Help needed with data slicer

[troymail]

I'm looking for some input on troubleshooting a new data slicer
that I built and it's use with trunker.

First - I built a data slicer according to:
http://www.bookshock.com/articles/slicer/intro.html

I believe I followed everything as listed with two exceptions:
I was given an NTE778A in place of the MC4558
I used a DB-9 instead of a DB-25.

I've confirmed a tap (assume it is good) from my BC-245 (I
have audio from my tap lines out of the scanner)

I connected everything up and tried using slicer.exe to
test the setup. However, I'm getting nothing. I've tried
different ports and computers from DOS5.0 on a Dell 266,
to Win2K on an old PC, to WinXP on a Celeron machine.
None of them seem to see anything from the slicer.

Other than the obvious that my data slicer build was bad
or one of the components are bad, any other ideas?

I've read on the slicer.exe doc page that some serial ports
are using 5v verses 12v which could be a problem... can
someone point out how to check that?

Any help would be appreciated.

Thanks

 

[SCPD]

Just do some basic troubleshooting.

Get a multi-meter and start probing.

Use the ohm-meter to check continuity in the wiring - particularly the DB9 cable.

With the unit plugged in and runing, check the voltages on the pins to the DB9. Make sure they are what you're expecting. Check the power pins into the IC ... and so on.

-rick

 

[JamesO]

Could it be that you need to flip the wires to pin 2&3 on the D9 connector?

Many folks do not realize that pins 2&3 are flipped between the D9 and D25 config!

JamesO

 

[troymail]

At this point, based on the instructions for the DB-25,
I am only using DB-9 pins 4, 5, 7, & 8

 

[SCPD]

Yep - slicers - both 2 and 4 level designs don't use the TxD/RxD pins. That's why you can sometimes get away with controlling a second scanner on the same serial port as the slicer.

-rick

 

[JamesO]

RF Mobile,

This makes some since, as I have seen the pass through D9 interfaces on some data slicers!

I am slowly getting interested in playing the data slicer game to see what I might be missing.

Is there any real advantage with the 4 level data slicers? What vesion data slicer do you recommend?

JamesO

 

[SCPD]

The 2 level slicers are very easy to build. Just one IC and a few discrete components.

The four level slicers are about two or three times the difficulty - I'd suggest starting with the 2 level circuit. The 2 level slicer will decode most of the common trunking protocols like Motorola, EDACS, MPT1327 and LTR.

Some signals can't be decoded with a 2 level slicer. APCO P25 is one example.

Bill (pro92b) has a few well thought out web pages on the subject.

http://home.hvc.rr.com/bpetrow/

-rick

 

[JamesO]

Thanks for the insight on the data slicers. Now to find the time to play with them!

JamesO

 

[fmon]

Some signals can't be decoded with a 2 level slicer. APCO P25 is one example.

http://home.hvc.rr.com/bpetrow/

-rick

Rick, I was going to contest your quote, because I use a level 2 and have run Trunker on Chesapeake VA successfully. I assumed it was since it’s listed as APCO P25 on TRS and other sources. So before stepping on it, I checked my 7a32C1.txt for Chesapeake and found: DESCR=Type II Astro NetWkd 116.3 Hz. I guess it's time to make corrections to some databases.

Thanks for the tip.

 

[SCPD]

Hi fmon;

You don't know how many times I've saved myself from online embarrassment by checking a few facts beforehand (and not that I get it right 100% of the time either).

A couple of tip-offs that you've got an Astro system are: (1) you can use Trunker to monitor it and (2) the system id is a four hexadecimal digits long.

9600 baud P25 systems have a three digit hexadecimal system id.

-rick

 

[troymail]

Shazam!!!!

I finally got my slicer working (re:
http://www.bookshock.com/articles/slicer/intro.html) ... the
instructions had several errors ---

(1) the 100k resistor is correct but the color bands to check for
are listed incorrectly they should be BROWN-BLACK-YELLOW
(I caught that one early)

(2) step 7: "A1" should be "B1"

(3) step 9: "B1" should be "A1"

(4) step 9: "A8" should be "C7"

Following that -- it came right up!!!!

Thanks to everyone who provided help....

 

[fmon]

Great!!

After playing with trunker, you'll need to submit corrections to Bookshock.

 

[uhfmtr]

Level-4 FSK Slicer

I've been looking for a level 4 fsk slicer. Does anyone hve a supplier that currently has one in stock?

Thanks
UHFMTR

 

[crayon]

I've been looking for a level 4 fsk slicer. Does anyone hve a supplier that currently has one in stock?

There are some to be bought out there, but the market is not that strong for this type of product.

If you are adept enough .. you would be best served if you rolled your own. pro92b has done extensive research (almost emperical in nature )in this area and documented the findings for everyone to use.

His website can be found here: http://home.hvc.rr.com/bpetrow

 

[BANDIT]

Try www.texas2way.com

 

[letarotor]

Texas-No-Way.not

Bandit,

Texas-2-Way must be out of business. Their web site is no longer, phone is disconnected and earlier this year they would not respond to repeated e-mails. Not surprising, however, their customer service was terrible even when they were in business!

If anyone knows of another source for 4-level boxes please post.

Mark

 

[morfis]

Bandit,

If anyone knows of another source for 4-level boxes please post.

Mark

In The Netherlands rather than the US but Rene is the person to talk to:

http://www.discriminator.nl/4-level/index-en.html

 

[morfis]

Bill (pro92b) has a few well thought out web pages on the subject.

http://home.hvc.rr.com/bpetrow/

-rick

This yields an empty page here using mozilla and also internet exploder - is the site dead?

 

[crayon]

This yields an empty page here using mozilla and also internet exploder - is the site dead?

pro92b decided not to keep the site up and running. You can check out an archived copy at:

http://web.archive.org/web/*/http://home.hvc.rr.com/bpetrow/

Hope that helps ...