Force 2804 Troubleshooting guide

825 Park Street, Christiansburg, VA 24073 • USA [phone]• TEL [phone] • FAX [phone] • csr[email protected]m • www.forceinc.com
© 2005 by Force, Inc. Force reserves the right to make changes to the product described in this document in the interest of product improvement.
Model 2804: Professional
Distribution Solution (PDS) 110
Channel Transmitter
Installation Guide and User Manual
IOM2804
Revision 5.2, November 2005
Warning
The optical emissions from the chassis and connected optical fiber are laser-based and may present eye haz-
ards. Follow all safety precautions
Technical Support
If you encounter any kind of problem after reading this manual, contact your local distributor or a Force, Inc.
Applications Engineer. To reach technical support:
On the Web: http://www.forceinc.com
By Phone (Monday through Friday 8:00 am to 5:00 pm EST): USA [phone]
TEL [phone]
By Fax: [phone]
By Email: [email protected]

Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
2IOM2804 Revision 5.2
Contents
Prefaceii
Section 1 Product Technical Bulletin1
1.1 Product Overview1
1.2 FCC Notice1
1.3 Optical, Video, Electrical Characteristics2
1.4 Environmental and Physical Characteristics2
1.5 Specification Notes2
Figure 1.1 In-Band Frequency Response of the 2804T
and 2808R Link2
Figure 1.2 Expanded Frequency Response of the 2804T
and 2808R Link3
Figure 1.3 CNR vs. Rx Optical Input and Channel Loading
(2804T/2807R)4
Figure 1.4 Transmitter Level per Channel vs. Number of
Channels5
Figure 1.5 Transmitter Level/Channel vs. Log10 (Number
of Channels)5
Figure 1.6 Response of Model 2804 RF Power Meter6
Figure 1.7 Top Label Used to Determine RF Input for
Transmitter6
1.6 Applications7
Figure 1.8 Professional Distribution Solution with Return
Path7
1.7 Part Numbers8
Section 2 Installation Instructions9
2.1 General Installation Requirements9
2.2 Items Provided9
2.3 Items Required9
2.4 Inspection10
2.5 Equipment Rack Configuration10
2.6 Measuring RF Input Levels at the Transmitter10
2.7 Connections11
2.8 Front Panel Physical Description12
Figure 2.1 Transmitter Front Panel12
2.9 Rear Panel Physical Description13
Figure 2.2 Transmitter Rear Panel13
2.10 Safety Precautions13
2.10.1 Laser Safety Procedures13
2.11 Shipping and Handling Precautions14
2.12 Storing the Unit14
Section 3 Operating Instructions15
3.1 Connections and Power-up15
3.2 Performance Verification16
3.3 User Maintenance17
3.4 Repair Service17
3.5 Cleaning17
3.5.1 Optical Connector Cleaning Equipment17
3.5.2 Directions for Optical Connector Cleaning18
3.5.3 Connector Handling18
3.6 Troubleshooting18
3.7 Problems and Comments19
Index21

3IOM2804 Revision 5.2
Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
Product Specifications
Optical and Video Characteristics: @ 25 °C, SM Fiber (Note 1)
Electrical Characteristics
Physical Characteristics
Min. Typ. Max. Units Notes
Channel Loading 110 Ch.
Bandwidth 40 870 MHz 2
Operating Wavelength 1290 1310 1330 nm
Optical Output Power (P/N ends in /06) +6 dBm 3
Optical Output Power (P/N ends in /08) +8 dBm 3
Optical Output Power (P/N ends in /10) +10 dBm 3
Optical Output Power (P/N ends in /12) +12 dBm 3
Optical Output Power (P/N ends in /13) +13 dBm 3
Required Fiber Bandwidth 2,000 MHz 4
Input/Output Impedance 75 Ohms
Side Mode Suppression Ratio (SMSR) 30 dB
Backreflection Tolerance -50 dB
Carrier-to-Noise Ratio (CNR) See Figure Figure 3 5
Composite Second Order (CSO) -65 dB
Composite Triple Beat (CTB) -69 dB
Input Signal Range (per ch.) See Figures 4 and 5 6, 7
Min. Typ. Max. Units Notes
Power Supply Voltage 120 240 VAC 8
Power Supply Frequency 50 60 Hz 8
Power Dissipation 25 Watts
Fuse (Slow-Blow) 1.25 A 9
Min. Typ. Max. Units Notes
Weight 5.5 lbs.
2.5 kg
Physical Dimensions 19 W x 1.72 H x 14.1 D in.
483 x 44 x 358 mm

