We had a couple of thefts from vehiclen in driveway. Planning to put
surveillance camera high on existing ham tower. Putting the camera at low
level is unacceptable for two reasons: 1. Need to see individuals behind
vehicles. 2. Need motion detection to not see busy traffic in street.
Camera uses ethernet cable for digitalvideo streams and power. It comes
with 100 ft CAT5e with standard connectors; I assume RJ45. The tower has
beams for 40 thru 2m, and dual band 2/70 vertical. In addition, the entire
tower/antenna farm will soon be used as a vertical for low bands.
Concern 1: Transient protection. Existing cables have transient protectors
close to the tower base, which is close to the entry to the house (no
separate protection panel on the house wall). For the camera cable I am
considering a protection device such as the Linx CAT6-75. Any cheaper
alternative out there? This device will be far removed from the actual
camera. I could add another protector at the camera, but what would I use as
the ground connection?
Concern 2: RF damage to camera, RF disruption of video. Camera documentation
warns that video may be affected by strong electrical or magnetic fields. I
am willing to accept that recorded video will be unusable for the times when
I am actually transmitting. I am not willing to accept physical damage to
the video equipment, nor to distruption of its operating state or
programming. Would it help to use shielded ethernet cable? I don't believe
the camera has a ground connection, but connects only to the twisted pairs.
I assume the pairs of a shielded etherent camble can use a standeard RJ45
connector, while the shield can be routed separately and connected to the
tower metal near the camera, and to the ground at the bottom of the tower.
Concern 3: Disruption of tower-as-a-vertical tuning by ethernet cable
running into the house. This concern applies to all the cables going to the
house. For the coax cables, the main remedy is grounding the shields at the
bottom of the tower, which happens at the transient protectors. This is to
be supplemented by ferrites if significant RF is detected on coax cables
entering the house. Ferrites will be the only remedy for the unshielded
rotor cable, as will as for the ethernet cable.
Does anyone have experience from a similar project? Am I likely to meet all
my goals? Any concerns or solutions that I have missed? Thanks in advance
for your comments.
73,
Erik K7TV
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