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| Thread ID: 75229 | 2006-12-21 03:40:00 | Very unusual video problem from a PTZ camera to a DVR | stuffed (1469) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 508414 | 2006-12-21 03:40:00 | A PTZ camera has operated fine for 18 months to a DVR 20 meters away. The DVR has been moved to the local police station – approx 160 meters and is connected via (TYCAB RG59 6/U Coaxial Cable MIL-C-17/29 XF 2006009) and a Cat 5 cable (for control). The picture is “disturbed” – has lines running up and down and freezes. It is camera 1. Other camera feeds to the DVR are fine and play in camera position 1 when switched. Have installed a Video Amplifier (CD-102-2 – transmission range 1000 meters) at the PTZ camera. Improved picture slightly. Tried a pair of baluns via the Cat 5 – small improvement. Now here is the catch – a small TV monitor placed at the DVR has an excellent picture!! Yet when try the VO from this TV to the DVR the picture on the TV becomes distorted. Tried another (smaller) Video Amplifier at the DVR end – the picture appeared much improved for about 5 minutes and then reverted! Have had a video expert in and he has gone away perplexed to seek advise – he claims we have done everything right. OK you guys out there – an big shout at one of our many bars for the answer!!! Will wait until ya come to town – but we would like to get this one sorted. Many thanks. |
stuffed (1469) | ||
| 508415 | 2006-12-21 03:52:00 | I have had similar problems, caused by "earth loops" Even though all power & video comes from the controller end, isolate the camera from the housing. Is camera power local or fed via Coax? |
Peter H (220) | ||
| 508416 | 2006-12-21 04:04:00 | Thanks - the camera power is local - 230 fed at the camera site. We have a similar PTZ camera and the picture is fine. How would you suggest we isolate the camera from the housing? Many thanks |
stuffed (1469) | ||
| 508417 | 2006-12-21 08:16:00 | Could it be that you have a difference in earth potential between the camera and the DVR? Try running the power for the camera and the power for the DVR from the same circuit. If this fixes it, you would need a ground loop isolator. They are relatively cheap, so worth a shot. I can't seem to remember the name of the company that supplies them (ie supplied them to the company that I work for) atm...I'll post back when / if I remember. Found the website http://www.wirednz.co.nz What you want is the 'video ground loop isolator' page 4 of this pdf www.wirednz.co.nz |
pine-o-cleen (2955) | ||
| 508418 | 2006-12-22 03:46:00 | If the camera mount is a single bolt - most are - make a bigger hole in the housing plate to clear the bolt. Then use isulated washers between the bolt head, casing & camera. The only earth on the camera must come from the coax. | Peter H (220) | ||
| 508419 | 2006-12-22 19:43:00 | Thanks guys - we have had dealings with Wired before and they have now sent an isolator for us to try - will keep you posted. I must say that Bruce from Wired would have to be one of the best have every had dealingS with - he is prompt and follows up to ensure all is ok. Cheers |
stuffed (1469) | ||
| 508420 | 2006-12-27 02:59:00 | The video ground loop isolator did the job thanks. Now who is gona claim the prize for sorting this out for us!! Cheers |
stuffed (1469) | ||
| 508421 | 2006-12-28 04:18:00 | Must have been an earth loop - I'm glad to see the problem solved. The beer will taste better now. | Peter H (220) | ||
| 508422 | 2006-12-28 05:07:00 | The video ground loop isolator did the job thanks. Now who is gona claim the prize for sorting this out for us!! Cheers Me me! It was me! :D :thumbs: |
pine-o-cleen (2955) | ||
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