Olson Technology LCM-6550 - Manual (Page 2)

025-000244 REV E Page 2
LCM-6550
TRIPLE, FREQUENCY AGILE - F.C.C. COMPATIBLE
TELEVISION MODULATOR
1) INTRODUCTION
The Olson Technology LCM-6550 consists of three frequency agile F.C.C. compatible television modulators
in a single 1-3/4" rack- mount chassis. The three modulator outputs are internally combined and amplified. The
LCM-6550 has a single RF output and each channel may be operated at +53dBmV typical, +50dBmV
guaranteed minimum. A high level (+36dBmV) combined visual/aural i.f. loop is provided for each of the three
modulators.
Each of the three modulators will operate on any standard or cable channel from 55.25MHz to 547.25MHz
(VHF channels 2 through 13 and cable channels 14 through 78). All channels are selectable by front panel DIP
switches and a front panel adjustment allows setting to F.C.C. offset frequencies.
The RF output from each of the three modulators may be turned off to facilitate trouble shooting or to allow
channel change without inadvertently interfering with other operating channels.
The LCM-6550 offers the unique Olson Technology feature of >69dB out-of-band carrier to noise ratio (from
the common output with all three channels operating). This unit uses SAW filtering for adjacent channel opera-
tion, and it provides 60dB of spurious free dynamic range. These features allow virtually unlimited numbers of
LCM-6550’s to be combined without the need for external bandpass filters.
The LCM-6550 has low power consumption (10 watts per channel @ 115 VAC) for economical and reliable
long term operation.
2) RF OUTPUT SHUTDOWN
If the output level control (marked “RF” on the front panel) for a modulator is rotated fully CCW, the output
of that modulator will be switched completely off. This feature may be used to facilitate trouble shooting or
to shut down an individual channel for any other desired reason.
It is suggested that this feature be used when changing channels on a unit whose output is connected to an
operating system. This will prevent the possibility of interfering with other channels as the channel select switches
are moved to their new settings.
After turning the RF control back up to switch the channel back on, the output level for that channel must be
reset to the proper value for your application.
3) CHANNEL SELECTION
Remove the small cover plate from the front panel to expose the channel select switches and the F.C.C.
offset adjustment control for the desired modulator. This switch and control is illustrated in Figure #1.