EverFocus EHA-SRX - Manual (Page 6)

EHA-SRX
7. CABLE REQUIREMENTS FOR BNC CONNECTOR
7.1 Cable Types
The EHA-SRX allows a total signal attenuation of up to 43.5 dB along the cable between
devices. The actual maximum cable length depends on the attenuation characteristic of the
particular cable used. Generally speaking, the better the cable quality, the lower the signal
attenuation, thus the longer the distance the HD-CCTV video signal can be carried.
The following table gives examples of different cable types, losses and the distances that can
be achieved. These are only examples and the actual distance is determined by the attenuation
characteristic of the cable in your application.
The table below gives an orientation for achievable cable distances:
Cable Type Attenuation in dB at 1
GHz per 100 m / 328 ft Max. Cable distance in
m ft
RG-59 24 ~ 40 * 70 ~ 160 230~520
RG-6 15 ~ 35 * 100 ~ 190 330~620
RG-11, CATV-lowloss
cables
8 ~ 16 * 180 ~
<
250 590~<820
* Low quality cable may have higher attenuation
7.2 Cable Installation
Please make sure, that the coaxial cable is not squeezed at any position.
Also the max. bending radius defined by the cable manufacturer should be considered.
General rule: maximum bending radius = 10 x outer cable diameter
Bending creates pressure on the center conductor, causing it to move through the dielectric
toward the inside of the bend. This affects impedance and return loss and reduces the
maximum possible cable length.
Please try to avoid any BNC - adapter or any connectors in the BNC cable.
Looping HD-SDI signals by BNC T-connectors to other devices is not possible.
6