[hpsdr] Audio output noise

[Mike F]

I am still struggling with the problem described below.  I have tried 
several suggestions without any positive results.  I have the following 
additional information about the problem.

I set up VAC to send the signal to the PC Speakers.  The PC output goes 
away when in transmit and when PSDR gain is at zero, as it should. (mute 
doesn't affect the VAC process).  The noise is not in the PC output but 
is still in the radio output.

Mike, K7SR


> Date: Thu, 18 Jun 2015 11:18:56 -0700
> From: Mike F <mikecf100 at gmail.com>
> To: hpsdr at lists.openhpsdr.org
> Subject: [hpsdr] Audio output noise
> Message-ID: <55830B90.90707 at gmail.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> My Mercury based system (Mercury, Penelope, Metis) has developed a
> problem.  Operated the system and then didn't turn it on for about 5
> days.  When I turned it on everything appeared to be operating, but when
> I applied power both the speakers and the headphones had a noise that
> sounds somewhat like digital data.
>
> The noise continues when mute is pressed.
>
> The noise continues when in transmit mode.
>
> The noise condition doesn't change with changes in the volume, even when
> the volume is at 0.  This is true of both the master volume and the
> rx1/2 volume controls.
>
> The system is fully functional.  When operating, signals can be heard,
> and change level with the volume control.  The noise is still present.
>
> I tried to record the noise with the volume turned to 0.  The recorded
> file had no output, although it was the length of the recording period.
>    I do hear recorded output with the volume up but I believe that it is
> the band noise, without the described problem.
>
> I tried a different power supply.  Nothing changed.
>
> Cycled power and rebooted the computer, no change.
>
> Reconfigured PSDR to default values. No change.
>
> Haven't successfully tried a different computer.  Tried psdr 2.3? but
> couldn't get by the firmware check.  Tried 3.2.9, problem same. Present
> PSDR 3.2.24
>
> Just prior to the problem Windows 7 did an update.  The system is based
> on the Intel ZEON processor.
>
> HELP!