Our job is to recommend for Jim Henry, who is building an AMT5000 Radio Transmission site 150' from his studio, a best method for transmitting 12 VAC by wire from studio out to transmitter.
I'll put my recommendations here, inviting comment on accepting or improving what I suggest.
The wall-wart supplied with the AMT5000, at least in the case of my own transmitter and assuming Jim Henry has the same, is:
TRIAD CLASS 2 Power Supply
Model: WAU12-200; Input: 120 VAC 60 Hz 4 W; Output: 12VAC @ 200 mA
In previous instructions for building an audio line we described a home-built project box containing the parts for a simple audio mixer: stereo to mono and connecting lines from computer audio out to 150' audio transmission line.
In the same project box we suggest mounting a terminal block for voltage wire connections.
With the TRIAD Power Supply located where it can be plugged into the same AC Power Strip as the station computer, extend the existing AC output wire to the project box and cut the wire so as to neatly reach the terminal block for screw connection. Strip and tin the wires accordingly.
The corresponding screw terminals of the terminal block will be used to attach 150' of appropriate voltage transmission wire.
Jim, you have previously listed a stock of wire already on hand... please list that information here so readers can select and recommend the wire type they find best for the job;
At the transmitter end you can run the 12 VAC voltage line into the AMT5000 and connect to J5 Terminal block, next to where the audio line is connected.
The Terminal Block J5 is labeled [+ 12V -] because the AMT5000 can also be modified to accept DC voltage, but we are using the original AC supply, so connect the wires without concern of polarity.
If a shield exists on the wires, depending on what is recommended by others, connect it to the GND terminal;
Thoughts: For best AC line transmission twisted wire should be used. True or false?
With twisted pair wire no shield is needed. True or false?
System ground between computer and transmitter is supplied through the audio line shield. True. Any comments about this?
I strongly recommend against running 120 VAC home electric out to the transmitter. Any other comments or opinions?
There is no power off/on switch designed into the AMT5000, so you can add one by building an approprate on/off toggle switch into the project box. The TRIAD Supply will still be ON in such case, only the 12 VAC low power will be switched.
Turning off the power strip will turn off the TRIAD Power Supply.
What other ideas might anyone have?
