Cctv Using 2 Visbox Units

[ifindoubt]

Hi,

Having a few problems with a site, where I have installed 2 digital radio mel visbox units, one unit is for a camera in one shed and the other for a camera in another shed, the receivers are both located on the main shed approx 6" apart.

I have a cat5 cable running from the dvr to a join, then a cable running from the join to the 1st visbox receiver, and then onto the second.

Both receivers are powered separately from different power supplies, however I am using an 8-core to the 1st rec. and then from it to the second rec. both power supplies for the receivers are using the same 3A spur.

The problems I am having is major interference on both video signals when both sets of visbox's are in operation, if I disconect one, the other works ok, and likewise if I disconect that one and power up the other it works ok.

The both dont seem to work when operated together, I have tried a different 2 sets and still the same problem,and I'm going out to site tomorrow with another 2 sets.

Does anyone haveany suggestions to try?

many thanks,

Jordan

[digitalwitness]

Can you put more distance in terms of which channels they are using?

[ifindoubt]

do you mean locate both receivers further apart? if so would this help and how much further?

They are digital tx and rx and apparantly the channel is pre-programmed inthe factory and there is no way of changing the channel, the older analogue visbox had selectable 4 channels.

[Couger]

which mel units are they 2.4ghz, 4.8's ?

[ifindoubt]

i'm not sure off the top of my head, I'm pretty sure they are 2.4ghz though.

[Rulland]

Pretty sure they must have selectable channels somehow,wouldn't be much use else.

[ifindoubt]

they do not have selectable channels according to mel and videcon, as they are digital units they have them pre-programmed at the factory :? The analogue ones you could select channel 1 - 4

the distance between each transmitter and receiver is no more than 15-20metres. and are fitted on the outsides of tin sheds.

[fozzies]

Do you have yagi aerials? If so you could polarise one set horizontally and one vertically

[ifindoubt]

Ill give that a try, mate

[ifindoubt]

I have installed the 2 new units, before it was a horizontal scrolling type interference, and now it is like a slight ghosting of the image, it has impro ed the overall picture but its not great.