View of the modulator

...and the view after removing the flap covering main part

Top view. Push-buttons "+" and "-" serve to settle output channel, with the left side pot underneath the proper deviation of sound subcarrier is set, and the right lower corner pot sets RF output level of the modulator.

Termination load and mounting screws included

Output level adjustment allows to match the level to other signals within an installation, also concerning other connected in series modulators.

50 kHz is the standard modulation assumed for input audio signal of 0,775 V RMS. The adjustment of deviation allows to level the deviation when audio signal differs from the norm. The ultimate standard deviation can be obtained within range of 0,150-0,775 V. Correct adjustment is essential for equal volume levels on individual TV channels.

The standard depth of video modulation is 75%, however sometimes it can be useful to change it a little, e.g. when a source generates alphanumeric characters a bit exceeding proper limit. The possibility of setting video modulation factor within +/- 6% enables correction in such cases, optimizing the signal quality. In practice it is seen as no great change of brightness and contrast of the picture. Generally, when the original and converted by the modulator picture is of regular quality (no overmodulation), and sound is clear, no correction is needed.

RF carrier offset may be useful in case an interference occurs, and the working channels cannot be changed - otherwise this function is not used.

Main features:

To sum up - the TV standard and channel are set in a "soft" way using keys and the display. Sound deviation and output signal levels are set with pots. Additionally, some detailed signal corrections (if needed - see above) can be carried out (in a "soft" way).