APCO data with older scanner and discriminator tap

[jd970]

I would like to install a discriminator tap on my scanner so I can use programs like Trunker and monitor other goodies that the Motorola P25 network transmits. Do I need to install the discriminator tap on my new $500 scanner to listen to the data on the networks?

I figure a cheaper scanner would work just fine assuming it can dial in to the 700MHz and 800MHz networks, even if the scanner doesn’t have built in decoding functionality, because the computer software is decoding for me. Am I correct?

If I’m on track with not needing an expensive scanner to install a discriminator tap to listen to raw data, what cheaper scanner is pretty reliable and easy to install a discriminator tap on?

Thanks for the help!

JD

 

[fmon]

I take it you intend to use the $500 scanner for the voice scanner.

I figure a cheaper scanner would work just fine assuming it can dial in to the 700MHz and 800MHz networks, even if the scanner doesn’t have built in decoding functionality, because the computer software is decoding for me. Am I correct?

Correct.

If I’m on track with not needing an expensive scanner to install a discriminator tap to listen to raw data, what cheaper scanner is pretty reliable and easy to install a discriminator tap on?

Nearly any Uniden or Uniden built Radio Shack or any GRE built Radio Shack scanner manufactured in the 1990's and early 2000's. Many of the GRE scanners have a tap point stud ready to use and many (including Uniden) have a solder pad available. Shop on EBay, may find one for 30 bucks.

 

[SCPD]

Any scanners discrimnator tap should work fine with speeds up to 19.2k bps so apco-25 systems will not be a problem, you will need to use a four level converter to decode a 9600 APCO-25 System instead of the two level converter used for analog TRS.

 

[jd970]

4 Level converter?

So do I need the 4 level converter w/ a scanner like the Uniden BCD996?

Any scanners discrimnator tap should work fine with speeds up to 19.2k bps so apco-25 systems will not be a problem, you will need to use a four level converter to decode a 9600 APCO-25 System instead of the two level converter used for analog TRS.

 

[fmon]

>> So do I need the 4 level converter w/ a scanner like the Uniden BCD996?

Using wtrunker.exe, you don't need a slicer. The 996 will be *parked* scanner hooked to your PC at the assigned comport. The cheap scanner will be tapped with an audio cable patched to your sound card. Use Radio Shack Audio Cable 42-2420A (it's a simple 6 ft. Shielded Mono cable).

A future UniTrunker version will also work with this setup.

I use a Pro-2048 for the tapped scanner and a BC785D for*parked*. I sold a couple of Pro-2046's which could do the same.

 

[jd970]

Bearcat BC700A

Would a BearCat BC700A be sufficient for the data scanner?

 

[fmon]

Would a BearCat BC700A be sufficient for the data scanner?

Yes, if you can find pin 10 of IC-3 (see below from the late Bill Cheek). The operating manual indicates coverage from 136-174 MHz, 406-470 MHz and 806-956 MHz.

SCANNER DISCRIMINATOR CHIP PINS OF INTEREST
 Updated 11/1/96
                                 CKT     RF-in   SCAN    AUDIO
 SCANNER         NFM CHIP TYPE   SYMBOL  Pin     Pin   BASEBAND
 =============== =============== ======= =====   ===== =========
 BC-700A         NJM-3359D-A     IC-3    18      15      10