Author Topic: Hmmm FSK to USB interface  (Read 5583 times)

orion_jb2001

  • Member
  • *
  • Posts: 5
    • View Profile
Hmmm FSK to USB interface
« on: 05 Feb 2020, 02:08:28 »
Ok, just installed the interface.  Decoding pocsag 512 only.  Dip switches set to off (although the pdf manual shows all dip switches on, despite what the setting words state....)  USB drivers installed, com port selected.  Meter indicating receiving signal during scanning. 

Now the interesting bits:   PDW 3.12 options set at enable pocsag decoding 512, and that is it.   Using the discriminator, it is decoding signals, however all are showing numeric.    Hmm I thinks, using these same settings before attaching the USB interface, I was receiving alpha decodes on some of these addresses that are on the USB interface now, only showing numeric.

Fault check.  reconnected the sound card option, same options, receiving well decoded alpha text messages again on the same addresses where on the USB interface, are producing numeric scans.   ??????

orion_jb2001

  • Member
  • *
  • Posts: 5
    • View Profile
Re: Hmmm FSK to USB interface
« Reply #1 on: 05 Feb 2020, 06:14:06 »
Just as you wake up on the other side of the world, I believe I have solved the problem.  I am using a UBC780 XLT with appropriate descriminator connector and shielded cable connection.  I re did the 3.5 mm connector connections and at the same time, included the 10 k resistor, which wasn't fitted earlier.  Problem solved, there may have been a minor earth leak on the centre connector.  Working well now.

I do have another scanner, a Uniden UBC355XLT.  I tried that, then realised it hadn't had a descriminator connection set up.  Couldn't find that in the list of scanners.  Has it been done somewhere else or which unit should I look at in relation making a descrimnator output????

Discriminator

  • Administrator
  • Top Member
  • ***
  • Posts: 185
    • View Profile
Re: Hmmm FSK to USB interface
« Reply #2 on: 05 Feb 2020, 20:13:35 »
Excellent. As mentioned in my email: If you zoom in to the manual, you will see that both switches are in the off position. To avoid confusion, as a double check the text ‘off-off’ has been added.

In the original POCSAG standard, the function bit is used to determine whether a message is numerical (POCSAG-1) or alphanumerical (POCSAG-4). However, many operators don't adhere to the standard. In that case, PDW makes a best guess. In 'Options - Options', you can select to display messages both numerical and alphanumerical.

Possibly by leaving out the 10k resistor, the interface or the scanner got overloaded, resulting in the wrong decoding in PDW.

The UBC355CLT looks like your UBC355XLT.

-Rene