[App_rpt-users] A and B audio output from USB fob on a RPi running DIAL

[Ramesh Dhami (VA3UV)]

On 7/10/2016 4:08 PM, Kevin Custer wrote:
> Running 3 nodes on the DIAL release is likely not going to work.  You 
> may want to try Doug and David's release which uses a different 
> channel driver.  I've never heard anyone having luck running more then 
> 2 nodes on the Raspberry Pi release in full DSP, but I have heard of 
> success with the other.
>

Hi Kevin and all:

Wow - lots of discussion going on today, so I will jump in help divert 
the discussion!

So... for one of my 220 repeaters, I did confirm that the USB fob I was 
using was one of my earlier versions, which only had one audio output - 
hence the reason why I was not able to get the 'split' PL working - doh! 
- my bad ;).

My 2nd 220 repeater (yeh, I have 2 x 220 machines that I am lucky enough 
to be working on at the same time!) - this is a pair of Bridgecom BCM220 
mobiles (identical to the radios used in the Bridgecom 220 repeater 
package) - this repeater is connected to a fob where I did bring out 
both audio channels.  So hence, I am able to split the PL and inject 
that into the 'data' input of the BCM220 radio.  This works well - so 
all good there!

What I am observing is that I have some high frequency noise on the 
audio out of the Bridgecom TX radio; it's subtle, but it is there.  One 
thought that I had is whether this was coming off discriminator of the 
RX radio.  I turned the RX radio off and the noise is still there.  Now 
coincidentally, I saw a message scroll by the display on the TX radio 
"PLL UNLOCKED" - ta da... is this synthesizer whine that I am hearing??? 
- I am going to test with a local mic tonight and see if the noise is 
still there (independent of the USB fob / app_rpt, etc...).

Running 3 full-duplex nodes on the Pi - I've been doing that for 
sometime; the difference now is the radio's - the RPi 2 and fobs are the 
same.  I didn't have this issue before.

More to follow... but for now, I wanted to provide an update and get us 
back to a technical discussion! ;).

Cheers,

Ramesh.