Not sure if this is the right section, but here goes.
I need to insall an RB433 with an R52 and a 24dBi grid antenna at a client site later in the week. The antenna pole is being mounted onto steelwork that’s at the top of a warehouse. There are already holes for the pole mounting and there’s already a UTP point up there. The client says they had been planning the radio link for some time and had the cabling and engineering work done over time. I’m not so sure and think that there may have been other equipment that’s been pulled out.
Either way, there’s no electrical supply up there and I need to USE POE. My digital cable tester tells me that the UTP is 85 meters long. The client has a couple of POE injectors already mounted in their network cabinet. They also have a large 12V power supply that’s providing power to the POE injectors.
Now my question is, how much voltage loss will I get over 85m? Will the RB work properly?
The client isn’t keen on an extra 18V or 24V power supply in their cabinet so I need to know this will work, or I need to walk away now.
I would say if you’re using only one R52 radio you may get away with a 12V supply, however if you trawl this forum you’ll find many posts where people have had instability problems at 18V and have had to move to 24V. Most of these are trying to use multiple high power radio cards, so you might be lucky.
My issue is with the potential for voltage drop. According to my calculations, I’m only going to get around 9V at the other end of +/- 240 feet of UTP. I was wondering if anyone has ever run POE over such a distance.
FWIW I run a repeater with 1 x RB433AH and 3 x RB433’s, each with 3 x R52H’s. It’s powered from a single 12V deep cycle battery that’s charged through and a solar panel. I have no issues with 12V. There is no mains power up on the mountain in question.
Here’s pictures of the unit when it was still being tested on the bench.
