Slicer pass through wiring for single com port

[2WAYMAN]

5-8-12 0048 HOURS EDT
Hello all........hopefully this is the correct forum for this inquiry.
Am designing/fabricating a couple of new data slicers for use with Unitrunker and E-Unitrunker and need a confirmation about some wiring.
In the past I have made the slicers with an extra DB9 connector for connection of a second (voice ) scanner attached when you have only one com port on a computer, such as many laptops.
Would like to confirm that the only wires which need to go from the comportDB9 connector on the input side of the slicer through to the other DB9 connector should be to pins 2, 3 and 5(ground)--- is this the correct configuration?
Thanks in advance for all assistance!
73;s!

 

[wa8pyr]

5-8-12 0048 HOURS EDT
Hello all........hopefully this is the correct forum for this inquiry.
Am designing/fabricating a couple of new data slicers for use with Unitrunker and E-Unitrunker and need a confirmation about some wiring.
In the past I have made the slicers with an extra DB9 connector for connection of a second (voice ) scanner attached when you have only one com port on a computer, such as many laptops.
Would like to confirm that the only wires which need to go from the comportDB9 connector on the input side of the slicer through to the other DB9 connector should be to pins 2, 3 and 5(ground)--- is this the correct configuration?
Thanks in advance for all assistance!
73;s!

It's been awhile since I built a slicer to do the same and I don't recall the pinouts off the top of my head, but all you need is TxD, RxD and Gnd, so that sounds right.

If it doesn't work the first time you may have to wire it as a null modem (TxD to RxD, RxD to TxD, Gnd to Gnd).

 

[pro92b]

This works for me.

 

[SCPD]

Am designing/fabricating a couple of new data slicers for use with Unitrunker and E-Unitrunker and need.

You must mean Trunker and Etrunker. Unitrunker doesn't support traditional slicers.

 

[2WAYMAN]

Slicer pass through

5-10-12 2359 HOURS EDT
Thanks wa8pyr, pro92b and Unitrunker for that info. Unitrunker, when you say that the Unitrunker software does not work with traditional slicers, do you mean that it only works with one of our newer scanners with control channel output such as the Uniden BC396XT or BC996XT? If so, why would a tradtional slicer not allow control channel decoding as is done with Trunker?
73's !

 

[SCPD]

Unitrunker, when you say that the Unitrunker software does not work with traditional slicers, do you mean that it only works with one of our newer scanners with control channel output such as the Uniden BC396XT or BC996XT?

The program works with "Inline" decoding receivers like the models you describe. It also accepts discriminator audio through your computer's microphone or line input.

If so, why would a tradtional slicer not allow control channel decoding as is done with Trunker?
73's !

The slicer toggles the modem status pins. It does not use the TxD and RxD pins. In DOS and Windows 98 you have direct access to the hardware allowing the software to make accurate timing measurements of pulse widths to determine 1s and 0s. This scheme is limited to simple two level and four level waveforms. C4FM waveforms can't be decoded this way. Also, on Windows NT, 2K, XP and later - the OS does not allow direct access (is possible to bypass but requires special drivers with varying degrees of compatibility). Timing measurements are not as reliable because Windows can suspend the program while it is making a critical measurement.

Some additional information.

UniTrunker | Time Slicer

Decoding from sound input is much more flexible.

 

[2WAYMAN]

Slicer pass through

5-11-12 11 PM EDT
Thanks Unitrunker for that really good, detailed explanation. On the BC780XLT there are two slicer tap points on the board, as this unit as well as the BC796D also has, which some RR users have shown can be brought right to the DB9 port at the rear of these radios connecting same to pin 8 as CTS. Since these
units contain 'internal control channel decoders', can THEY also be used with Unitrunker providing one makes the above mod to the serial port at the rear of the scanner???
Thanks once again for all of your really good information!!
73's

 

[SCPD]

The mod you describe uses the CTS pin which is one of the modem status pins (DSR, CTS, DCD).

To use these radios with Unitrunker, connect the unmodified DB9 to the computer. Add wiring to bring discriminator audio outside the radio. A 1/8th patch cable connects radio to computer sound input.

 

[2WAYMAN]

Slicer pass through connectons

5-13-12 0048 HOURS EDT
Thanks again Unitrunker. I wired a normal discriminator tap for the BC780 XLT brought out the back of the radio with an inline .1uF capacitor to a 1/8" mono jack, as the only connections are the center conductor and ground. The line in jack on a sound card is usually a 1/8" stereo jack You stated to use a 1/8" patch cord from the tap jack to the line in jack of the computer soundcard, and connect the serial port of the computer to the serial port at the rear of the scanner. Don't you need a 1/8" stereo to mono jack adapter
for the computer end of the mono patch cord??
Thanks in advance!
73's !

 

[SCPD]

Don't you need a 1/8" stereo to mono jack adapter
for the computer end of the mono patch cord??

I use a mono to stereo adapter when two receivers share one audio input. I don't have a problem plugging a mono cable into my laptop's stereo input. Your mileage may vary.

 

[pro92b]

5-13-12 0048 HOURS EDT
I wired a normal discriminator tap for the BC780 XLT brought out the back of the radio with an inline .1uF capacitor to a 1/8" mono jack...

Is the normal tap point LND08? If so, that's not the best spot because its has restricted high frequency bandwidth and may need to have DATA SKIP turned on for it to be active.

Your sound card may have an input impedance around 10K Ohms, at least my ThinkPad does. Then the capacitor should be much larger than 0.1uF and most people settle on 10uF.

A better tap point is IC11 pin 14 because it is always active and it has wide enough bandwidth to reduce phase shift in the signal band (below 5 kHz).

