Coaxial Findings

[Gerry]

I have seen this discussed before, but not much bench-data presented.  

Using Coaxial Cable as An Air-Core Transformer

Here is my setup..

- Slightly under 1,000 foot of RG59 coaxial cable on the original reel.  No Core.
- AC from source going into the center conductor
- Output is the shield of the coaxial.



Inputting 37.5V with 1.8 amp open circuit.  60 Hertz from a Variac.  Output to an 8Ω resistor.

There is a Phase-Shift when the secondary is Open or Closed. 
The input Current DROPS when load is connected or when the secondary is shorted



More to come...

When showing your scope waveforms it is important to note what channel is generating the trigger source trace. For instance: if your channel 1 is your trigger source and displaying the  voltage then you can tell whether the voltage leads the current or lags the current (which came first ? amps or volts) .  If the volts lead the amps then you can tell that your input circuit looks like an inductor. If your Yellow trace, the amps came first then your input circuit looks like a capacitor. This is a major consideration in your analysis of the circuit and its behavior.
If your scope has math function you can multiply channel 1 times chanel 2 to get a real time readout of input power vs time by selecting CH1 times CH 2. 
Just a suggestion

[Contact1]

I could not get this experiment to work properly.  How many feet of coaxial is needed?

[Jim Mac]

Hello,

Both scope traces were voltage, none were current.  Current was measured through input fluke multimeter.  One trace was input voltage from the source, the other was output voltage through the resistor.

I was using roughly 1,000 ft. of coaxial on a reel.  It was quad shield RG59, quite literally the best and highest shielded / quality 59 cable available.  The same stuff that headend CMTS's are wired with.  

I have no evidence this can lead to anything special. Just a report of the findings