This section is primarily dedicated to spectrum analyzer
screen shots
of various return path conditions and the associated
opinions of what
all the squiggly lines mean. The opinions are basically
mine based upon
personal experience, or derived from the accompanying
comments and/or
descriptions of screen shots provided by others.
While hardly the definitive source of answers to "What
the hell is that crap?",
this site is simply here to hopefully help those who
may be just getting
their feet wet regarding return path problems and
are staring at
their analyzers saying, "Whuh?".
Please send comments, opinions, questions, contributions,
etc., to:
Poge@Pogenostics.com
Useless return spectrum. Downright nasty stuff. Notice the reference
level of 48.8 dBmV.
(Courtesy - Jim Kuhns)
This is what your return should resemble when it's 'all good'. Notice
the ref. level of 18.8 dBmV.
The above represents the input to a LanCity LCe derived from
over 130 Jerrold actives.
No fiber. No trunk segmentation. Just a whole bunch of older architecture
working like it's
supposed to when properly aligned and high pass filters are utilized
on all one-way drops.
( Courtesy - Poge Smit )
Zenith BPSK cable modem traffic centered at 12MHz. Notice the harmonic
at 24Mhz.
(Courtesy - Poge Smit)