Fracarro OPT-TX-DT Operations Instructions download pdf (Page 15)

English

SAT

1. Input signal level: 69-86dBµV

The input transponder level to the OPT-TX DT must be between 69 and 86dBµV for the

ACG to function correctly.

2. Band ﬂatness: 4dB

The transponders should be equalised within the same polarity so that the maximum

difference in level between the transponders transmitting through the ﬁbre is 4dB, to ensure

the receiver is able to receive correctly.

4.3 Output levels to the OPT-RX DT optical receiver

The output level to the OPT-RX DT optical receiver depends on the number of signals transmitted

through the ﬁbre and the optical attenuation of the section.

Remember that 1dB of optical fall equals 2dBµV of attenuation to the electric level (RF).

Below some reference levels are given for the output signals to the receiver:

TV (DTT/CATV)

The overall output power is -27dBm (82dBµV) with 21dB of optical attenuation which means that

the fewer multiplexes that are transmitted, the better the output level and quality.

RF output level per MUX

No. of Muxes Receiver optical Input -8dBm Receiver optical Input -14dBm

40 73dBµV 61dBµV

16 77dBµV 65dBµV

8 80dBµV 68dBµV

4 83dBµV 71dBµV

Table 1 Indications of output levels to the OPT-RX DT – TV signal

N.B.: 1dB optical equals 2dB at electric level (RF).

SAT

The typical output SAT signal level to the OPT-RX DT is:

• 74dBµV for transponders with an optical level of -14dBm input to the receiver (21dB of optical

attenuation)

• 86dBµV for transponders with an optical level of -8dBm input to the receiver (15dB of optical

attenuation)

FM and DAB

The FM and DAB signal levels respect the difference of input level in relation to the TV signal.

N.B.:

The signal levels to the user sockets must respect the set points given in the EN50083-7 standard

(DTT: 45-74dBµV – SAT: 47-77dBµV). In certain cases the RF output signal from the receiver, or if

possible the input optical signal, will have to be attenuated by means of passive components such

as optical line faders.

5. TYPICAL INSTALLATION EXAMPLES

Some example diagrams are available at the end of the manual and on the website www.fracarro.com

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 23 24

No comments

Fracarro OPT-TX-DT Operations Instructions Page 15