Hi Bruce,
> I have a C3I audio connected to a Cat 300dx.
> As you increase the delay there a hiss that
> is heard. If you turn the delay off, the hiss is
> silent. Any Ideas?
That audio delay module uses two cascaded Reticon RD5108 bucket-brigade
audio delay chips. Bucket-brigade technology has been obsolete for many
years, replaced by better schemes.
The chips have a poor signal-to-noise ratio, and cascading them (for
longer delay) makes it worse. That's why you hear the hiss. You can't do
much about it.
Your board is a copy that C3I made of the original S-COM Audio Delay
Module. Just as well; the S-COM Digital ADM that came later was a
much better product. The design of the DADM is now owned by Integrated Control
Systems, which also sells the DADM.
73,
Bob
Bob Schmid,
WA9FBO, Member
S-COM, LLC
PO Box 1546
LaPorte CO
80535-1546
970-416-6505 voice
970-419-3222
fax
www.scomcontrollers.com
