Olson Technology OTM-4000 (PAL I) - Manual (Page 10)

025-000336 REV X2 Page 10
AUDIO IF IN
This is the aural IF input to the SAW filter / output converter section. The AUX IF switch is AFTER
this input. The aural IF level at this point is relative to the video IF level as at the unit RF output. IE:
If the A/V ratio at the output is 15dB, then the aural IF level at this point would be approximately 15
dB below the video IF level at the VIDEO IF IN connector (approximately +23dBmV).
In normally configured applications this input is usually connected to the AUDIO IF OUT
connector. The OTM-4000 I is shipped from the factory with this jumper in place.
AUDIO IF OUT
This is the aural IF output from the IF modulator section. The aural IF level here is relative to the
video IF level as at the unit RF output. IE: If the A/V ratio at the output is 15dB, then the aural IF
level at this point would be approximately 15 dB below the video IF level at the VIDEO IF IN
connector (approximately +23dBmV).
In normally configured applications this output is usually connected to the AUDIO IF IN connector.
The OTM-4000 I is shipped from the factory with this jumper in place.
VIDEO IF OUT
This is the video IF output from the IF modulator section. The video IF level here is +38dBmV.
In normally configured applications this output is usually connected to the VIDEO IF IN connector.
The OTM-4000 I is shipped from the factory with this jumper in place.
VIDEO IN
1 Volt P-P baseband video input to the OTM-4000 I. When VIDEO AGC is enabled, the modula-
tion will remain constant for input level changes of
± 3dB.
AUX SELECT
When these two terminals are connected together, the AUX IF IN is enabled. This is a “hard”
control and will override any other function that instructs the internal IF to be selected. The left
terminal is chassis ground and the right terminal is grounded to activate the function.
AUDIO IN
Baseband audio input to the OTM-4000 I.
This input is configurable for 600 Ω balanced or high impedance unbalanced applications. When
configured for high impedance input, ground should be connected to the right-side terminal.
To change from 600 Ω to high-impedance input, disconnect the unit from AC power, remove the top
cover and locate jumper “JMP1” near the front left corner of the circuit board. Move the jumper
from the position marked “BAL” to the position marked “UNBAL”.
If it is desired to defeat the audio pre-emphasis for some reason, locate the jumper marked “JMP2”
and move it from the position marked “PRE-EMPH” to the position marked “BYPASS”.