USB Cat-5 Extender powered from NEAR end

[N9JIG]

I have a need for a USB extender to allow me to mount a couple radios in the attic connected directly to the antenna. One would be my ADSB receiver and anther would be an SDR. I am also thinking of experimenting with a standard scanner up there as well.

I have had good luck using USB Cat-5 extenders in the past but they all seem to require power at the far end rather than the near end. Where the radios will go in the attic is too far away from the only outlet to be practical without a long extension cord and I really, really want to avoid that.

Has anyone been able to find a USB extender that is powered from the near side rather than the far?

 

[mmckenna]

You mean something like this:

USB 2.0 Ethernet Extender Hub 4-Port Over Cat5/Cat5e/Cat6 (60M/196FT)

WEme 4-Port USB 2.0 Ethernet Extender Hub is an extender for USB over RJ45, by using Cat.5, Cat.5e or Cat.6 RJ45 LAN cable, it supports extension up to 60 meters/196feets.

www.alxum.com

Never tried them myself.

A guy I worked with for many years had a lot of property and set up a system using a lot of USB cameras. He used a home made Power Over Ethernet breakout to get power where he needed it. Pretty easy to break out the appropriate pins on an Ethernet cable and use them to haul power up to your radios.

 

[N9JIG]

This one has the power at the device end, I need it to be powered from the computer end so I don't need an AC adapter up in the attic.

Thanks though!

 

[mmckenna]

This one has the power at the device end, I need it to be powered from the computer end so I don't need an AC adapter up in the attic.

Thanks though!

OK, you can still split off the unused pairs from the Ethernet cable and utilize those. But, I'm not sure how many pairs the USB adapters use. If there's a spare pair, just haul the 5vdc up there.

 

[bharvey2]

My guess is that the USB extenders require that the power be supplied at the far end because the 5VDC would drop to too low a voltage by the time it reached the other end of the cable. I ran in to a similar problem when I was installing older analog video cameras at work that required 12VDC at the camera. I ended up using a 24VDC power supply in our main rack and stepping that down to 12VDC at each camera with a small regulator. Sure its a PITA but what about applying the same principle in your application?

 

[N9JIG]

I am thinking or running a separate cable (probably Cat 5 cable of which I have a ton) and running the DC power across that.

I could also see if the power connectors are the same size as used for my security cameras (which are also the same as used by Uniden scanners) since I have some extension cables left over from that project. Not quite as elegant as I hoped but I guess it will work.

The distance from the shack to the antenna is less than 25 feet, 12 feet up and 12 over so there should not be too great a drop in voltage.

 

[mmckenna]

Voltage drop can be overcome by increasing conductor size.
Or, utilizing more conductors. If a twisted pair 24 gauge cable had too much voltage drop, you could utilize additional conductors. If you are going to use some CAT5 for -just- power feed, then use 4 conductors for positive and 4 conductors for negative.

Or, like BHARVEY said, run 12 volts up there and regulate down to 5vdc.

 

[bharvey2]

Using CAT5 would be a good idea. With all of the PoE appliances that exist, you're bound to find an off the shelf product to use to split off your power to your devices.

 

[N9JIG]

Voltage drop can be overcome by increasing conductor size.
Or, utilizing more conductors. If a twisted pair 24 gauge cable had too much voltage drop, you could utilize additional conductors. If you are going to use some CAT5 for -just- power feed, then use 4 conductors for positive and 4 conductors for negative.

Or, like BHARVEY said, run 12 volts up there and regulate down to 5vdc.

I think the second run of Cat-5 cable is going to be my oyster. I will select two pairs for the positive and two for the negative and run that up.

My alternate to this is the use of one of those camera extension cables from the outlet that is up there by the air-handler if it will reach and if the plug size matches.