Fte maximal MEDIAMAX MINI S2 CT HD User Manual download pdf (Page 97)

User’s Manual - mediaMAX MINI HD

ENGLISH

Reserved of technical modiﬁ cations and/or errors

rev 1.2

the carriers have a similar level, remaining almost hidden. We can also see how the EDM variable

keeps at 0% when it does not detect any ECHO in the tuned multiplex.

The frequency response is almost ﬂ at for all the carriers (6816 carriers for an 8k DVB-T) in the

above screenshot. This means that the digital C/N for all the carriers is very good.

The following screenshot shows the frequency response for a carrier with a delayed signal of 2us

and with similar power than the main carrier. For this case the EDM value is 100%, which shows

that the ECHO is affecting noticeably the received signal.

The above screenshot shows the typical behavior of the frequency response when a clear echo is

present.

17.4.3. When to use the impulse response mode or the frequency response

The impulse response function is very useful when pointing antennas, as it will be possible to choo-

se the antenna direction in which the carrier echoes are the lowest possible.

The Frequency response function will help more to monitor the global signal quality (it is more visual

than simple C/N measurement), or to adjust narrow band ﬁ lters.

Note: If the echoes fall out of the guard interval, the signal will be almost impossible to decode. This

means that it will be also very difﬁ cult to lock, so probably the meter will not be able to analyze it.

1 2 ... 92 93 94 95 96 97 98 99 100 101 102 ... 115 116

No comments

Fte maximal MEDIAMAX MINI S2 CT HD User Manual Page 97