Olson Technology OTM-3550 - Manual (Page 6)

025-000136 REV J Page 6
6) RF AND AURAL CARRIER LEVEL ADJUSTMENT
A) Using a field strength meter, set the video carrier to the desired level with the RF output level
adjust control. It is suggested that the operating level of the OTM-3550 be not less than 4dB
below the specified output level. If the output level must be lowered more than 4dB from the full
specified output level, a fixed attenuator pad may be placed at the unit’s output.
B) Tune the field strength meter to the aural carrier (4.5MHz above the video carrier).
C) Adjust the aural carrier level control to the desired level, typically 15dB below the video carrier.
CAUTION: Reducing the visual/aural carrier ratio to less than 15dB can result in high out-of-
band spurious signals in adjacent channels.
7) MISCELLANEOUS
A) The OTM-3550 is BTSC stereo compatible. It is shipped in the “mono” mode. To use a composite
BTSC baseband input signal the pre-emphasis must be defeated. Remove the top cover and move the
internal jumper plug from W2 “PRE” to W2 “BY”. This plug is located in the left front area of the
circuit board.
B) This unit is equipped with external video and audio I.F. loops. Each loop is connected with a
short “F” type coax jumper. If either jumper is disconnected or lost, the unit will not perform
properly.
C) If a scrambling unit is utilized with the OTM-3550, follow the instructions associated with the
scrambler. The video I.F. output level is +40dBmV, and the audio carrier level is determined by
the aural carrier level adjustment - typically +22dBmV @ 15dB A/V ratio.
D) This unit is equipped with a 0.5A slo-blo fuse. For continued safety and to maintain proper
performance of the unit, please replace only with an equivalent fuse.
E) A -20dB test point (type F connector) is provided in the rear panel.
F) When installing the OTM-3550 in an equipment rack, it is best to leave an empty rack space
above and below the unit to allow for optimum air circulation.