how to use virtual audio cable with rtl sdr

I am monitoring the NC VIPER P25 (Motorola Type II Smartzone OmniLink) system using 2 RTLs and a tapped scanner for the control channel. For VAC channels bound for DSD/DSD+, I think the most important setting is samplerate 48000hz. I'm using original VAC and I have 8 devices in play. this is the stuff that gets me fired up about radio! The upcoming Airpsy - from the author of SDR# - uses the R820T tuner as well but a vastly improved controller chip that provides 10 MHz of spectrum as well as 12 bit capability as well (should help with dynamic range and noise considerably). RTL sticks based on the R820T tuner - the majority of them - have roughly 2.4 MHz of spectrum (aka the sampling rate) available whereas the better devices (bladeRF, HackRF, USRP, etc) are capable of very wide bandwidth of 10 MHz or more. Gets complicated fast but once you do this stuff a few times, it just becomes habit pretty fast and then you're not even thinking about it anymore as it becomes easier.Īnd of course it bears repeating: this multi-VFO functionality just from one RTL stick or SDR tuner only works when the frequencies you want to monitor are all inside the visible spectrum aka the bandwidth the device is capable of. Once the source audio for each VFO is piped to a virtual audio cable, then you'd start up DSD+ and attach or assign it to use virtual audio cable 1 (by using the command line switches to do so), then fire up a second copy and assign it to virtual audio cable 2, and then finally the last DSD+ copy to virtual audio cable 3. So for example you had 3 VFOs, and 3 virtual cables - you'd assign the first VFO to output to virtual audio cable 1, then the second to 2, third to 3, etc. Click to expand.You have to use virtual audio cables to make that possible and assign the audio output of each VFO (set from their respective Audio menus) to one of the virtual audio cables.

How to use virtual audio cable with rtl sdr