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Freezing when Noise Source enabled (v1.4)

Posted: Mon Aug 19, 2019 2:36 pm
by k5cg
Installed the v1.4 version on a Pi3B+ connected to a KerberosSDR from an earlier shipment (borrowed from a friend).
The KerberosSDR is powered from a 3A USBC adapter.
The Pi 3B+ is powered by another 3A USBA adapter.
It doesn't seem to matter if I turn them on simultaneous or in sequence (KSDR, then Pi).
Blue LEDs in the KSDR come on.
I can connect to the KerberosPi SSID from my laptop and then see the Pi VNC desktop.

I set frequency, gain and click "Update Receiver".
I click Start Processing and I see the Update rate bouncing around; 380/390 ms.

Switch to the Sync page.
Enable sync display and the Update rate drops to 2.5 seconds. A flat spectrum display appears in ABS X Corr panel.
Enable Noise Source and the app freezes.
The only way to recover is power down the Pi and start over.

Re: Freezing when Noise Source enabled (v1.4)

Posted: Tue Aug 20, 2019 5:26 am
by rtlsdrblog
Hmm you might need to try another USB-C supply.

I've seen this happen once before when the USB-C supply is poor and causes a dip in power when the noise source is activated. That dip in power causes a the USB connection to drop.

Re: Freezing when Noise Source enabled (v1.4)

Posted: Tue Aug 20, 2019 4:29 pm
by k5cg
I'll have to find a strong USBA supply and get a USBA to USBC cable so I can put my USB(A) power analyzer inline to watch what is happening to voltage and current.

I will update with findings later.

Thanks for the reply.

Re: Freezing when Noise Source enabled (v1.4)

Posted: Wed Aug 21, 2019 10:41 pm
by k5cg
It works!

I switched to a pair of Samsung mobile phone AC adapters, the kind marked with "Adaptive Charging" - even though that feature is unused in this application. I chose these because they have 2 Amps output but more importantly provide 5.2 VDC.

The Pi consumes about 600ma and the KSDR about 1A while running idle. The KSDR peaks at 1.1A while syncing and zeroing IQ.

So far so good. Now for a drive test.