• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
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Just alittle pissed off

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Sjinndoawi

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I did the discriminator tap on my BCD996T and I am trying to run unitrunker and its not happening..I push F1 and I see no signal so I go to (R)eceivers to set it and it wont accept BCD996T IT KEEPS GOING TO UBCD996t OR when I hit (s)ave it just picks some other receiver. I now goto tuner and I will not let me pick a PORT it only gives me COM3. Whats up with that.?

Here is something I still see **no signal** but it is listing this
Type Sys ID Lable
Motorola 1F25
Motorola 3619
Motorola 813A

and this I hit Pr(o)ps and see this

Key Value
type MPT1327
Profile 0.17
Ignore 0
Sync 00000000
but it still is saying **no signal** up on the top..
Did I do the discriminator tap wrong? I am using cat 5 shielded cable 10uF cap with a 10k resistor a 3.5mm mono jack with a mono 3.5mm cable and grounded the jack to a screw on the board. Am I using this program wrong(more then likely.. I am using Unitrunker 0.1.0.57..

Any hepl would be great cus I am sooooooooooooo lost here


Brian
 

KE5MC

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I am not familiar with the tap circuit details, but 10uF sounds a little big for small signal coupling. Is that the value recommended in the modification description? If it is then possibly the cap is in backwards. 10uF would be electrolytic or tantalum both polarized. Caps are also easy to misread, I have done it several times.

mike
 

Sjinndoawi

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Something is not right... I don't get anything on the uniscope. No movement just a flat line.. I checked the 10uF cap and the plus side is solder to the discriminator point..So I dont know what I did wrong...I even cliped out the 10uF cap and put the coax cable on the tap point and still got nothing on the uniscope....


Brian
 

Airdorn

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Plug it into your mic input on your sound card.

Open your sound volume program in Windows, select Options, and change to Recorder input. Turn on mic boost. Work the slider up and down while Uniscope is running and see if you get some activity.

I, too, have a BCD996T and did the discriminator tap. If all else fails, you can simply conenct straight from the tap to the soundcard. Some nay-sayers preach against it, but in reality it seems to work in a pinch. I once ran a tapped scanner for years straight to a Windows 98 computer with no ill effects.

The whole name of the game here is to manage your hardware to get the levels right. You are connecting a somewhat unorthodox audio source (tapped 996T) to your computer through the soundcard via the mic input, and so you have to use all that is available to get everything at the right levels. In most cases, everything pretty much just falls into place, but I've noticed that in some cases some tweaking around with Windows settings are needed.

Uniscope is your friend. That's one little program that runs on my desktop at ALL TIMES. It lets you see the discriminator output, as it looks at your soundcard's mic input. If you don't see anything and you are sure your discriminator is working properly, then you either have mic boost off and your levels are low, or something else is wrong with your Windows installation.
 

Sjinndoawi

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I cant get it to work..I even went as far as too take the resistor off as well as the 10uF cap and just run the cat 5 cable from the tap to the 3.5mm mono jack then run the uniscope program and got nothing... Did the mic boost and ran record for the sound card and nothing at all just a flat line...this SUCKS

Brian
 

Airdorn

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Well if you plug a regular PC mic into your soundcard's mic input, does it work? Maybe you have a crappy or bugged sound card.

And its gotta be the mic input.. not the line-in.

I guess the main things that you have to know are:

1. Your PC's soundcard, mic input, etc. do, in fact, work

2. Your discriminator MOD really does actually output the disc audio.

You can test #1 by using a PC mic and uniscope and seeing if talking into the mic makes uniscope react. If it does, then your soundcard is configured correctly and the problem has to be the disc tap. If it doesn't, you have to screw-around with Windows until you get your sound working right.

You can test #2 by maybe connecting your new disc tap audio to a stereo line-in and seeing if you get audio there. If you do, then your disc tap works ok and you need to play with Windows and your soundcard. If you don't get audio, then you need to check your tap.
 

iamfunk

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taking another step back...if you un-mute whatever input you are using... do you at least hear what sounds like static, or digital sounds from your computer speakers?
 

mancow

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Did you make sure you have a good ground?

Try replacing the cap with a .1 uF 10 is just too big.
 

slicerwizard

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mancow said:
Try replacing the cap with a .1 uF 10 is just too big.
No, it's not. All of my taps (4 so far) use 10 uF tantalums plus 10k isolation and they all provide clean signals from 300 bps through 9600 bps. If the OP ever wants to decode low speed data (like LTR), he'll want good low frequency response, and he won't get it from a 0.1 uF cap.
 
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