cabling on computer networking, telephone, security and other related data systems."

    Name:  certificate.jpg
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    ITA issues all the trade certifications for the Province of BC (sparky, boilermaker, automotive technician, etc) I had some free time over the winter so I applied at the beginning of January to challenge this certification (it's normally a 3-year apprenticeship) Well it turns out that they're no longer offering apprenticeships for this program due to lack of demand, and it took months to get them to offer the test to me. I just checked and they don't even offer the option to challenge any more. http://www.itabc.ca/Page617.aspx

    It would seem that I am the last person in the province to get it...
    Last edited by Rampage_Rick; 06-06-12 at 04:16 AM.
    "The Doppler effect means red lights will appear to be green if you drive fast enough..."
    1) Wait for disaster 2) Determine it's not your fault 3) Blackmail the culprit 4) Profit

    Caution: Classless when exhausted from a tough day at work, may attempt to compensate with poor humor and Christmas cheer...

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