4IOM2804 Revision 5.2
Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
Environmental Characteristics
Specification Notes
1) The Model 2804 has been tested and found to comply with the limits for a Class A digital device, pursuant
to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful
interference when the equipment is operated in a commercial environment. This equipment generates,
uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruc-
tions in this manual, may cause harmful interference to radio communications. Operation of this equip-
ment in a residential area is likely to cause harmful interference, in which case the user must correct the
interference at the their own expense. Compliance with applicable regulations depends on the use of
shielded I/O cables. The user is responsible for procuring the appropriate cables.
2) Figure Figure 1 shows the typical frequency response of a 2804 link over the specified frequency range.
The gain flatness is typically ±1.0 dB over this range. The flatness is typically less than ±0.1 dB over a
standard 6 MHz channel bandwidth. See Application Note AN123 for additional information on North
American Television Frequencies.
Figure 1 In-Band Frequency Response of the 2804T and 2808R Link
Min. Typ. Max. Units Notes
Operating Temperature Range 0 +45 °C 10
Storage Temperature Range -20 +70 °C
Humidity (RH, non-condensing) 0 90 %
-20
-15
-10
-5
0
5
10
Response (dB)
012 345678910
Frequency (Hundreds MHz)
2804T
with 2807R
2804T with
2808R

Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
IOM2804 Revision 5.2 5
Figure Figure 2 shows an expanded view of the frequency response of a typical 2804T/2808R link.
Figure 2 Expanded Frequency Response of the 2804T and 2808R Link
3) All optical power levels are average values. Output is Class IIIb laser.
4) Be sure to compute your fiber bandwidth (end-to-end) as well as attenuation.
The Model 2804 incorporates an optical isolator in the laser package that reduces the effect of optical
backreflections on the laser performance. However, all analog lasers are affected by optical backreflec-
tions. The 2804 can only achieve published performance levels if the fiber between the transmitter and
receiver has a maximum optical backreflection of -50 dB. Optical backreflection levels above -50 dB will
increase the noise floor of the laser (i.e. decrease the carrier-to-noise ratio), worsen both CSO and CTB
performance, increase passband ripple, and dramatically increase cross modulation. The result will be a
noisy, grainy picture with diagonal bars.
Force, Inc. recommends that all fiber connections be SC/APC type, FC/APC type or fusion spliced. There
is some folklore which suggests that the only critical backreflection is the one closest to the transmitter.
Our experience does not support that view. We find that all backreflections matter, regardless of their dis-
tance from the transmitter.
2804T
with 2807R
2804T with
2808R
Response (dB)
Frequency (MHz)
-10
-8
-6
-4
-2
0
2
4
6
8
10
40 122 204 286 368 450 532 614 696 778 860

6IOM2804 Revision 5.2
Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
5) Figure Figure 3 presents a tremendous amount of performance data for the 2804 link. The horizontal axis
is the amount of optical light that reaches the receiver. (It is not the loss between the transmitter and
receiver.) The vertical axis shows the carrier-to-noise ratio at a given optical input level.
Figure 3 CNR vs. Rx Optical Input and Channel Loading (2804T/2807R)
Typical transmitter output is +10 dBm, so a received optical power of +2 dBm corresponds to an optical
loss of 8 dB. The vertical scale is the carrier-to-noise (CNR) ratio. Six curves are plotted against these
axes. The top curve is the typical result when only 5 channels are transmitted through the link. It can be
seen that very high CNR results and in fact the output is quite usable with receiver optical inputs as low as
-12 dBm, corresponding to 22 dB of optical loss! As the channel loading gets higher, the maximum achiev-
able CNR drops.
Note that the link CNR is usually specified for a received optical power of
-3 dBm or more. Thus, a 2804TK-SCAP/12 optical transmitter, with an optical output of +12 dBm, will
provide optimal performance with up to 15 dB of optical loss at full channel loading. If lower channel load-
ing is used, then the link can operate at higher optical losses and still provide exceptional CNR.
6) The recommended RF input level is shown in Figures 4 and 5.
Both figures show the same information, the transmitter level per channel versus the number of channels
being transmitted; however, in Figure Figure 5 the horizontal scale is a logarithmic scale. This shows that
the underlying relationship is linear if plotted against the logarithm of the number of channels.
WARNING
Exceeding the recommended RF input level may instantaneously destroy the transmitter.

Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
IOM2804 Revision 5.2 7
Figure 4 Transmitter Level per Channel vs. Number of Channels
Figure 5 Transmitter Level/Channel vs. Log10 (Number of Channels)
Figure Figure 6 shows the response of the Model 2804 transmitter’s integral RF power meter. This meter
is accessed via pin 5 of the 9-pin D-sub connector on the rear of the transmitter.

8IOM2804 Revision 5.2
Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
Figure 6 Response of Model 2804 RF Power Meter
7) Each transmitter has a label such as the one shown in Figure 7 that gives the RF input levels for the trans-
mitter. The individual carrier levels should closely match each other to ensure consistent performance on
all channels. In all cases, set the composite RF input level so that the RF INPUT LEVEL LED is green.
The RF indicator LED only operates properly for rated channel loading and a flat input spectrum. To use
the chart, look up the channel loading you will be presenting to the transmitter input and read off the drive
level per video carrier. For instance, with 40-channel loading, each video carrier should be about +25
dBmV.
Figure 7 Top Label Used to Determine RF Input for Transmitter
8) The Tx rear panel power module can accept voltage levels from 120 to 240 VAC at 50 to 60 Hz.

Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
IOM2804 Revision 5.2 9
9) Fuse Rating is 1.25A, Slow-Blow.
10) Most parameters are relatively unaffected by varying temperature. A moving air environment is recom-
mended at ambient temperatures above +35°C.
11) The CATVLinx®VSB/AM Fiber Optic Link is optimized for single-mode operation only. Use on multimode
fiber is not recommended, even for short distances, because of the large amount of modal noise that could
result.
CAUTION
Risk of fire. Only use fuses with same type and rating as marked.

10 IOM2804 Revision 5.2
Model 2804 Professional Distribution Solution (PDS) 110 Channel Transmitter User Manual
Installation and
Operation
General Installation Instructions
The installation of these units is very simple. There are no special unpacking instructions, except that care
should be taken to handle units gently. Fiber optic links are sensitive electronics devices that should be han-
dled with care. Like most electronics, they are susceptible to ESD. Proper ESD techniques, such as wearing a
wrist grounding strap, should be observed at all times when handling a unit. The units should not be dropped.
No assembly is required.
Do not install the equipment near sources of excessive heat, such as furnace outlets or above heat producing
units, such as large power supplies and tube-type equipment. Observe temperature and relative humidity
requirements specified in Section , page 4.
Items Provided
The following is a list of items provided with each Model 2804 PDS Fiber Optic Video Transmitter:
Items Required
WARNING
Potentially hazardous uninsulated voltages exist beneath the top panel.
Qty. Mfr. P/N Description
AR Force, Inc. 2804TX-SCXX/XX CATVLinx®110 Ch. PDS Transmitter
1 per connec-
tor Any Any Active Device Receptacle Cap for Optical and RF Connec-
tors
2 per unit Force, Inc. 2804.342-2 L-Bracket Mounting Ears. Allows the table top Tx chassis to
be adapted to a 19" wide rack.
1 per unit Any Any Three-wire ground AC power cable.
Qty. Mfr. P/N Description
AR Force, Inc. 2807RX-SFXX CATVLinx®PDS/PNS Mini-node CATV Receiver
AR Force, Inc. 2808RX-SFXX CATVLinx®PDS/PNS CATV Receiver
4 per unit Any Any 6-32 Panhead Mounting Screws with Lock Washers and
Nuts (used to mount receivers)
1 Any Any Straight Screwdriver
AR Any Any EIA standard 19" rack with hardware to install the transmit-
ter into the rack.