Olson Technology OTM-3550 (PAL B/G) - Manual (Page 2)

025-000315 REV B Page 2
OTM-3550-B/G
FREQUENCY AGILE PAL B/G
TELEVISION MODULATOR
1) INTRODUCTION
The OTM-3550 B/G is a frequency agile television modulator with an output frequency range of 48.25MHz through
547.25MHz. All channels are selectable by front panel DIP switches in 1MHz increments.
The OTM-3550 B/G offers high output level, typically +55dBmV. This unit has a very high out-of-band carrier to noise
ratio (>77dB) and uses SAW I.F. filtering, which allows virtually an unlimited number of modulators to be combined
without the need for external bandpass filters. The OTM-3550 B/G has low power consumption (12 watts @ 220 VAC)
for reliable long term operation.
2) CHANNEL SELECTION
Remove the front panel plate marked “CHANNEL SELECT” to expose the channel select DIP switches as shown in figure
#1. Output frequency selection is accomplished by setting these DIP switches to the correct code for the desired channel.
Locate the code for the desired channel frequency in Table 1 in this manual and set the DIP switches from left to right (The
13 left-most switches are used for channel selection).
CHANNEL SELECT OFFSET
0 0 1 1 0 1 0 0 1 1 0 0 0 0 1 1
0 = Switch in DOWN Position
1 = Switch in UP Position
Figure 1 Front panel DIP switches
The above example indicates proper switch settings for 206.25MHz
3) OFFSET OPERATION
The last 3 DIP switches on the far right are used to select offset operation with certain versions of the OTM-3000. On the
OTM-3550 B/G, the switch should be left set as shown below.
4) VIDEO MODULATION ADJUSTMENT
A) Connect a video source of approximately 1V p-p to the video input connector (75 ohms input Z) on the rear panel. The
video should be of a reasonably bright scene (commercials are usually excellent).
B) Rotate the video modulation level control slowly clockwise until the video over modulation LED just turns on. The
light may blink with differences in average picture level. CAUTION: If the modulation is set too high, compression
or lack of contrast will occur during high intensity scenes.
0 1 1