[arm-allstar] BBB URI USB-HUB Distorted Audio

[Joel Jameson]

Have you matched the ohms for the output of the radio to the input of the
URI ? Checked the audio levels with a deviation meter, and gone through the
simple-usb setup?

If you've done all that already, you might need an isolation transformer
(and/or opto-isolate on the control pins) from the URI/Fob to radio.

Cheers,
Joel
W0KGW

Cheers,
Joel
W0KGW

On Thu, Jan 1, 2015 at 1:42 AM, Randy Neals <randy at neals.ca> wrote:

>
> I've been experiencing a distorted audio problem while setting up a BBB
> with powered USB-HUB, DMK URI, and USB Keyboard.
>
> The audio distortion is noticeable on audio from the node. (transmit audio)
> To eliminate/isolate the issue I swapped out the URI for a SYBA USB Audio
> FOB and PC speakers.
> Still the same background hum/distortion. So that eliminated RF
> interference, ground loops, the URI and the radio.
>
> Through further elimination, I have identified that when my USB keyboard
> is connected to the USB HUB, the hum/distortion is louder. (URI through USB
> HUB to BBB, no Keyboard)
>
> And then have compared the audio when not using a USB hub at all, and I
> think there is a further improvement in audio, although not as major as
> when the keyboard is /is-not connected.
>
> My next troubleshooting step is to swap out the keyboard, and then swap
> out the USB HUB.
>
> The USB Hub I'm using is an AmazonBasics 4 Port USB 3.0 Hub with 5V/2.5A
> power adapter
>
>    - Package includes: 1 USB 3.0 4 Port Hub / 1 5V/2.5A Power Adapter / 1
>    built in 10 inch USB 3.0 cable / 1 Owner's Manual
>    - Compatible with USB 3.0 and backwards compatible with USB 2.0
>    - Support Low speed (1.5 Mbps)/ Full speed (12 Mbps)/High speed (480
>    Mbps)/ Super speed (5 Gbps)
>    - Support auto switching between self-power and buspower mode
>
>
>
>
> _______________________________________________
>
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> arm-allstar at hamvoip.org
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>
> Visit the BBB web page -
> http://www.crompton.com/hamradio/BeagleBoneBlackAllstar/
>
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