Download glSDR free on android

Client app for connecting to Amateur Radio (Ham Radio) online servers. This version uses opengl ES 2.0 for the waterfall graphics display and may not work in some devices. Click on the menu on the bottom right corner to select the online servers.

For information of glSDR and the servers, use the About menu.

The first client that connects to a server is in master mode, and has control over the vfo and other controls so that it can tune and change bands and frequency etc. Subsequent client connections will be put in slave mode where the slave clients can only listen to the audio and watch the spectrum and waterfall in passive mode. When the master disconnects, the next slave in line will become the new master. When there are many simultaneous clients, the network bandwidth may be exceeded and some slaves will not have audio. You can see the master/slave status of your connection in the Title bar.

There is automatic Rx IQ Correction that you can enable/disable via the DSP tab.  Note that you should enable Rx IQ Correction only for servers connected to IQ based SDR hardware (eg Softrock, UHFSDR), but NOT for direct sampling hardware (eg Perseus).

It has better display for high bandwidth servers. These servers have sampling rates of 480 ksps or more thus the spectrum/waterfall displays a wide bandwidth.

Minimum of Ver 8 is needed for new versions of servers with a revamped Local Oscillator Offset mechanism.

Ver 9 has spectrum/waterfall zoom feature. Use pinch motion to zoom/unzoom. I have found it easier to put one finger in a fixed position, and then zoom/unzoom by moving the other finger.

Ver 10 has improved drag tuning taking into account the zoom factor.

Ver 11 has been tweaked for backward compatibility with Android 2.2 devices.

Ver 12 has Spectrum Averaging options and also one FMN filter at 80khz for listening to Wide Band FM Broadcasts.

Ver 13 has more Spectrum Averaging levels.

glSDR has TRANSMIT capability in voice modes, ie SSB, AM, NBFM etc. However, you need to supply the User and Password to enable transmit when connecting to a password protected server (ie ALL the public online servers). Also, it requires that your device is capable of MIC input at 8khz sampling rate. DO NOT install this version if your device is not compatible !!!

Version 25 has FILTER MENU updated swhen MODE changes. The zoom action is also magnified when unzoomed or at low zoom so that you can zoom "faster" initially.

Version 26 has been tweaked to support Adreno GPU based devices by working around some issues with 24 bit color transparent overlay surfaces in Adreno driver.

Version 27 has the waterfall initialized correctly.

Version 28 has bugfix for band specific frequency after changing from a slave connection to a master connection.

Version 29 has a customized View of the FILTER MENU to indicated the currently selected Filter.

Version 30 has a customized View of the SERVER MENU to indicated the currently selected Server.

Version 31 has an easier to understand error message when a Server is unavailable.



Version 33 has a MASTER menu button that can take over a server as the master connection, provided you have the User/Password set for the server. The User/Password is usually known only to the server owner.

Version 35 has minor bug fixes and a new MENU option for the arrow keys.

Version 36 fixes the bug when a blank Frequency is entered.

Version 38 has a MENU item for users to donate bitcoins to the project.

Version 39 has a DSP checkbox for RX DC Block. This eliminates or reduces the central spike in some radios from differential in the DC potential of the I and Q channels.

Version 40 has a "Donate Bitcoin" menu item for you to support this project. The bitcoins donated will go towards improving the number and quality of the backend servers and service quality.

Version 41 has improved stability to prevent crashes on fast rotation of screen orientation.