OP25 project : two announcements

While all of this has been mentioned previously on our op25-dev list,
I’d like to take this opportunity (from the GR 2011 Conference in
Philadelphia, Penna.) to announce a couple of sub-projects which could
be put off forever (nothing is ever truly “finished” :wink: but nonetheless
would benefit from wider examination and comment, especially at this

First is our integration with Asterisk (VOIP), specifically their
app_rpt project to provide a rich set of repeater semantics (to include
NBFM with CTCSS and P25). Targeted features working today are:

  • Simultaneous multi-channel transmission/reception
  • Uses USRP and/or conventional receiver/transmitter hardware
  • Generic interface to Asterisk via app_rpt (full VOIP, radio
    control, and standard repeater functions)
  • Features: P25, analog NBFM with CTCSS
  • Expected to be fully “ROIP” [Radio Over IP] compatible For details
    on the repeater stuff please visit

Second is an enhanced version of our signal visualization and analysis
app which features:

  • Spectrum plot

  • Baseband oscilloscope

  • Eye Pattern Diagram (Datascope) display supporting several
    standard symbol rates

  • Constellation Diagrams

  • Demodulated Symbol Output

  • Correlation (including Fast Auto-Correlation)

  • Direct-frequency entry, signal gain and fine-tuning controls

  • User-selectable demodulator (FSK4 or QPSK) A goal for the app is to
    accommodate a range of targets:

  • Choice of USRP, discriminator-tap, or “audio-IF” hardware modes

  • Supports either GL or non-GL display mode

  • Lower and middle range PC hardware, not just the latestThe link to
    the project page is

Best Regards


HI Max

When we go to the follwoing link:

We get a login/password page for the university.
Is there a way to see this content without a unversity login?

Thanks in Advance

Bob Brown