1. I thought of passing my own power through cat5 once. It would be nice if you had "tap-out" plugs, to where you could plug any old cat5 into them and it will move those 4 wires out for access.

Posted at 5:01PM on Mar 26th 2008 by Matt_

2. Great idea, I like this.

Matt_, it would be easy to make those "tapout" plugs. Small piece of Cat. 5e cable, 1 rj45, 1 Cat. 5e Jack, and voila ! (Don't connect the 2 pairs you need on the jack end)

Posted at 5:46PM on Mar 26th 2008 by DigitalMind

3. Putting the router in a plastic bag is a bit of a poor idea. I guarantee it will wrecked by moisture soon. Something like this would be far better: http://www.hyperlinktech.com/web/nema_enclosures.php

Posted at 5:59PM on Mar 26th 2008 by GCH

4. Personally though, I'm gonna leave the router inside, and run a COAX cable to the roof and "simply" replace the antenna of the router with a J-Pole antenna on the roof. Seems a lot simpler. Am I missing something ?!

Posted at 6:26PM on Mar 26th 2008 by DigitalMind

5. digitalmind, the only thing you have to worry about is how much cable you run and the quality of the cable. each foot of cable you will lose a little dB.

Posted at 6:57PM on Mar 26th 2008 by l1oyd

6. @digitalmind:
might get a lot of loss or interference on the antenna coax. i dont think they can be very long unless heavily shielded.

could be wrong though.

Posted at 6:58PM on Mar 26th 2008 by dext3r

7. Now that I think about it, I'm not sure I'd want my power supply hooked directly to a twisted pair in cat5.

...Now I just gotta connect these two wires....and POP, power supply shuts down from short. At least the fan is salvageable if it dies.

Posted at 7:01PM on Mar 26th 2008 by Matt_

8. The motivation for getting the device as close to the antenna as possible is signal loss in the cable. At 2.4 GHz coax cable is *very* lossy. For example, good RG-58 cable has a loss of 18.3 dB per 100 feet at those frequencies. In only a 16 foot run you'll lose 3 dB, which is half your signal. It's even worse for thinner types of coax, like RG-174.

This isn't a problem you can solve with more shielding; it has to do with the foam dielectric between the inner core and the outer shield, which becomes lossier with higher frequencies. The only way around this, besides using very short cable runs, is to use waveguides, which are very unwieldy -- hooking them up is more like plumbing than wiring.

When constructing an outdoor enclosure you need to think about condensation as well as water intrusion from rain. In commercial enclosures the usual practice is to either include a small "breather" hole on the underside and include a heat source to drive out moisture, or place a packet of silica gel inside the enclosure before sealing it to dry the atmosphere inside.

Posted at 7:20PM on Mar 26th 2008 by Orv

9. @ ORV

Random question. Are you a ham? You seem to know your way around feedlines :D

Isaac, KD0BRD

Posted at 7:57PM on Mar 26th 2008 by kd0brd

10. Cable loss is always a factor, but there's always the right kind of cable to extend WHATEVER you want (to a point) properly.
I use RG-8 Cable for my Ham radio installations.
-Digital Mind
VE2RIF

Posted at 9:01PM on Mar 26th 2008 by DigitalMind

11. and won't a j-pole tuned for 2.4ghz be *really* small?

Posted at 10:10PM on Mar 26th 2008 by andrew

12. Is the inclusion of the TV tuner in the diagram relevant to the project at all?

I've been far a use of the last 2 pairs... Though, if all your using it for is sniffing Wifi, why bother with serial, just use ssh!

Posted at 11:28PM on Mar 26th 2008 by atrain

13. would be nice if there were actual pictures of the cable. or the ends at least...

Posted at 11:42PM on Mar 26th 2008 by dmang

14. @atrain

In early project planning, the idea was to use the fourth pair to send the audio and video from the camera on the roof through the cable to the desktop computer. (Who doesn't want a video camera on the roof?) When I realized that a serial cable is much more important, I swapped out for a wireless camera, and used the fourth pair for console. The wireless camera leeches power from the router, and needs a wireless receiver.

The reason the serial console is important, is the ethernet connection is not always available. For instance, during boot time, and when reconfiguring the interfaces. Nothing more secure than a hardline ;)

Posted at 12:20AM on Mar 27th 2008 by Steve DiRaddo

15. seriously ghetto (my fave was the silica pack in the router rofl) but *l'esprit de hacker* is worthy of an approving nod

my improvements would be:

- weatherproof enclosure; many avail for WRTs
- tap out the PoE and Serial neatly in the enclosure
- use a simple 2-port RJ-45 box to breakout on the far end; use the Cisco-style pinouts and a decent cable
- high gain antennas of course

Posted at 2:21AM on Mar 27th 2008 by Rich

16. Very cool.

Interestingly enough, I just made my own PoE injector for my aironet access point last night. Hackaday must have been reading my mind...

Posted at 2:55AM on Mar 27th 2008 by Ken

17. Since Steve is on here, I'll just post this on here.

You're not taking the cable resistance into mind when powering it or putting serial data on it. At 100 feet, the cable should have a resistance of 5.16 ohms per conductor, so 10.32 ohms per V+/Gnd and TX/RX. If, on power, the router is pulling 1amp, you are dropping 10v, so only 2v would get to the router. I'm assuming its .5a or .25a, so dropping 5.16 or 2.58v, so you get 7v or 9.5v at the router. For the serial port, what power/logic levels is it running at? 5v? I doubt it's 12v. How much current is the router sinking for data?

Grab another 100 foot cable, add a 14ohm resistor to one end, and then 12v to the other end. It should pull .5 amps and measure 7 volts at the resistor. Adjust accordingly.

Posted at 4:20AM on Mar 27th 2008 by cde

18. Nicely done. I did something similar back when my router was a 100Mhz desktop PC - used the other wires in cat5 to control the 'power on' line of the atx power supply to switch it on from another room in the house.

Posted at 7:41AM on Mar 27th 2008 by jim macarthur

19. You need at least LMR 400 or 600 to run so you have little loss, but hardline is better. Now the cheap man's alternative is to use RG 6/U double shield, but it is 75 ohm coax, so you'll need an antenna analyzer to properly tune your antenna so you have a 50 ohm impedance at the radio.

I use Celwave 3/8" hardline for my rooftop wifi. It's affordable for less than a dollar a foot. Connectors are $20 a piece though. This runs to a high gain vertical, and I can reach out even further using my commercial equipment I have on the tower.

The best thing to do though is get yourself an amateur radio license, then you can get into the good equipment that you can put some power behind.

(The technician license should be a no brainer for anyone reading this site.)

Posted at 10:18AM on Mar 27th 2008 by Adam

20. @cde:

you read my mind. resistance in the cable should make the voltage at the router's end a bit lower. it seems the router is ok at the lower voltage though, otherwise it wouldn't be working.

Posted at 10:34AM on Mar 27th 2008 by andrew