[arm-allstar] Asterisk - Hum

[Eric Smyder]

Hello all:

I've been experimenting with HAMVOIP, on a Pi3 at the home QTH with a
BF-888s as my radio.  It is a remarkably good system and easy to
configure.  However, I'm having an issue.  It is actually the same issue I
noticed on the W3HZU 6 meter repeater.

The video links below exemplifies the issue.  When transmitting directly
from the repeater with the hand-mic the repeater sounds great.  When I
trigger the AllStarLink from Asterisk, or when the node makes an
announcement or identifies, there is a distinct tone or hum.  I get the
same thing on my Pi 3 at the house if I key the transmitter and speak into
the BF-888s.  It seems to be coming through the computer or being picked up
somewhere in the connections to the URI.  I have taken measures to shield
the wiring between the radio and the URI, but the hum is still there.

At W3HZU 6m AllStarLink
https://photos.app.goo.gl/OtJn3aK2ZRCd6cPs2

At the home QTH using the Pi3, where the hum is more noticeable.
https://photos.app.goo.gl/XsUC4on5t04LH6CS2

Has anyone else noticed this and is there something I can do about it?

Thanks,

Eric
N3FIX