Help me ID this problem please

[UMDRanger 0]

 

You see the diagonal lines, thats the problem.

 

Camera is a GANZ 3024 2-4mm, in an outdoor housing, serviced by 18-2/24-4 siamese with NVT in the camera and a balun at the headend.

 

It was orginally powered by 24 VAC transformer. I noticed the problem and thought maybe a ground loop or something. I tried different transformers on different circuits.

 

We have swapped the AC transformer, camera, NVT, and balun; pulled new cable; and today I switched it to a DC 12v transformer.

 

It is a temp install covering the construction of a pool. The camera is mounted on the side a deck, approximately 2.5 stories up. (thats real fun on the ladder... even moreso today in the rain and mud )Wire is ran under the deck, under a door into the house where it goes through an exercise room and then into a bedroom closet where the DVR, monitor, and power supply are. (this is the same job as the Dedicated Micros DVR problem I asked about 2 months ago... the job from hell it seems). Total length of cable is approximately 50' It runs along 110v about 1' away with the cable being on strung along the floor near the wall (see electrical outlets) in the house. It passes about 7 feet from what I am guessing is a 220v outlet for a tanning bed, which is off. I pulled the cable to the center of the room, away from all the outlets... and still had the problem.

 

If viewed at the camera via a spot monitor using the supplied plastic video line clip the image is clear of all the interference/distortion. However, once it gets down to the DVR closet, and viewed through the balun/24-4 then it gets the interfernce when viewed on the spot monitor

and when passed through the DVR. New cable does not appear to be damaged, nor did the old one. Am using 18-2 for power, blue pair for video, orange pair is not used (which is our SOP, and we have never had a problem with this before).

 

I am stumped, my boss is stumped, the homeowner wants to buy the setup once we fix the problem and the contractor is done using it... so we'd like to get it tracked down.

 

Thanks for your suggestions.

[kensplace 0]

Is the siamese cable same as normal twisted pair on the video and is it unshielded (should be unshielded, overall shield is ok, but no shield on each pair). Is it correctly terminated with 75 ohms at the dvr, probably this is switchable.

[rory 0]

Looks like a connection issue ... or the BNC input on the DVR .. did you try a new channel .. are there any other cameras? Is it PC based, if so make sure the card is in good and the connector is okay .. i get the same exact thing when i simply knock my RG59 that goes into my Geo card .. as I dont have my card screwed in .. yah know home PC and all everything is always open

 

Also, did you test yet running a 50' RG59 loosely from the camera to the DVR ..? And why a balun and cat5 instead of RG59, for just 50'?

[UMDRanger 0]

Looks like a connection issue ... or the BNC input on the DVR .. did you try a new channel

Not applicable as it shows up when plugged directly from camera to TV monitor via balun.

 

are there any other cameras?

no

 

Is it PC based, if so make sure the card is in good and the connector is okay .. i get the same exact thing when i simply knock my RG59 that goes into my Geo card .. as I dont have my card screwed in .. yah know home PC and all everything is always open

Is embedded OS stand alone Dedicated Micros Digital Sprite II 9 camera unit.

 

Also, did you test yet running a 50' RG59 loosely from the camera to the DVR ..?

I have done focus/aiming by using RG-59 from the camera to the spot monitor, and there were no problems.

 

And why a balun and cat5 instead of RG59, for just 50'?

Baluns are so much easier and faster than crimp/twist on BNC. And we have switched over to using siamese for about a year now... with no problems like this. Only need to pull one cable, instead of two. Plus, we can junction off the other pair, when the client wants to add a camera.

 

Is the siamese cable same as normal twisted pair on the video and is it unshielded (should be unshielded, overall shield is ok, but no shield on each pair).

It is unshielded. There are 2 twisted pairs, of which I use one for video.

 

Is it correctly terminated with 75 ohms at the dvr, probably this is switchable.

yes, and as said above, the problem is seen on the monitor when passed through the siamese.

 

[rory 0]

The main problem with Baluns are they are much flimsier than BNC connections, and ofcourse other cable related issues . (that 1' may not suffice with twisted pair as it would with RG59) .. should only use this method if it is really needed - like multiple building apps.

 

Id look at the connections, then if still doing it, run an RG59 with BNC to test it from the camera to the DVR. Just more likely to have issues with twisted pair and baluns ... so that could be the problem.

 

Siamese typically represents RG59 BTW ...

[kensplace 0]

Is there a possibility there could still be a ground loop, maybe the camera is earthed or something else at fault, if you have a active balun try that at the receiving end to rule out a ground loop.

[UMDRanger 0]

Thanks Rory for the terminology correction. I'll probably just pull some coax since that doesn't give any problems. I moved the current cable away from the otherwise 1' from the outlet, and had no difference.

 

Thanks all.

[CollinR 0]

I would try swapping baluns unless these were $.

 

 

I'm not going to stop your current track though, you should use siamese and not cat 5 on 50' runs.

[UMDRanger 0]

Just got back from replacing the cat5 with rg-59. It looks much better. Thanks again.