Re: [EVGRAY] J ² = 1

Body

Hi Ole,

> On 22 Nov 2018, at 20:29, [email protected] [EVGRAY] <[email protected]> wrote:
> 
> Yahoo doesn't like to transfer the complete messages today even though the delay isn't too great. I completed the message history from the picture and hope it gets through.
> 
> To make your own BNC feed through get one male and one female 50 Ohm connector and an inductance free 50 Ohm resistor. Then connect them all in parallel. Instead of one 50 Ohm resistor perhaps use two100 Ohm resistors in parallel. The resistors must be able to dissipate the power at the max voltage across them. With a low impedance current shunt this voltage won't be great. The 50 Ohm feed through must be placed as close as possible to the input of the scope's input amplifier which means the BNC input terminal of the scope.
> 
> For high speed oscilloscope probes the inner conductor of the coax cables are made of resistive wire to dissipate energy along the wire. This reduces reflections when the signal reaches the ends of the cable.

Thanks! That makes sense! I will get some shunts, a 50Ohm coax cable and give it a try …

Best wishes,

 Andreas