Cable-Tronix CT-FMM User manual

INSTALLATION MANUAL
CT-FMM
Fixed Channel Audio/Video Micro Modulator
1

PACKAGE CONTENTS
This package contains:
One CT-FMM Fixed Channel Audio/Video Micro Modulator
One CT-FMM instruction manual
PRODUCT DESCRIPTION
The CT-FMM is a professional grade fixed channel micro modulator providing an audio and video
modulated RF carrier from 54 to 806MHz on any CATV channel from 2 to 125. Any standard
video source can be used, including satellite receivers, demodulators, VCRs, DVD players, and
TV/security cameras.
The CT-FMM employs highly stable synthesized frequency control. Setup and tuning is easy and
straightforward taking advantage of the unit’s front panel access to all level controls and
indicators. Channel frequency information with FCC offsets is programmed into each unit at the
factory. Non-volatile memory maintains channel selection in event of power loss.
The CT-FMM meets or exceeds government regulatory requirements, including FCC group delay
pre-distortion for color transmission, and FCC Docket 21006 aeronautical offset requirements.
Note: The CT-FMM cannot be used as an audio only modulator. Video must accompany an
audio input for the unit to function properly.
2

SPECIFICATIONS
CT-FMM
Fixed Channel Audio/Video Micro Modulator Specifications (Typical)
RF
1. Output Frequency 54 – 806 MHz. CATV Channels 2 – 125
2. Output Level +50 dBmV typical
3. Output Level Range 20 dB Adjustable
4. A/V Ratio -12 dB to -18 dB (± 2dB) Adjustable
5. C/N Ratio 60 dB typical
6. Broadband Noise -78 dBc
7. Spurious Output >60 dB
8. Frequency Accuracy ±25 kHz
9. Output Impedance 75 Ohms
10. Output Return Loss 12 dB
VIDEO
1. Video Input Level 0.7 Vp-p (Min.) @87.5% Modulation
2. Video Impedance 75 Ohms
3. Differential Gain 4.5% @87.5% modulator
4. Differential Phase 4.5˚@87.5%Modulation
5. Video S/N Ratio 62 dB
6. Input Return Loss 20 dB
7. Flatness ±1 dB
8. Group Delay Response Meets FCC group delay pre-distortion
requirements for color transmission
AUDIO
1. Input Level 0.35 V – 1 Vp-p for 50 kHz Deviation
2. Input Impedance >10k Ohms
3. Flatness ± 1dB, 50 Hz – 5 kHz
4. Harmonic Distortion <1%, 50 Hz – 15 kHz
GENERAL
1. DC Input Power 5V (400mA), 12V (150mA)
2. Operating Temperature 32 ˚F ~ 122 ˚F
MECHANICAL
1.Dimensions 1”(W)” x 3.5 (H) x 7.5” (D)
2.Weight 14 oz.
3

INSTALLATION AND OPERATION
NOTE TO SYSTEM INSTALLER
System installer must adhere to Article 820-40 of the NEC tha
t
provides guidelines for proper grounding and specifies that the
cable ground shall be connected to the grounding system of the
building, as close to the point of cable entry as practical.
1. UNPACKING and HANDLING
Each unit is shipped assembled and factory tested.
Ensure that all accessories are removed from the container before discarding packing
material
2. MECHANICAL INSPECTION
Inspect the front and rear of the equipment for shipping damage. Make sure the equipment is
clean, and no connectors are broken, damaged, or loose. If equipment appears to be
damaged or defective please contact your distributor or Cabletronix at 1-610-429-1511 for
assistance.
3. THE USE OF RACK MOUNTABLE CHASSES AND POWER SUPPLIES
The CT-FMM is designed to be mounted in a rack chassis designed for micro modulators,
and powered by power supplies intended for micro modulators and designed to fit in the
micro modulator rack chassis. The Cabletronix CTRC-12 12-unit rack chassis and
Cabletronix CTPS-12 12-unit power supply should be used with the CT-FMM. Up to 12 CT-
FMMs can be configured into a single CTRC-12/CTPS-12.
Some chassis and power supplies from other vendors and distributors may also be used, but
actual configurations will vary by vendor. It is critical to note that (a) the power supply
harness being used MUST come from the vendor providing the power supply, (b) the power
supply must be designed for powering micro modulators and installation in a micro modulator
rack chassis, and (c) power supply harnesses and power supplies are NOT always
interchangeable among vendors. Using the wrong power supply harness and/or power supply
can damage the CT-FMM. Contact your distributor for more information.
4

