A really stupid question...

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ETMegabyte

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I have a really stupid question, which someone may be able to answer...

I have a digital scanner, and I love it. I'd love to set up a feed for radioreference, but sometimes I take the scanner with me, so that's not really an option... However, I had another thought...

A digital scanner, once you remove all the superfluous features, is basically no different than the older scanners with the exception that it can decode digital signals and turn them into usable sounds. My question is why can't a computer do the same thing?

Think about it for a minute. With the exception of Trunking systems, P25, and EDACS, most signals still in use today are no different than they were 15 years ago, in that most police and fire departments still broadcast on a single frequency. The exception is that the old scanners now only "hear" a vacuum cleaner when someone's talking... Why can't a computer take that "vacuum cleaner" sound and translate that to something useful? I'm thinking something like my old bearcat scanner, hooking it up to the audio input of my computer, and having a piece of software listen to it. When it "hears" something, it translates it to a usable sound and outputs it to the speakers...

Isn't this basically what the newer scanners do now?

A piece of software like this could make all of those old scanners sitting on the shelf useful again!

Is this possible? Has anyone done it? Anyone wanna give it a shot? Interested in thoughts...

-ET
 

poltergeisty

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:lol:

I remember having this question several years ago too . :wink:

Might put the industry out of business, no? :lol:

ETMegabyt, read about pocsag, WEFAX, ACARS and other data formats.


Virtual KVL's are what's up my alley... I'm sure it's been thought of before, like GPS SAME. :lol:
 
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ETMegabyte

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I read the wiki page, and I think I'm more confused than when I started... I apologize for seeming n00b-ish, but in this case, I really am a n00b...

In the 6+ months I've been using my new scanner, it's become clear that none of the stations that I listen to regularly are trunked in any way, so a standard (analog) scanner would be able to scan the stations properly. In fact, standard analog scanners (like the Pro-2028 that I've had on my desk for-like-ever, and the Pro-2046 that's been in my plow truck for as long as I can remember!) would work just fine, except that when the stations I listen to transmit, I hear a vacuum cleaner...

The wiki implies that I could put a discriminator tap onto one of my old scanners (which is one hurdle - since I'm HORRIBLE with a soldering iron - hands shake slightly all the time making clean solder joints almost impossible), but other than that, it seems that once this tap is in place, I can pipe it into the mic-in (or line-in) on my sound card of a linux-based machine, somehow run this software, and it will translate the vacuum-cleaner like noise to the same voices I get from my Pro-106?

I'm pretty interested in getting this idea flying. Neither of the areas I listen to regularly are broadcast on RadioReference.com (or anywhere else that I can find, for that matter). If I can get this going, I have every intention of using 1 (or 2) of my analog scanners to broadcast those streams to RR... I have a pretty hefty business-class internet connection here, with 5 static IPs, all of which is connected to UPSs, so even if the power is out, my internet typically still stays up... I have everything needed (and then some) to broadcast a scanner feed except for a dedicated scanner... Sadly, I'm disabled, and on a fixed income, so the purchase of a dedicated $400+ scanner just to broadcast over the internet is out of my financial ability... But if I could get one of my (many) older scanners working with this, then I'd have no problem broadcasting..

Has anyone actually DONE what I'm trying to do, and can they tell me if it actually works? I'd hate to go through a bunch of work (and possibly ruin a scanner trying to put in the tap) just to find it won't do what I want it to...
 
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n5usr

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Yes, I've done that. (Up to the decoding part, never fed a stream with it.) In my case, it was a trunked system so was impossible to really follow the conversation. If yours are just single-channel digital signals then no problem.

As long as the digital mode they are using is one that can be cleanly decoded by the DSD software, you shouldn't have any trouble with the audio. It's been a while since I last tried, but I was trying to listen to EDACS ProVoice with my setup and the audio was VERY glitchy at the time. Would have been unpleasant to listen to, but then even that might be better than nothing at all...

Discriminator taps can be easy or hard, depending on the scanner. The handhelds are, of course, quite cramped and sometimes require removing various delicate bits to get to some buried PCB. But I was pleasantly surprised when putting a tap into my PRO-2052 just how simple it was. The PCB was larger / more spread out, and the connection point was very easy to reach, with (comparably) ample room around it. Also tons of space inside the case to place a jack on the back panel to connect an audio cable. Just depends what radios you have.

Continuing on to the feed portion, you should also be able to supply the feed straight from the same box that decodes the audio. I use Linux on all my servers, and use Darkice to supply my feed.
 
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ramboton

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I was thinking the same thing, I have several old scanners, and do not want to spend $600 to replace the two scanners that I provide my feeds with just to get digital. (the Local Sheriff's dept is digital capable but usually transmits analog.) I wanted to do a discriminator tap, and try the software conversion, my thought is how does Darkice know to grab the audio at the input or after DSD has converted it?
 

vinzep491

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May I ask a question - I understand the basic concept of DSD, but what is a discriminatior tap??
 

vinzep491

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I understand a google search would help me, but I value the detailed explinations of my fellow scanners over an unknown web author.
 

ETMegabyte

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I understand a google search would help me, but I value the detailed explinations of my fellow scanners over an unknown web author.
A discriminator tap is basically a connector that allows you to get the raw data that the scanner receives BEFORE it's put through the scanner's audio subsystem. This is required for DSD because the audio subsystem/amplifier inside of your scanner tries to "clean up" the input signal before amplifying it and sending it out to either the speaker or your headphones jack, which in turn messes up the digital signal.
 

swstow

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if i may add a question or two to the mix, i to do not understand discriminatior tap that much eather, i was under the impression that some of the newer radios ( last year or two of production ) were coming with discriminatior tap already installed and my orther question i will bemoving back home to daytona beach in the next few months and i know they are going pro voice next year, if im understand correctly a discriminatior tap will be needed but how with can one get it to work in a moble unit, will a lap top be needed in the vehical to decoding ( thinking about that anyway )
 

poltergeisty

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I'm not sure about having a baseband audio tap for Pro Voice, but if the tap is required, then yes you will need to use you laptop. You could buy a netbook, but then again the netbook would need an express card slot to support a serial adapter. Something like this:RS-232 Serial Port to Express Card ExpressCard Adapter | eBay

That is if you need a serial connection. You may not. Perhaps only audio input would suffice.
 
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