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− | Over the Christmas holiday I decided to do something useful for once.
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− | After that thought passed I just went ahead and played with my radios.
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− | More and more radios in my area seemed to be going to trunked systems, and
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− | while I LOVE my [[IC-PCR1000|PCR-1000]] I was thinking I might also pick up an Optocom to
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− | followed the trunked systems.
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− | While doing research on trunked systems I came across the program called Trunker.
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− | Trunker is a public domain program that allows you to follow Trunked
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− | systems.
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− | It uses 2 radios. One radio needs its discriminator port connected to a
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− | "Hamcomm" data slicer (more about this later). This radio is tuned to the
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− | digital control channed of the trunked system. The control channel tells
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− | the radios what frequencys to change to. It also transmits various
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− | information about each transmission and information about the trunked system
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− | itself. Decoding this data allows Trunker to display information about the
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− | system and each transmission. Since this data allows trunker to know each
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− | frequency a converstaion is on, it also allows it to tune a computer
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− | controlled scanner to the correct frequency to follow a conversation, this
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− | is the second radio. The latest version of Trunker (v371) supports the
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− | PCR1000 as the scanning radio. Yea! The PCR1000 could also be used as the
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− | data channel radio using its discriminator port.
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− | I have done it both ways and it actually works! I began by building the
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− | Hamcomm interface and connecting it to the PCRs discriminator port. To my
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− | amazement it worked. I was also able to find quite a number of Trunked
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− | systems in my area (6 systems so far) by scanning for data channels and
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− | letting Trunker decode information about the system. It worked great. Next
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− | I took apart my BC3000 and tapped into it's discriminator port. This allowed me to use the
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− | BC3000 to decode the data channel and the use the PCR as the audio scanner.
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− | The whole thing works and it only ended up costing about $10 worth of parts
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− | from Rat shack.
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− | I figured I would type up how it was done so that if anyone else wanted to
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− | do it they would have everything in one place. This is a great first
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− | project if you have never build anything before and the Hamcomm interface
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− | you build is supported by many other digital mode decoders.
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− | First, download the Trunker software and read the instructions. Read the
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− | instructions! They are well written and explain everything about the
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− | program. You can find the latest versions on the [[Trunker]] article.
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− | Next, build the HamComm "data slicer" interface. There are several designs that can be found
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− | on the [[Data Slicers]] article.
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− | I followed the plans in the colored picture. I also chose to modify this
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− | plan slightly by tying the CTS pin (pin 8 on a 9 pin connector) to DSR (pin
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− | 6 on a 9 pin connector). This is because some programs want to see the data
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− | on CTS, while some want to see it on DSR. If you look at the black and
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− | white plan on the previous web page you will see it shows pin 6 of the 741
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− | going to either CTS or DSR. The color plans shows pin 6 of the 741 going to
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− | DSR. I chose to make it go the both CTS and DSR.
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− | Trunker has an environment variable that allows you to choose, some other
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− | programs do not.
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− |
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− | Next locate a Trunked systems control channel.
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− | Information on trunked systems frequenys and group IDs in your area can be
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− | found on the RR database. The link is in the 'quicklinks' on the left frame.
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− | You can find control frequencys by plugging in all the frequencies of a
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− | system and then
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− | checking them for a digital signal.
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− | Once the scanner is locked on to the control channel start trunker.
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− | I use the following environment variables in my trackenv.txt:
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− | TRACKSLICERPORT=COM1 <br>
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− | TRACKSLICERPIN=DSR <br>
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− | TRACKSLICERMODE=INVERT <br>
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− | TRACKSCANPORT=COM4 <br>
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− | TRACKSCAN=PCR1000 <br>
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− | TRACKSCANBAUD=9600 <br>
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− | TRACKSCANPARK=811.0000 <br>
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− |
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− | In my example, I have my data slicer circuit connected to COM1 and the
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− | PCR1000 on COM4. You must add the TRACKSCANBAUD=9600 line to the example
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− | trackenv.txt that comes with Trunker or the PCR1000 will not work. It only
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− | seems to work at 9600.
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− | Trunker should start and begin adding frequencys to the list. The field
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− | labled "SysId" should fill itself out immediatly. The field "Flavor" also
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− | should be filled out, and you should see some value in the "Acc" field. Acc
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− | stands for accuracy of decoding the data channel. On the strongest system
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− | in my area trunker will decode with 98% accuracy over 24 hours. Not bad.
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− | The worst accuracy is a system some distance away, with that I get around
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− | 60%, Trunker still tracks the calls, but the voices themselves have some
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− | static in them. Trunker considers anything over 80% high quality.
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− | You should also start hearing conversations and seeing talk groups appear on
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− | the screen. Just follow the instructions that come with Trunker and you
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− | will be able to edit the talk groups so the Trunker will show you who is
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− | calling who.
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− | Try it and you will like it...
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− | Other digital mode decoding programs use the Hamcomm interface. You can
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− | find many of the popular programs in the 'digital decoding' section of the
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− | [[Utility Monitoring]] article. You can find decoders for WeFAX, SSTV, Packet and more.
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− | There are also a few websites listed there that have audio samples of many different modes.
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− | Trunker and programs for EDACS and other trunked systems can be found in the [[Trunked Radio Decoders]]
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− | article. I have used them and the do work. Best of all they are free.
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− | Good luck and enjoy!
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− | Mike Curtis
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