Talk:HamRadio

Saturday 17 October 2020, 20:00 UTC
After some technical difficulties with Big Blue Button, we moved to Zoom and succeeded in doing the planned agenda:


 * Brief walk-through of Simulation example: FSK


 * Presentation of gr-RTTY-basics package

https://github.com/duggabe/gr-RTTY-basics https://github.com/duggabe/gr-webserver


 * Audio loopback demo
 * Live Over-the-Air demo

The time (20:00 UTC) proved to be too late for participants East of Greenwich, so an earlier one was scheduled for 7 November.

Saturday 7 November 16:00 UTC
The meeting followed the agenda above. There was a minor audio difficulty with the loopback, but I proceeded to present the Over-the-Air demo successfully.

View the presentation on https://www.youtube.com/watch?v=_HmbRk-UG8Q

Saturday 12 December 2020 16:00 UTC
Subject: Transmit / Receive switching and station control Presenter: Gavin Jacobs VE7GSJ Agenda:
 * Requirements for TX/RX switching
 * VE7GSJ Solution (hardware & GNURadio Companion)
 * Demo on 2m repeater

Files:
 * GRC flowgraph: [[Media:Nb-fm-voice.grc]]
 * Presentation slides: [[Media:2020DEC12.pdf]]

Thanks to Gavin for an excellent talk. It can be viewed at https://www.youtube.com/watch?v=rTp6vQk5MqE

16 January 2021 16:00 UTC
Subject: Using GRC to build radios: Make the flow graph work for you

Presenter: John Petrich W7FU

Agenda:
 * Getting started with GRC
 * Basic flow graph workspace organization
 * Flow graph details
 * Data flow problem solving
 * Practical odds and ends for real radios
 * Group discussion

Files:
 * [[Media:Using_GRC_to_Build_Radios.pdf]]
 * [[Media:HF_VHF_CW_SSB_transceiver_GRC_3.7.grc]]
 * [[Media:NBFM_Transceiver_GRC_3.7.grc]]
 * [[Media:SSB-CW_receiver_DSP_-_GRC_3.8_(annotated).grc]]
 * [[Media:SSB-CW_transmitter_DSP_-_GRC_3.8_(annotated).grc]]

Thank you to John for a very informative presentation. It can be seen at https://youtu.be/j8OeK7c_zAU

27 February 2021 16:00 UTC
Subject: A Look at Project 25 (P25) Digital Radio

Presenter: Aaron Rossetto, NI

Agenda: In this presentation, I will introduce Project 25 digital radio, with a strong emphasis on its use in North American public safety trunked radio systems, and to describe experiments monitoring and decoding P25 traffic using GNU Radio code.


 * What is Project 25?
 * A brief introduction to trunked radio
 * Diving into the P25 protocol
 * Modulation
 * Packet framing and encapsulation
 * Packet types
 * GNU Radio and P25 decoding experiments

Presentation slides: [[Media:A_Look_at_Project_25_(P25)_Digital_Radio.pdf]]

Thank you to Aaron for an in-depth presentation. The video can be seen at https://youtu.be/9_Bb7g3_-7E

20 March 2021 16:00 UTC
Remember that Daylight Saving Time will have started in the U.S. Subject: Ground Station Test Transceiver

Presenter: Ray Roberge WA1CYB

Agenda:
 * What is this Ground Station Test Transceiver ?
 * Architecture – Three Sections
 * Receiver flowgraph
 * Transmitter flowgraph
 * Telemetry flowgraph
 * GUI displayed with a ADALM Pluto SDR
 * Over the Air results as received on a ETTUS B205mini on SDR-Console software
 * Discussion on finer points of Packet telemetry
 * Same flowgraph modified for UHD, Ettus B205mini and why you need to modify it
 * QT display, GRC 3.8.2 / 3.8.0 minor issues noted
 * Discussion

Files:
 * Ground Station Test Transceiver.pdf
 * [[Media:Ground_Station_Xcvr_Pluto.grc]]
 * [[Media:Ground_Station_Xcvr_Uhd.grc]]
 * These and other supporting files can be found at

Questions

 * The Ham Radio chat room on Matrix is available for follow-up and continuing discussion.
 * server: https://chat.gnuradio.org
 * or via the Homeserver in a matrix app: gnuradio.matrix.ungleich.cloud
 * room: #HamRadio:gnuradio.org


 * Questions about meetings also can be sent to "duggabe@dcsmail.net"

Suggested topics

 * Transmit hardware to operate below 50 MHz.
 * amateur radio satellite service
 * FreeDV
 * Contact ISS
 * EME - moon bounce communications
 * How to implement JS8, JS8-Call, and FT8 in GR
 * An in-depth walkthrough of GQRX
 * How ZMQ sockets work
 * Spread-spectrum