[Premium-Rx] Cubic R-3030A microprocessor noise

[w3jn]

Hello the list.  Well, after some messing around with the new R-3030A I discovered that a good deal of the 
digital hash was emanating from the speaker wires.  To make a long story short, here's what I did to more or
less resolve it:

1)  left RX has shielded cable going from line audio to external audio amp.  Bypassed the audio line with .01
caps to the screw on the chassis that holds in the serial interface card.  Grounding the caps to the "ground"
screw on the terminal strip did no good at all.

2)  right RX is connected directly to a speaker.  Both speaker lines bypassed to ground in a similar fashion as
described above.

3)  screwed down all of the modules.  None of the screws were locked - I could hear the noise gradually decrease
as I tightened each screw.  Wonder why all of the modules were loose--?  This radio may have been assembled
from good modules robbed from other radios.

Noise level on 28 MHz went from -60 on the meters to <-100 using the shop antenna (which is in close proximity
to the receiver).

Now I gotta get rid of the AM hiss.  ALthough I perused the archives fairly thouroughly, I didn't see any cures mentioned.

73 John W3JN
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