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Re: sweep?


Sweeping has 2 parts in a hybrid sys, the forward channels and reverse spectrum (5-45 MHz), sweeping forward is mainly a comparison of the channels from the starting point (head end or node) to the dead end taps, any problems like: suck outs (low spots) or midband humps (frowns) ect.need to be fixed. to achieve this sweep process on the forward is by placing a wavetek transmitter in the headend, the transmitter must be setup properly in the headend so no sweep points are injected on a channel ( making the tv channel flicker) and try to achieve +7 telemetry  at the node using the wavetek , now you save that reference in your meter and compare every active using that reference, any suckouts or midband humps will show up using that reference at your new amp - le locations ect

Reverse sweep is the same process only backwards, just optimize the node, then get a reference at the node with the wavetek field unit, then compare each amp-le with that reference and maintain the flatness of the reverse bandwidth using eq's,(this process makes all the actives run the same db's as the node) If you have cable modems or digital box data in the reverse spectrum already , use the guard band feature in the transmitter so it does not inject sweep points in the used data area's,, also +7 reverse telemetry is the number wanted at the node by adjusting the telemetry level in the transmitter in the head end

node optimization is basically injecting a carrier at the node and receiving a certain level in the headend

remember telemetry is the freq channel that the transmitter and field units communicate with
and Sweep points are injected between channels, always check that the sweep points are 5 db under your loudest channel (usually digital channels run 10 db colder than the analogs do)






B2
This is CABL.com posting #296137. Tiny Link: cabl.co/mbpcz
Posted in reply to: sweep? by mrgreen
There is 1 reply to this message
Re: sweep? goodsky 3/18/2010 7:43:51 PM