Running gqrx turns bias tee off

[Roger Hammond]

I'm running gqrx on a Raspberry Pi 3. If I run rtl_biast -b 1 from the command line, I see the power LED on my NOOELEC Sawbird +GOES LNA turn on.

As soon as I open gqrx, the bias tee voltage is lost. Any thoughts on where the problem may be?

[Alexandru Csete]

Perhaps the USB bus is reset due to high power load when you launch
gqrx. Could you try on a PC?

Alex

On Wed, Feb 6, 2019 at 6:25 PM Roger Hammond <kc0...@gmail.com> wrote:
>
> I'm running gqrx on a Raspberry Pi 3. If I run rtl_biast -b 1 from the command line, I see the power LED on my NOOELEC Sawbird +GOES LNA turn on.
> As soon as I open gqrx, the bias tee voltage is lost. Any thoughts on where the problem may be?
>

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[Roger Hammond]

I should have been more specific. 

I don't know if I'm losing voltage, but the LED on the LNA turns off when I run the gqrx.

The only PCs I have available for testing it on are all Windows machines.

I'll see what I can find out.

Thank you for the quick response.

I like your program gqrx, nice job!

Rog

[Alexandru Csete]

Hi Rog,

I just tested on a PC and I observe the same. However, you can add
bias=1 to the device string and that will enable the bias T, i.e.

rtl=0,bias=1

Unfortunately, there is no easy way to add this feature to the GUI
with the present backend.

Alex

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[Roger Hammond]

Alex,

Thank you so much!

I will give that a try.

Rog

[alex27riva]

Il giorno mercoledì 6 febbraio 2019 18:25:07 UTC+1, Roger Hammond ha scritto:

I'm running gqrx on a Raspberry Pi 3. If I run rtl_biast -b 1 from the command line, I see the power LED on my NOOELEC Sawbird +GOES LNA turn on.

As soon as I open gqrx, the bias tee voltage is lost. Any thoughts on where the problem may be?

I have the same exact problem with my RTL-SDR V3, but adding bias=1 in device string, cause the software to crash.