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Thread: "How To Build a $19.00 Police Scanner"

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  1. #1
    Master Navigator koØm's Avatar
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    "How To Build a $19.00 Police Scanner"

    Has anyone here successfully used a SDR to receive Trunked Tracking messages?

    I started out here: https://sites.google.com/site/policescannerhowto/. I also browsed the links provided for support information.

    I have a working install of SDR# with a Trunk Tracking plugin but, when tuned to control frequency and, I am seeing digital signals but, the receive is not tracking and decoding them. I have two dongles, one for the "Signal" receiver and one for the "Control" receiver.

    The article was written in 2013, in the process of trying to figure why my install wasn't decoding, I ran across this: If you’re a glutton for punishment, continue with this doc:


    Back in my working days, I was the fellow that the folks called to untie knots that nobody else could not untie; I was not deterred by the warning.

    But, Dayum, he was right.

    I am soaking up information from http://forums.radioreference.com/sof...n-updated.html as you can see, this thread was started in 2013. I have spent multiple hours standing here with "Virtual Cables", Digital Speech Decoder, Trunk-Tracker; something small is missing, I have re-read the pages and retraced my steps.

    It's been on hold for the last week, I guess I'm ready for more Sado-Masochism.

    "Help!"

    .


  2. #2
    'Grumpy old bastid' kb2vxa's Avatar
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    Oh no, you must be a sadomasochist if you think you can get anything useful from the Radioreference forums. If you really are a glutton for punishment keep at it, I gave up trying to reason with know-it-alls, pin heads, microminds and bricks around the time the thread started. I changed my bookmark URL from forums to the only useful part of Rat Reference, the database.
    "The universe is under no obligation to make sense to you."
    Neil deGrasse Tyson

    73 de Warren KB2VXA
    Station powered by atomic energy, operator powered by natural gas.

  3. #3
    Orca Whisperer n2ize's Avatar
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    Quote Originally Posted by kb2vxa View Post
    Oh no, you must be a sadomasochist if you think you can get anything useful from the Radioreference forums. If you really are a glutton for punishment keep at it, I gave up trying to reason with know-it-alls, pin heads, microminds and bricks around the time the thread started. I changed my bookmark URL from forums to the only useful part of Rat Reference, the database.
    Very true. I don;t even remember what my username and password was over there. As far as p0olice scannning goes my old vacuum tube "vhf low" receiver works fine.
    I keep my 2 feet on the ground, and my head in the twilight zone.

  4. #4
    Master Navigator koØm's Avatar
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    Quote Originally Posted by kb2vxa View Post
    Oh no, you must be a sadomasochist if you think you can get anything useful from the Radioreference forums. If you really are a glutton for punishment keep at it, I gave up trying to reason with know-it-alls, pin heads, microminds and bricks around the time the thread started. I changed my bookmark URL from forums to the only useful part of Rat Reference, the database.
    They have over 900,000 paid subscribers. If I dig deep enough and shift through the chafe and sludge, I'm pretty sure that I can come out of there with something useful; I'm hanging out in the Trunked Radio and Digital Speech Decoding forums, I haven't made it to the Amateur Radio section yet.

    They are a little "High-and-Mighty" over there, one forum "Sticky" exclaimed, "If you don't know how to 'Compile' then, you shouldn't be in that particular forum" or even try to utilize the programs discussed in the threads.

    .


  5. #5
    Master Navigator koØm's Avatar
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    Interesting



    .


  6. #6
    Master Navigator koØm's Avatar
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    Quote Originally Posted by koØm View Post


    "Help!"

    .
    This is not a "Plug-n-Play" project to be undertaken by the average "Appliance Operator".

    I followed the 2 year old instructions to the letter but, the SDR would not performed as noted in the instructions; I retraced every step. I doubled checked my work. At this point, I backed up and started reading the information provided in the supplemental help links. After a minimum of 25 hours (over five days) of reading and fiddling around with the SDR# Trunk Tracking project, I walked away from it for a week.



    <rant> "Open Source Code" -- Everybody and "his brother" seem to be able to write code and proudly document it on the Internet; there are plugin for this and plugins for that but, they are scattered all over the W.W.W. and, anyone is free to modify the code; this lead me down a number of dead end roads because what worked with one version of the code did not work with a different version of the code. Eventually, even I ended up modifying .xml configuration files and downloading 5 different release versions; substituting one with the other until I found the right combo. The problem: "Lots of dead limbs and rotten fruit hanging off the tree"; nobody around to organize the Incubator.</rant>

    Seven days pass before I jump back in, for three days, I read endless links and I watched a YouTube Video on "How To" in "Stop-motion" to analyze every comment and move made by the author. All of the "Instructions" on the web seems to gloss over some very important points needed to make this thing work. By the fifth day of this cycle, I had it decoding individual digital feeds for the local trunked system but, the radio would not follow the trunking commands. I took another week off.

    A couple of days ago, I started the final push; I entered the Control Frequency into the radio and noticed that it did not line up with the calibration of the radio. When I properly calibrated the SDR Dongle freq to the radio, the Trunk tracking started trying to control the secondary receiver but could not. The secondary radio was set to be parked on a control channel. I shifted the park frequency and, the Tracking control kicked in and started bouncing the receive frequencies around. The receiver dongle needed to be calibrated to the right frequency and now, the setup is working.

    There is a sequence that the programs needed to produce output and function must be linked together with virtual audio cables and started up in a certain order to make it work; once running, you don't want to turn it off because it is not like a Uniden scanner that you just "Turn the knob" and get reception.

    .


  7. #7
    Whacker Knot WØTKX's Avatar
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    Control Without Knobs. Kewl!
    "Where would we be without the agitators of the world to attach the electrodes
    of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman



  8. #8
    Master Navigator koØm's Avatar
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    Quote Originally Posted by WØTKX View Post
    Control Without Knobs. Kewl!
    Would really rather have a scanner with knobs to do the work of the two Linux based Digital Speech Decoders + Trunk-Tracking plugin + 2 SDR instances running at the same time but I'm not spending that kind of money on something that is receive only!

    .


  9. #9
    Whacker Knot WØTKX's Avatar
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    Scanners are OK, but even at work they are using Internet feeds now for the communication center.

    I never really "got' the scanner bug, but I sold/supported them with enthusiasm for customers.
    "Where would we be without the agitators of the world to attach the electrodes
    of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman



  10. #10
    Master Navigator koØm's Avatar
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    Quote Originally Posted by WØTKX View Post
    Scanners are OK, but even at work they are using Internet feeds now for the communication center.

    I never really "got' the scanner bug, but I sold/supported them with enthusiasm for customers.
    They were "interesting" for a while, they allowed you to eavesdrop on the local neighborhood but, in 2010 the whole city and county went to a 800 MHz Digital Trunk system and every VHF and UHF scanner in the city became useless, people were giving them away.

    I sold all mine on eBay.

    I enjoyed the challenge of making the Software Defined Radio follow and decode the "secret" channels that the police use; the fire dispatch is especially informative, but I get pretty much of the same info off my Twitter feeds from the TV channels (you know that they are breathlessly monitoring the frequencies for "News").

    .


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