VBcable receive audio problem with WSPR and Flex 1500.

4 posts / 0 new
Last post
Last seen: 4 years 3 months ago
Joined: 2011/11/28 - 02:54
VBcable receive audio problem with WSPR and Flex 1500.

Hello there everyone. I hope some of you might be able to help me with a problem I have been trying to resolve over the past few weeks in terms of trying to get VBcable software to work properly in conjunction with WSPR and my Flex 1500 transceiver. Actually; it would be interesting to know if anyone at all has successfully managed to use VBcable software with any Flex radio instead of the recommended VAC 4.xx programs.

Although I still have not had any luck getting things working with the VBcable (virtual audio cable) software, it appears that everything does work if I change the audio routing parameters both in WSPR and the Flex 1500 to utilize my computer's on-board sound card in conjunction with the analog audio I/O jacks to which a microphone and headphones are connected. The RX gain and TX gain audio sliders within PSDR work perfectly then allowing for proper transmission and reception adjustments.

The computer I initially used was a 12 year old Toshiba 17 inch desktop replacement laptop; a Satellite P25-s607 with an Intel Pentium single core 2.8Ghz hyper-threading socket 478 cpu, 2Gb of ram and an Nvidia GeForce FX Go5200 64MB video subsystem, all running on a Windows XP MCE operating system. Surprisingly; it runs the Flex 1500 fairly well; albeit with relatively high cpu utilization of about 60% to 80% in full screen mode. Mind you; if I reduce the screen size of PSDR and simultaneously run WSPR, the utilization drops to about 40%. The screen size of PSDR definitely has a large effect on the cpu utilization of my old computer with its limited video subsystem. I also tried using a more current Intel I-5 based processor with Windows 7 home premium 64 bit and got the same results.

Unfortunately; trying to get audio to move digitally inside the computer with VBcable software was only partially successful. I managed to install both VBcable A and VBcable B programs; unzipped and installed them on my computer and configured them properly for inputs and outputs both in the Flex 1500 VAC1 setup window as well as in the WSPR 2.0 (r1714) station parameters window.

The receive level in the bottom left corner of the WSPR program window varied randomly and did not indicate any decoded data or horizontal lines in the receive window even when the level was within acceptable limits at times. There was also no control over the receive level when attempting to manipulate the VAC1 RXGain slider in Power SDR while in DIGU mode. The only effect I could impose on the received audio gain as seen on the WSPR program window was when I turned the preamp off (0dB) in PowerSDR which caused a receive audio reading of -30dB(effectively no audio). If I switched the preamp back on to +30dB in PowerSDR then the WSPR receive reading jumped back upwards to some random nominal level. On the other hand, there is no problem at all adjusting the VAC1TXGain slider and seeing a corresponding rise or fall in ALC levels and transmitter power output.

The problem appears to be only with the VAC1 RXGain having no effect on the received audio from the Flex to the WSPR program. Am scratching my head about this. I would certainly welcome any suggestions as to what might fix this problem.

The response from Flex Radio (after opening a support request) was that they have no experience with VBcable software and recommend use of VAC4.xx programs.

Regards: John VE3INH

P.S. : One other item that is both a source of confusion and frustration is not seeing or being able to adjust the input and output bit rate and sampling rate of audio in WSPR 2.0 in its setup screen. Would anyone know what those specifications might be?