This refers to several recent blogs, so I needed to start a new category or it might get misplaced…
This refers to several recent blogs, so I needed to start a new category or it might get misplaced…
In discussions of carrier current and tests of the AMT5000 where some power-line signal carriage was suspected, there have been mentions that power-pole transformers can block the transmission from being carried any further on the A.C. wires.
For awhile I have meant to survey the scene and see where the nearest transformers are.
There is a transformer directly out front, but standing on the sidewalk I can see many poles in all directions but I cannot see any other transformers. That could mean that carrier current will do very well from here.
In the next few days I’ll travel around looking upward and get a more specific idea of where those transformers are.
Avoid The Road Block…Go Around It!
You can avoid all those pesky transformers by coupling to the neutral line and using an isolated earth ground. Then the signal will go past the transformers and continue down the line. Since a lot of power drops are overhead and the neutral leg serves as a tension relief and the two hots are wrapped around the neutral as the drop enters the home or business, the signal will also couple to the two hots lines a bit. But most of the signal will still be on the neutral line.
The quick coupling method is using an inductor of 10-20uH and a fat cap (voltage wise) of about 3Kv and a value of either .1 or .01 MFD and a 1 amp fast blow fuse. Not exactly a peak efficiency coupling technique but it will be good enough to send that signal down the line to determine whats going on.
Another simple method to CC coupling is taking that 10 foot long wire and wrapping it around an extension cord, like those used for yard work, not the skinny two wire type, but the rugged 3 wire/grounded extension cords such as the orange insulated type or yellow insulated type..aka heavy duty.
Just wrap the wire around the outside of the extension cord. Wrap it so that the wire itself can extend as far as possible around the extension cord for maximum coupling area onto the extension cord..which equals maximum coupling efficiency for that kind of coupling technique. It is safe, and quite effective.
RFB