More than one interface on a single PC

[Discriminator]

Can all the USB interfaces run through a 4 port USB hub into a single USB port, and the 4 instances of PDW run on the same PC (XP SP3 likely, but could go to W7)?

I haven't tried a USB hub. Please keep me posted on your results.

[VidarParry]

I've been testing using the earphone socket of my scanner instead of a dedicated discriminator tap so the audio probably isn't the best of quality. I am going to hook up my interface to my Motorola GM radio that has a Discriminator output on the rear plug and see what happens. I'll keep you posted. My new laptop just will not decode pocsag via the soundcard, I've spent hours tinkering with the audio levels and it just won't do it, my sold laptop worked faultlessly at decoding.

In my experience, discriminator tap will always give a better result with PDW than soundcard - although I've never achieved "perfect" POCSAG decoding on either.....yet! Hopefully, the new interfaces will bring me closer to the perfect decoder:-)

Cheers
...Steve

[Torquetube]

Have you received your new interfaces yet Steve? I'm hoping to test out my Motorola Pmr radio later to see if it will work for Pocsag decoding.

[VidarParry]

Hi Rene,
No - not arrived yet. Did the package have a tracking number? If so, please email me it off list.
Cheers
..Steve

[VidarParry]

WOW!!!

The RS232/USB interfaces arrived earlier this week. Couldn't wait till the weekend to play, so after an initial test to make sure they worked (which they did of course!), I constructed a power arrangement using an old Notebook 12v PSU feeding six power cords (4 for the interfaces and 2 for the scanners). Then connected up the 4 USB connections into a cheap ($4 on ebay) 4 port USB hub into my old IBM Pentium PC running XP SP3.

Rene had earlier suggested that the discriminator tap resistor should be reduced to facilitate 2 outputs per scanner (remember I'm monitoring two frequencies each with 512 and 1200 messages). I went for the easy option and made two discriminator leads that went from one tap to two outputs - in parallel. No impedance matching or protection.

I then plugged in the scanners to the interfaces, ran up 4 instances of PDW, configured them to match the ports, and hey presto - 100% decoding straight away!

They've now had a full 24 hours operation and just going on logfile sizes they are decoding about 25-30% more than my previous 2-level slicer configuration (adding the new 512 and 1200 logfiles together and compare with the previous combined log sizes).

Two small problems I'm working on:

• On startup (all 4 PDW's are started from the start folder on boot), the 3rd or 4th PDW says Comms port not found. I'm sure this is a timing issue so I'm dabbling with batch files to address this.
• The four interfaces don't have cases. Temporarily I've put them in antistatic sleeves, but need to find a more permanent solution. Rene suggested plastic soap boxes.

For the first time in nearly 18 years of decoding, I'm pretty confident that this is now picking up 100% of messages, where I knew that the 2-level slicer was missing loads (just by hearing the message on the scanner and seeing PDW -not- detecting it.)

I highly recommend the RS232/USB interface for serious decoding - well worth the money, and it helps Rene support this great site as well as a little thank you to Peter Hunt.

Thanks for all your help and advice Rene:-)

Cheers
...Happy Steve

[Discriminator]

Excellent! Thank you for your comprehensive report. I'm happy too 

-Rene

[Torquetube]

I'm also pleased to say that I have got my RS232 interface working nicely now, I didn't realise that my Alinco DJ-X11 scanner already had a discriminator feature built in so I have made a lead and just tried it and it's working. I too would highly recommend the interface. I just need to find a nice case to put it in now.