User Manual E3
59300623 Rev.001
5.4.2018 10(20)
Return path
E3 amplifier supports 65 MHz, 85 MHz and 204 MHz return path. The return
path bandwidth is automatically set according to the installed diplex filters. If
diplex filter type cannot be detected, or the installed diplex filters are not the
same type, the “Unknown module” alarm is set and 65 MHz bandwidth is used.
Return path gain and slope control
Return path gain can be adjusted between -20 and 0 dB in 0.5 dB steps.
Return path slope can be adjusted between 0 and 15 dB in 0.5 dB steps.
The return path slope control pivot frequency is 204 MHz (slope measured
between 5 and 204 MHz) when 204 MHz diplex filters are installed, otherwise
85 MHz (slope measured between 5 and 85 MHz). Note that in 65 MHz
operation the signal level at 65 MHz is thus also affected by slope control which
has 85 MHz pivot frequency.
If diplex filters are changed so that the slope pivot point frequency changes, the
E3 software automatically readjusts return path gain and slope controls to
obtain similar frequency response.
RFF (Return Follows Forward) functionality
When forward path gain and slope are adjusted by the user, E3 software
automatically adjusts return path gain and slope accordingly. This RFF
calculation assumes that all needed forward path gain & slope is due to splitting
(flat) and cable losses between this and previous amplifier. If the forward path
output levels are the same for this and previous amplifier, RFF typically adjusts
return path so well that fine-tuning may not be needed at all.
RFF is enabled as factory default. It is automatically disabled if return path gain
or slope is adjusted manually. RFF can be re-enabled or disabled by the user.
RFF adjusts only gain and slope. It does not change return path input gain and
ingress switch settings and does not take these into account in calculation.
Return path input gain
The return path input gain can be used to add a fixed 10 dB flat attenuation to
the first return path gain control element. This can be useful in certain
situations, e.g. to force cable modems to transmit at higher levels resulting in
better SNR.
The use of return path input offset is similar to adding a return path input
attenuator plug to a traditional amplifier equipped with plug-in slot.
Ingress switch
Ingress switch can be used to attenuate return path by 6 dB or to cut it off
completely. The ingress switch can also be controlled remotely using Teleste
RIS system when E61 module is installed. Remote control overrides local
ingress switch control.
Teleste CATVisor Argus element management system supports SmartRIS
which can automatically control ingress switches and isolate ingress problems
based on ingress measurements in intelligent Teleste amplifiers and nodes.
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