
How to Make a $19 Police Scanner - rbcoffee
https://sites.google.com/site/policescannerhowto/
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blhack
These are really fun. I have one sitting in my Jeep with me right now.

Obviously you can do a lot more with it than just listen to cops, and even
this tutorial makes it look a LOT more complicated than it is.

Plug the device in, and select a frequency. It's pretty much that easy.

I use it for listening to everything from ham radio operators to airplanes.
Seriously have had every penny worth of fun playing with this.

Here is everything you need, available on amazon prime:
[http://www.amazon.com/Receiver-RTL2832U-Compatible-
Packages-...](http://www.amazon.com/Receiver-RTL2832U-Compatible-Packages-
Guaranteed/dp/B009U7WZCA/ref=wl_it_dp_o_pC_nS_nC?ie=UTF8&colid=2RRCDXZXQJUJ7&coliid=IPEYNTUEQHOT8)

(Although I recommend a better antenna. Dig one out of your garage, that is
what I did.)

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kken
Make that a <$10 SDR:

[http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_sop=15&_n...](http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_sop=15&_nkw=rtl2832u&LH_PrefLoc=2&LH_BIN=1)

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coin
How fast can the tuner change frequencies? This will impact its ability to
scan.

Can the same USB receiver function simultaneously as the signal and control
receiver? If not then the HW cost is $19*2.

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FiloSottile
Yeah, it is said at the end of the article that the system is suboptimal
because the receiver will have to switch back and forth between signal and
control.

~~~
coin
Wonder if it's possible to use two receivers, given that are so inexpensive
($19).

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nsmalch
Now to commit the whole NATO Phonetic Alphabet to memory.
[http://en.wikipedia.org/wiki/NATO_phonetic_alphabet](http://en.wikipedia.org/wiki/NATO_phonetic_alphabet)

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jevinskie
I want to continuously monitor for 10-codes and record incidents in a DB. Any
ideas for the speech recognition portion? I figure it should be easier than
full blown text-to-speech because I'm just looking for a small set of
10-codes: 10-4, 10-55, etc.

~~~
woebtz
Google's WebSpeech API looks pretty good:
[https://www.google.com/intl/en/chrome/demos/speech.html](https://www.google.com/intl/en/chrome/demos/speech.html)

CMU Sphinx and Julius both also have options for continuous speech
recognition, but it's quite a feat to train your own [good] language model.

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jaredstenquist
Is there a Mac alternative? Otherwise i'll have to stick with my Bearcat.

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matthewmcg
GQRX works great, though you do have to dial the sample rate back a bit on
older macs (e.g. a 2007 plastic macbook)

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matthewmcg
I haven't found a native solution for trunking though.

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jevinskie
Nifty! I just got two tuners so I can listen to local analog trunk systems.
Any tips or recommendations for doing this on Linux?

~~~
pantalaimon
[http://sdr.osmocom.org/trac/wiki/rtl-
sdr](http://sdr.osmocom.org/trac/wiki/rtl-sdr) has probably everything you are
looking for, and more.

~~~
ajays
That page you linked to is a barebones guide to RTL-SDR. Any specific tips on
finding and listening to interesting frequencies (or using it as a police
scanner)?

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pantalaimon
Hm, I missed the fact that UniTrunker is required for frequency hopping, there
is OpenTrunker, but it doen't seem very active. However, there have been
reports [1] of UniTrunker running with wine.

Apart from that, you should be able to follow the directions in the OP. You
can use SDR# or more straight-forward, rtl_fm, (forget about the later, it
doesn't allow to switch frequencies without restarting, but this should be
possible with rtl_tcp) now with PulseAudio it should be possible to redirect
the audio from those applications to dsd, but that seems to expect something
like /dev/audio - I don't know how to provide that with PA.

[1] [http://forums.radioreference.com/trunking-control-channel-
de...](http://forums.radioreference.com/trunking-control-channel-
decoding/180858-unitrunker-ubuntu-10-4-wine.html)

Ok, turns out there _really_ is some additional research/instructions required
to get this running on Linux…

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makomk
Plus $25 for the software to actually use it.

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voltagex_
I remember running into this as well - there doesn't seem to be any better
software on Windows to route audio like this (AFAICR the DSD decoder software
expects a "sound card" input).

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oakwhiz
It's a shame that audio routing is pretty much nonexistent on Windows.

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voltagex_
Actually the "easiest" way around this problem would be to modify DSD to talk
directly to SDR# or the rtlsdr DLL. I'm just not sure if the Windows patches
to DSD were ever made public.

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granfular
Sure, a $19 police scanner.

As long as you have a $25 software package.

That runs on your $100+ Windows installation.

On your multi-hundred-dollar laptop.

Asshole.

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aspensmonster
And don't forget the electricity! And the rent! Clearly this headline is
misleading.

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aestra
And internet access to read this page!!

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Fundlab
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