Digital Leveller - Accurate description ?

[Channel Hopper]

Teldis Digital Cluster Leveller for Limavady xmtr (TDCL/02)

Description
The Digital Cluster Leveller (DCL) is a device that has been designed for the simultaneous filtering and level control of digital and analogue terrestrial television services. The filters very effectively remove the spurious outputs generated by the set top box modulators. Each unit has up to six filter paths that are individually tuned to pass single or groups (clusters) of channels and to give as much rejection as possible to unwanted portions of the RF spectrum. Inherent insertion loss is low, between 3 - 4 dB. The DCL digital cluster levellers deal with channels in small groups carefully selected to suit the local transmitter. Although the DCL does not give individual control of each channel or multiplex, for most small system applications the level of adjustment that can be applied is more than adequate.

I am assuming this device is usually installed just after a rack of DTV units in a set of flats, but I have seen at least three this week in buildings where there is simply an aerial, and high gain amplifier distributing to a block of flats. What purpose would this serve ?

Am I missing something ?

 

[2cvbloke]

Sounds like a gimmick to me, a placebo effect type thing. If a setup works, then why change what's there?

 

[rolfw]

Similar units are used in an Integrated reception system for off air signals, it is so that you can adjust the signal strength of both analogue channels and digital multiplexes prior to launch, applying a slope where necessary.

Johansson Profiler Particularly useful if pulling from more than one transmitter.

Haven't really had much need to use them on my jobs, as most are not more than 12 apartments.

 

[Channel Hopper]

I would assume the most useful place for them would be just after the main amplifier, to suppress any spurious oubursts, from anything non digital (and a lot of the amps installed are definitely a decade in place.

But no, these are installed just below the aerial (or FM combiner).

somebody needs educating.

 

[rolfw]

The Profiler is also a launch amp.

 

[Channel Hopper]

Thanks

I will do some rewiring next week and take some measurements.

 

[A nonymous]

Would i be right in asuming you install IRS systems aswell Rolf

Small world isn't it

:-beer

Nano

 

[rolfw]

Yes I do. Mainly small ones though.