4. PRODUCT DIAGRAM
FRONT, REAR, and SIDE PANELS
5

1 Audio Modulation Deviation Level
(Volume Control) Adjust for 25KHz deviation
2 Video Modulation Index Level Adjust for 1 to 1.5 Vp-p @87.5% modulation
3 A/V Adjustment Adjusts the picture carrier to audio sub-carrier
ratio of the output signal
4 RF Output Power Adjustment Adjusts individual modulator overall RF output
5 Video Input F-connector
6 Audio Input RCA Jack
7 DC Power Input 3 Pin Locking Header
8 RF Output F-connector
9 In-band Channel Adjustment Port Connector for adjusting CT-FMM channel
within its specific band
5. HARDWARE CONNECTIONS
a. The CT-FMM is designed for installation in a chassis designed for micro modulators.
Micro modulator chasses such as the Cabletronix CTRC-12 can be mounted in
standard 19” EIA racks.
b. The Cabletronix CTRC-12 12-unit rack chassis and Cabletronix CTPS-12 12-unit
power supply should be used with the CT-FMM. Up to 12 CT-FMMs can be
configured into a single CTRC-12/CTPS-12. Some chasses and power supplies from
other vendors and distributors may also be used, but actual configurations will vary
by vendor. Contact your distributor for more information.
c. The CTRC-12 rack chassis can hold up to 12 CT-FMMs and other micro modulators
and demodulators of the same size. However, note that some other products such
as the Cabletronix CT-AHP require two slots in a CTRC-12 resulting in the chassis
supporting 6 units instead of 12.
d. When configuring the CT-FMM in the chassis and power supply it is critical that the
power harness being used is from the same vendor as the power supply, and is
designed for that specific supply. Power supply harnesses among vendors are not
interchangeable and can severely damage the CT-FMM.
e. The use of a surge protector is highly recommended. Product warranty does not
cover surge damages.
f. Connect a 75ohm coaxial cable with proper connectors from the source’s Video
Output port to the CT-FMM’s Video Input port (F-female connector).
g. Connect a 75ohm coaxial cable with proper connectors from the source’s Audio
Output port to the CT-FMM’s Audio Input port (RCA female connector).
h. Connect a 75ohm coaxial cable with F-connectors from the CT-FMM’s RF Output
port to the headend combiner.
6

6. CHANNEL SELECTION
a. The CT-FMM is a fixed channel modulator. Channel adjustment is possible, but only
within the band for the specific CT-FMM purchased.
b. The optional CT-FCP frequency control panel is required to adjust a CT-FMM’s
channel within its specific band.
c. Remove the panel covering the CT-FMM’s In-band Channel Adjustment port.
d. Power up the CT-FMM.
e. Attach the CT-FCP wiring harness to the CT-FCP, then attach the CT-FCP to the CT-
FMM’s In-band Channel Adjustment port.
f. Push the respective Up / Down Buttons to set the desired channel. After about 15
seconds the channel will be automatically stored in the modulator’s memory. In the
event of a power outage the channel will be automatically recovered.
g. Disconnect the CT-FCP from the CT-FMM and replace the In-band Channel
Adjustment port panel.
7. ADJUSTMENT
a. After installation and completing all hardware connections power the unit and wait 20
minutes before making the following adjustments.
b. For testing purposes no more than 15dB from the RF Output should be going to a
TV or RF input monitor. Use an attenuator to reduce the signal level if testing with an
RF Input monitor. Individual CT-FMM setup and level settings can be tested from the
RF Output port. However, system level testing should be done from the combiner.
c. With a nominal 1 Vp-p video source connected, use the Video Modulation Index
Level control to adjust the video modulation level for correct percentage of
modulation (87.5%) if the video input is greater than 1.5 Vp-p. If test equipment is
not available then adjust for proper picture contrast when viewed on a TV monitor
and compare with known Off-Air broadcast picture quality. Turn the level control
clockwise to increase the video modulation index, counter-clockwise to decrease the
video modulation index.
d. With audio source connected, adjust Audio Modulation Deviation Level control on
the front panel for 25 kHz deviation. If you do not have an audio modulation meter
and a precision demodulator, use a TV set or a signal level meter with an audio
speaker and adjust for equal volume as compared to a known Off-Air broadcast.
Monitor for a few minutes to assure the maximum volume does not over modulate,
which can cause picture distortion. The audio modulation deviation can be increased
by turning the level control clockwise, counter-clockwise to decrease the audio
modulation deviation.
e. To adjust the picture carrier to audio sub-carrier ratio of the output signal, rotate the
A/V Adjustment on the front panel. Clockwise to increase the audio carrier level,
counter-clockwise to decrease the audio carrier level.
7

f. To adjust the output rotate the RF Power Adjustment control on the front panel.
Clockwise to increase output, counter-clockwise to decrease output.
8. TROUBLESHOOTING
a. Ensure you are using quality multiple shielded cables with quality radial or
compression F-connectors. It is recommended Belden 9167 cable be used to
prevent signal ingress and egress.
b. Ensure the F-connector’s center conductor is making solid contact with the CT-
FMM’s Video Input, Audio Input, and RF Output ports.
c. If the CT-FMM is receiving power but no signal, check to be sure the video and/or
audio input cables are securely connected with their respective Video Output and
Audio Output ports on the video source and the Video Input and Audio Input ports on
the CT-FMM. Also ensure the cable is securely connected at the CT-FMM’s RF
Output port and the combiner’s input ports.
d. When taking measurements it is always best to use a quality signal level meter. For
initial individual CT-FMM setup measurements may be taken from the unit’s RF
Output port. System level measurements, however, should be taken from the
combiner’s output.
e. It is highly recommended the CT-FANRK 3-unit rack mountable fan be used as
significant heat reduction may double the CT-FMM’s life span.
f. Further troubleshooting assistance can be found on-line at www.cabletronix.com in
addition to support from Cabletronix sales engineers at 1-610-429-1511.
8