Using GM300 to decode Pocsag? can it be done?

[Essexsaxo]

Hi all,

I'm new to the group, I've had a crack at decoding some pocsag data using the discriminator from the rear connector and my PC running PDW pocsag decoder and the audio seems a bit load and over modulated. I've been transmitting Pocsag with this radio and it works wonders. Has anybody had any results with using these radios to decode?

Nick

[ve3nsv]

Are you using Pin 7 and Pin 11 for the receive audio with the internal jumper set to DISC? Can you just not turn the LINE IN level down in the Recording Tab of the Volume Properties?

I have used a CDM1250 and CDM1550 for both Trunker and PDW and have had no issues at all. The computer I use has a Crystal Audio chipset.

[Essexsaxo]

Hi,

Yeah i'm using pins 7 and 11, do you know which jumper is for the discrim? I've tried playing with the audio with the computer settings and it still doesn't seem right compared to my scanner.

Nick

[motorola_otaku]

JU551 on the command board. Position A is unmuted/flat (discriminator) and position B is muted/de-emphasized. Muted/de-emphasized is what you want if the audio you have now is too "loud", but I don't know how much the de-emphasis process might affect your decoding.

[Essexsaxo]

Hi,

Thanks for your help, I've added a 10k resistor in line on the data output and it seems to work a bit better, I may have to try different values. The GM300 is absolutly brilliant for sending Pocsag messages.

Nick

[Will]

Nick you may need a DC de-coupling capacitor as well as the 10K resistor.
There is DC on the DISC and Filtered audio output from the OPamp.

[Essexsaxo]

Thanks will, i'll give it a try