 

[2WAYMAN]

Slicer pass through connectons

5-13-12 3 PM EDT
Hi Unitrunker and thanks for the reply. I will use a mono to stereo adapter plug on the computer sound card end of the patch cord from the discriminator output of the scanner just to be on the safe side, and not wire up either of the two slicer points on the BC780XLT's as it appears you only need to connect to the sound card line input jack. I know that you need to connect the radio via the DB9 serial port so as to be able to use the remote feature and to program the unit.
Thanks again for your kind support!
73's !

 

[2WAYMAN]

Slicer pass through connectons

5-13-12 3:15 PM EDT
Hi PRO92B.......Just read your post about the discriminator tap point on the BC780XLT. That LND8 Data Skip is where most people seem to connect to, but I see your point. I see you have marked in red the 10uF cap and also a 1K resistor???? Now will this setup also work when I use my old DOS computer with TRUNKER as well???
Thanks!
73's!

 

[pro92b]

5-13-12 3:15 PM EDT
Hi PRO92B.......Just read your post about the discriminator tap point on the BC780XLT. That LND8 Data Skip is where most people seem to connect to, but I see your point. I see you have marked in red the 10uF cap and also a 1K resistor???? Now will this setup also work when I use my old DOS computer with TRUNKER as well???
Thanks!
73's!

The 1K resistor provides a bit of isolation between external connections and IC11. It's not critical but falls under the category of good engineering practice. This tap circuit will properly feed a data slicer or sound card.

 

[2WAYMAN]

Slicer pass through connections

5-13-12 2215 HOURS EDT
PRO92B ......
Just took apart one of the BC780XLT's and searched for IC11- could hardly see the 14 pins without a magnifying glass. The IC has these markings: 3403A, 1015D, JRC . Is there a spot where this infamous "pin 14" is accessible from the green non-component side of the board? It looks like it would be almost impossible to solder to the actual IC without possibly damaging it from the heat or accidentally cross soldering it to the next pin even with my Weller ESD soldering station.
I'm thinking I might have to leave the tap spot on LND8 but put the larger cap and 1K resistor inline as you suggested.
Suggestions re: IC11?????
73's !

 

[pro92b]

5-13-12 2215 HOURS EDT
PRO92B ......
Just took apart one of the BC780XLT's and searched for IC11- could hardly see the 14 pins without a magnifying glass. The IC has these markings: 3403A, 1015D, JRC . Is there a spot where this infamous "pin 14" is accessible from the green non-component side of the board? It looks like it would be almost impossible to solder to the actual IC without possibly damaging it from the heat or accidentally cross soldering it to the next pin even with my Weller ESD soldering station.
I'm thinking I might have to leave the tap spot on LND8 but put the larger cap and 1K resistor inline as you suggested.
Suggestions re: IC11?????
73's !

I sold my BC780 years ago and can't trace the circuit further without having the radio in front of me. Go ahead and use the 1K and 10uF on LND8. If the performance falls short of your needs we can revisit the IC11 connection.

 

[2WAYMAN]

Slicer pass through connections

5-13-1`2 2245 HOURS EDT
Hi pro92B........Thanks again for the reply. I will give you an "e-shout" when I get a chance to pick up that stereo to mono adapter along with a 1 K resistor and install it along with the 10uF cap. Then I'll run it up on Unitrunker and see what show up.
73's !

 

[2WAYMAN]

Slicer pass through connections

5-17-12 0036 HOURS EDT
Hi pro92b............
Well, tried to use Unitrunker with the discriminator tap modification (resistor and cap) with no luck at all. I must be missing something so all assistance is welcomed.
I connected the 1/8" mono plug into the discrim. tap 1/8" mono jack on rear of the BC780XLT. The other end went to the mic input of my laptop. Also connected the serial cable to the rear of the scanner and the other end to the computer serial port. Set the baud rate of both at 9600. Even tried a mono to stereo adapter on the cable at the laptop end.
Put the scanner in non-trunk mode and on manual on the control channel for the trunking system.
Non receiving anything, in fact the screen for viewing the system info, talkgroups and freqs. does not even appear at all!
So, what did I miss and or what do I need to do to make this thing work!
Thanks for the assist!
73's !

 

[Comint]

5-17-12 0036 HOURS EDT
Hi pro92b............
Well, tried to use Unitrunker with the discriminator tap modification (resistor and cap) with no luck at all. I must be missing something so all assistance is welcomed.
I connected the 1/8" mono plug into the discrim. tap 1/8" mono jack on rear of the BC780XLT. The other end went to the mic input of my laptop. Also connected the serial cable to the rear of the scanner and the other end to the computer serial port. Set the baud rate of both at 9600. Even tried a mono to stereo adapter on the cable at the laptop end.
Put the scanner in non-trunk mode and on manual on the control channel for the trunking system.
Non receiving anything, in fact the screen for viewing the system info, talkgroups and freqs. does not even appear at all!
So, what did I miss and or what do I need to do to make this thing work!
Thanks for the assist!
73's !

Do you hear the Control Channel through the scanner speakers. If so, plug an earphone into the Discriminator Tap socket, and see if you can hear the audio there. If there is no audio there, then UniTrunker has nothing to display.

--
Comint

 

[pro92b]

Turn data skip on, use the audio control panel in the computer to try to monitor the audio from the tap, try inverting polarity (the program may auto-detect polarity, not sure). This tap should work with DOS Trunker and you can try that too. Conecting an earphone to the tap may not yield anything because the load may be too great. A program called Slicer can be used to test the tap signal. Get it at Index of /~phoenix/wap