background image

Solutions to Common Problems 

 

5  Solutions to Common Problems 

In most cases, nearly every issue with the 

Cobra T2

 CAT 5 Video System can 

be resolved by checking the CAT 5 termination and making sure that it’s 

pinned to the TIA/EIA 568B wiring specification. However, there may be 

other problems that cause the system to not perform as it is designed. Below 

are solutions to the most common installation errors. 

Problem:

 

No video signal at the transmitter local port or at the receiver.

 

Solution:

 

Check that both units are powered.

 

Ensure receiver EQ adjustment is set correctly — turn knob 

slowly. 

Make sure the CAT 5 cable is terminated correctly per the 

TIA/EIA 568B wiring specification.

 

Is the display device powered on and functioning?

 

Check to ensure display settings (resolution, refresh rate, and so 

on) are compatible with input signal. 

In some cases, the video termination may be mismatched. The 

transmitters and receivers ship with 75-ohm termination as the 

default. To disable termination, see 

Appendix B

.

 

Problem:

 

Poor video quality.

 

Solution:

 

Have all receiver adjustments been finished? 

Ensure EQ adjustment is set correctly — turn knob slowly.

 

Check all cable connections. 

The video signal’s refresh rate may be set too high. Reset to a 

lower refresh rate in your monitor-configuration menu. 

There may be a delay skew issue. See the section on Skew in the 

receiver manual. 

There may be a DDC compatibility problem. See 

Appendix G

.

 

Problem:

 

Poor audio quality.

 

Solution:

 

Powered speakers are required. Make sure speaker power is ON. 

Check input source levels from the source device. Make sure the 

audio source is not overdriven or underdriven. 

Audio is summed left and right for “A” versions. If using a single 

channel, both audio inputs must be connected at the transmitter 

end for full audio gain. Audio is line level. 

S2 serial//audio units support full stereo line level. A high 

frequency noise may be heard if the CAT 5 cable from the 

transmitter is disconnected, or the transmitter is not powered up. 

This is normal and will disappear once a complete link connection 

is made. 

 

 

 

 

 

 

Summary of Contents for Cobra T2

Page 1: ...Kramer Electronics Ltd USER MANUAL Model Cobra T2 Video RS 232 Transmitter...

Page 2: ...Setting Sync Signal Output Termination 9 Figure 3 DC Restore AC Coupling Options 10 Figure 4 Cobra T2 Jumper Locations and Settings 11 Figure 5 Receiver Mounting Bracket 15 Figure 6 Mounting Bracket...

Page 3: ...ransmitter and this user manual2 The Kramer Cobra series products are not compatible with Kramer non Cobra series products 2 Getting Started We recommend that you Unpack the equipment carefully and sa...

Page 4: ...terminated on site or in an existing infrastructure should be tested before use to ensure compliance with the TIA EIA T568B specification Using incorrectly terminated CAT 5 cables can damage this pro...

Page 5: ...see Appendix A 4 1 Making the Connections This section contains figures showing connections with the specific Cobra Series models In general however the connection and setup procedure at both transmi...

Page 6: ...nections on the Single Port VGA RS 232 The Single Port Cobra T2 CAT 5 Video System with RS 232 supports video and full modem serial RS 232 signals over CAT 5 cable You can also use the transmitters an...

Page 7: ...h 75 ohm termination as the default To disable termination see Appendix B Problem Poor video quality Solution Have all receiver adjustments been finished Ensure EQ adjustment is set correctly turn kno...

Page 8: ...m devices must be the simplex serial type For assistance contact Technical Support See Appendix E for Serial board settings External switch for last unit in daisy chain Problem Green shift or green wa...

Page 9: ...Green Green Green C Y Y 8 Blue Blue Blue U 9 10 Gnd Gnd 11 Gnd Gnd 12 13 H Sync C Sync 14 V Sync 15 Gnd Gnd Table 2 Terminal Block PINOUT PIN Audio S2 Audio Simplex Serial S PDIF Audio Composite Vide...

Page 10: ...Solutions to Common Problems 8 Appendix A Cabling Pinouts Table 3 DB9 Female Serial connector Pin Full Duplex 3 wire S2 Simplex 1 DCD 2 RX RX 3 TX TX TX 4 DTR 5 Ground Ground Ground 6 DSR 7 RTS 8 CTS...

Page 11: ...board The settings disable enable the 75 ohm termination on individual units For instance changing a transmitter termination affects the local monitor port only it doesn t affect the receivers Conver...

Page 12: ...nels in the Cobra The CobraT2 transmitter has been designed with full DC restore capability A simple switch setting is all that is required The following diagrams show the switch location and settings...

Page 13: ...e configured at time of order and will have factory configuration indicated in the part number label on the underside of the unit The factory configuration may be changed or checked by using the follo...

Page 14: ...talled 1 Off 2 Off 3 Off 4 Off 1 Off 2 Off 3 Off 4 Off 1 Off 2 Off 3 Off 4 Off 1 ON 2 ON 3 ON 4 Off Composite S Video Component Video With Left Right Line Level Audio 1 Off 2 ON 3 Off 4 Off 1 ON 2 ON...

Page 15: ...e configured for various serial modes The SDB hardware configuration is done via jumper settings These jumpers are used to set the various modes of operation As shown below Both ends must be set the s...

Page 16: ...3 4 OUT 5 6 OUT 7 8 OUT 9 10 IN 2 Full Duplex 2 way Short 500 ft 19 2K 1 2 See Notes 3 4 See Notes 5 6 OUT 7 8 OUT 9 10 OUT 1 2 IN 3 4 OUT 5 6 OUT 7 8 IN 9 10 OUT 3 Full Duplex 2 way Long to 1000 ft 1...

Page 17: ...holds four units in a 19 x 1U rack Not shown are brackets for 8 units and brackets for series receivers and transmitters The 8 Unit Rackmount Bracket holds the mounted units like the 4 Unit Rackmount...

Page 18: ...the source sync polarity signals However some displays require a fixed sync polarity that is not possible to change at the video source NOTE Both transmitter and receiver must have the same settings...

Page 19: ...IMPEDANCE Video IN 75 ohms SERIAL CHARACTERISTICS Protocol Asynchronous transparent to data format transparent to data rates up to 19 2 kbps full duplex data rates to 115 kbps simplex half duplex mod...

Page 20: ...KRAMER SIMPLE CREATIVE TECHNOLOGY 18...

Page 21: ...or the latest information on our products and a list of Kramer distributors visit our Web site www kramerelectronics com where updates to this user manual may be found We welcome your questions commen...

Reviews: