TRANSMITTERS

Encoded message is send on video during vertical blanking line no. 16 to 22. The digital message is sliced from video at remote receiver end and compared with reference digits.

If all digits are matching National programme is selected. If it fails for three successive line change over to Regional takes place. The specifications of different parts are as follows:

Encoder Specifications

1) Video In :- 1 v pick to pick standard I/P, 0.3 v Sync signal.
2) Video Standard :- Pal B/G.
3) Line Selection :- Any line selection between 16 to 24
4) O/P :- Serial Data O/P at the 256 KBPS during selected vertical line.
5) Serial O/P Level :- 0.4 v peak with reference to clamp level.
6) PSU :- 230V ± 10% A/C.
7) Mechanical :- 19" standards rack mount model with 1U height.
8) Line Selection :- Through DIP switch inside the unit, front panel controls.
9) Mode Selection :- Auto /Manual.
a) Auto Mode :- Receives TTL command from either PC or from any remote
controller.
b) Manual mode :- Receives TTL command from front panel switch.

10) Monitoring :-

a) Manual Indication.
b) Auto / Manual Indication.
c) Status of selected program (National / regional).
d) DC Voltages monitoring point.

11) Input Connectors

a) BNC Female: - 1 V Peak 75 Ohm with loop through facility.

12) Output Connectors

a) BNC Female: - 75-Ohm digital output at 256 KBPS rate.

b) Output Monitor :- BNC Female 75 Ohm digital output at 256 KBPS rate

Decoder Specifications

1. Input power :- 24 V DC nominal.
2. Input voltage range :- 21 to 29 V DC.
3. Video input :- BNC female 1 V Peak to Peak standard composite video with loop back facility.
4. Line selector :- Any line between 16 to 24 with DIP switch inside the unit .
5. Change over selection.
a) Auto :- When received code matches with selected data automatic change over to regional program. By default National program is selected. In case of power failure also national program is selected.
b) Manual :- National / Regional program can be selected manually through FP switch.

Specifications for switch

1. Video amplitude :- 1V peck to peck
2. Sync :- 0.3V peck to peck
3. DG :- ± 2%
4. DP :- ± 2°
5. Noise performance :- Better than 56 dB
6. Connector :- BNC female 75 Ohm impedance.

Specifications of Audio

1. Level: - + 10 dBm into 600 Ohm Bal.
2. Freq. Range: - 50 - 20,000 Hz.
3. Freq response: - ± 0.5 dB for 50 Hz to 20,000 Hz.
4. Connector: - 5 Pin audio.

Monitoring Point

1. Display :- a) Line voltage (24 VDC input)

b) Display of selected program (National / Regional)

Mechanical

1. 19" Standard rack mount with 1 U height.