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Jeff Liebermann Jeff Liebermann is offline
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Default Increasing Cable TV SIGNAL LEVELS

On Fri, 10 Feb 2012 11:47:54 -0600, amdx
wrote:

The Box is a CISCO RNG100
Only data I know how to get is;
Tuner 537.00 Mhz 2dbmv
TDC 75.25 Mhz 5dbmv
RDC 20.00 Mhz 30.0dbmv Yes 30.0


It's the same as the Cisco Explorer 1540C with some features removed
by Comcast.
http://www.cincinnatibell.com/shared_content/pdf/tv/exp1540_uguide.pdf

How to get into the diagnostics:
Press and hold SELECT on front of unit until the MAIL light
starts to flash, then press INFO.
Or
Press and hold PAUSE on remote until MAIL light starts to
flash (around 10-15 seconds), then press PAGE-UP (-).
On some remotes, PAGE (+) might need to be used instead.

I'll guess(tm) that TDC is downstream power, and RDC is upstream
power. (20MHz is in the frequency range used by upstream path).
30dBmV is acceptable as the upper limit is about 55dBmv. Remember,
this is dB's above 1mv into 75 ohms, not dB's above 1mw into 50 ohms.
dBm = dBmV - 48dB
So, your 30dBmv is really -18dBm

The downstream values are also in the ballpark. See:
http://www.dslreports.com/faq/16085
The numbers are for cable modems, but the levels should be similar for
DTV. The typical delivered values should be:
-10 dBmV to +10 dBmV "Recommended".
-11 dBmV to -14 dBmv / +11 dBmV to +14 dBmV "Acceptable".
-15 dBmV & +15 dBmV "Maximum".
5dBmV is fairly is good enough and should result in a usable picture.

See if you can excavate the SNR numbers. Maybe there's RF garbage on
the systems (oscillating distribution amp, ingress, whatever, etc).


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