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RF Processing & Distribution
Amplifiers
Headend
Isolation Amplifiers
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| Part Number: QRBA , QRCIA - 550, 750, 870 |
Description:
The QRBA is used as the last amplifier before feeding the trunk or laser outputs from the headend. Franchise or node-specific channels of video or digital signals may be reused in many different areas of the cable system. QRBA prevents signal feedback that can cause co-channel interference with similar channels on the same frequencies fed to other trunks or fiber nodes. This allows clear local access channels, customized advertising insertion channels, RF modems and telco signals to be sent to targeted franchise areas.
Each of the independent RF amplifiers utilizes a single hybrid with impedance match to a built-in 15 dB directional coupler assembly (optional 10 dB coupler available upon request). Mounting the coupler after the hybrid inside the amplifier chassis reduces the number of cables and outboard directional couplers in the headend cable lash-up. Each amplifier also has a forward facing RF output test point calibrated at -30 dB. Each hybrid has a separate heat sink for optimum cooling.
Input signals from a "master" channel line up are coupled through an optional pad and equalizer and amplified by the hybrid gain stage. This gain stage provides nominal forward gain, but more importantly, offers reverse isolation typically equal to the gain of the hybrid plus 5 dB. The reverse isolation of the hybrid combined with the directional isolation of the 15 dB coupler can provide 55 dB or more isolation for forward broadcast signals to each path.
QRBA also uses 17 and 21 dB push-pull hybrids.
QRCIA is the same amplifier with a 13 dB hybrid followed by a 13 dB output pad for unity gain and maximum isolation. |
Features:
 Newest Hybrid Technology
FIVE Independent Amplifiers
Plug-in Hybrids & Accessories
>55dB Combining Isolation
Power-Doubled Options*
U.L. Transformer & DC Powering
3.5-inch Rack Mount Design
550, 750 or 870 MHz |
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