DC to daylight

[Felton, Robert]

This is a term used by radio operators and monitors for years, and means
something similar to "full spectrum," as in "He monitors frequencies from DC
to daylight."  The statement would identify somebody who listens to longwave
broadcasts in the 150 KHz range all the way to satellite communications in
the multi-GHz range.  Now, I notice the expression appearing in tech mags to
mean something akin to "full service."  Has anybody else seen this?  Does
anybody know where it originated?

Robert M. Felton, P.E.
Technical Editor, InTech Magazine
ISA - The Instrumentation, Systems, and Automation Society
67 Alexander Drive
Research Triangle Park, NC 27709

E-Mail: rfelton at isa.org
Phone: (919) 990-9223
Fax: (919) 549-8288