On Apr 5, 12:22 pm, hank wrote:
To David and others...

Great posts, reviewed the Buffalo WHR-HP-G54 Router specs. Flashing with
dd-wrt.V24_AAP-0130-wrt54g.bin seems easy.
I'm curious about what board-level mods you made. If you could
eventually post pics (if you do the job again), that would be great.
Any issues with the simple dropping resistor (to 5v) using boat power?

Hank S.
Ft. lauderdale

It appears I will be making another set up for a friend in about a
month or so, so I will be posting pics at that time.

Here are the board level mods:

1. Spin the antenna connector 90 degrees so that the antenne wire and
ethernet cable come out of the same side of the board

2. Scrape some components and traces off the board below the ethernet
ports and run jumpers over to the power jack. This provides POE
connectivity without having to have a bunch of other boxes or boards
in the housing. VERY clean!


I rigged up a voltage meter to a specially wired RJ45 keystone jack.
I hooked this jack up to the ethernet plug at the top of the mast. In
my electrical panel where I inject the POE power, I used a
potentiometer in line with my house battery power. I turned up the pot
until the voltage meter at the top of the mast read 5V. I then
measured the resistance of the pot and but a resistor of the same
value in line. I don't recall what the value was, but I could check if
you liked. It is important that you use a trial and error process like
this as the conductors in the ethernet cable are so small and the runs
so long that the voltage drop is significant. In my system, the round
trip distance is about 120'. To get a handle on what is at play here,
check out:

http://www.powerstream.com/Wire_Size.htm

You can input wire sizes and runs and calculate voltage drop. Cat5
cable is usually 24 ga., but each leg uses 2 conductors. If you
convert the twin cross sectional areas to the most appropriate wire
guage, it comes out close to 21 ga. That guage is not an option in the
calcuator, but 20 ga. is. Even at that guage, voltage drop is
calculated to be over 20%. You can see that distance of the run is a
very big factor here.

I was a little concerned that cahrging voltages would mess with my
system. But 14V/12.7V is only a 12% difference and so far has not
shown any adverse effect. YMMV and if it does, let me know about your
experiences.


David
S/V Nausicaa