User Manual

Technalogix Ltd. TM-100 Modulator

Video Conditioning Module

The TM-100 modulator includes a separate circuit board called the Video

Conditioning Module. The baseband video signal passes into the modulator,

through a group delay filter, and onto the video conditioning Module circuit board.

This module accomplishes two processes:

1. Sync Stretch. Allows the user to adjust the sync level to maintain the

proper level. Adjustment is made via potentionmeter VR2 and can be

made through the ventilation holes in the modulator lid without having to

remove the lid. Potentionmeter VR1 adjusts the video modulation level

and must be made by either removing the lid and adjusting VR1 or by the

Video Modulation adjust on the front panel of the modulator. The sync

stretch is powered by +5Vdc brought in to the connector and –5Vdc,

which is generated on board by U1.

2. Video Detect. Turns off the 24Vdc supply to the final amplifier in the TM-

100 in the event of missing video input. The power supply for the final

amplifier (+24Vdc) is routed through a relay on the circuit board. In the

event of a missing video signal, the relay contact is opened and the

+24Vdc is disconnected from the final amplifier.

The input and output impedance of the Video Conditioning Module is 75-ohms

and video connections are made via RCA connectors. The video Conditioning

Module can be bypassed, if necessary