Wednesday, January 09, 2013

A virtual impossibility

If you have been following my attempts to set up beacon monitoring using a software defined radio (SDR) then you may remember that I had found that Omni-Rig, the radio control software used by Faros, the beacon monitoring software, would not talk to the virtual serial port created using VSPE in order to control the SDR-Radio software. I thought there was a problem with SDR-Radio's emulation of the Kenwood control protocol. In fact, that turned out not to be the case at all.

A reader asked if I had tried DDUtil, a.k.a. VSP_Manager, a program by K5FR so I got hold of a copy. The instructions made my hair stand on end as it seemed very complicated. But I managed to set up a virtual port pair between COM8, the control port that SDR-Radio was using, and COM9 which would be used by Faros. VSP_Manager threw up a few error boxes but it still seemed to have done what I asked. I then tried setting up Omni-Rig. The first attempt failed, but I decided to try again as the help files actually showed VSP Manager being used with Omni-Rig and sure enough I had Faros changing bands and frequencies of SDR-Radio.

My joy was boundless, but not for long. I fell at the next hurdle which was using a Virtual Audio Cable (VAC) to pipe the audio from SDR-Radio into Faros. VAC also looked complicated to set up, but what I was attempting to do was the simplest application of it. I created a virtual audio port and set the SDR-Radio output to use it. As soon as I connected this to Faros' input Faros began spitting out "divide by zero" message boxes so fast that I couldn't close them quick enough to get back to the Settings window to change it back again. Another brick wall.

A separate issue was that of creating a serial port splitter to allow two applications to connect to physical port COM3 used by my Elecraft K3. VSPE could do that easily, but yesterday I discovered that WSPR would not talk to the virtual port created by VSPE. However, VSP_Manager does not seem to enable you to split a real port into a pair of virtual ones anyway, so I did not pursue this avenue any further.

If you are confused trying to follow all this you are not the only one! I have abandoned the idea of using an SDR for beacon monitoring and am breathing a sigh of relief that I never decided to go down the road of buying a Flex or other software defined transceiver. SDR will never catch on until connecting the software defined radio to logging programs or digimode software becomes as simple as plugging in a real cable.


GW0KIG said...

I love my SDR 4+ receiver but like you I have experienced problems with the virtual audio cable. In my case trying to decode broadcast DRM which no matter how strong and clear the signal won't work for me. I am sure its my error but I am struggling to understand all of the settings in the VAC. As far as transceivers are concerned I will be sticking with the "knobs and dials" type of rig rather than any SDR gear. I think SDR is still a long way from "plug and play" and anyone not happy with fiddling and tweaking PC settings is likely to have problems.
The SDR receiver though comes into its own for remote operation and the ability to records directly onto your PC hard drive is also great.

73 Kevin

G4HYG said...

Hi Julian,

Don't forget that the SDR-4+ receiver has a headphone socket. If you select the internal USB Audio CODEC as the receive audio sound card in the SDR program audio will appear at the 3.5mm socket. Just connect a 3.5mm jack cable from the headphone socket to your PC mic input and you can then use Faros without having to use VAC.


Chris, G4HYG