techniques for probing high power with small signal test equipment

[buildafriend]

Does anyone know any techniques for this? While the reading would probably be manipulated I imagine a series shunt might help to at least see that there is a reading? I could obviously use a volt meter to see what's going on but seeing a nice sine wave or dBu scale is sometimes beneficial for comparisons between units.

 

[JohnRoberts]

I guess it depends on what you mean by high power?

Most bench test equipment can handle decent levels.

When I was working on my outlet tester I had to measure impedance at 500V and that required specialized equipment.

JR

 

[buildafriend]

this thread probably belongs in the chamber.

my apology, not enough coffee this morning!  ;D

 

[buildafriend]

I'm basically trying to figure out a way to use my cheap old hitachi oscilloscope and my system one AP to look at signals near the outputs of amps like Ampeg SVTs. It would be nice to come up with a box that could decrease the signal by an amount that does not cause damage to my small signal signal test equipment. Comparative analysis from one side to the other would generally provide enough information to troubleshoot, even though the numbers wouldn't be correct.

 

[ruffrecords]

Basically all instruments that measure big voltages pot them down so they fall into their comfort zone. I think is all you really need.

Cheers

Ian

 

[Audio1Man]

I use the Scope as input device. I have probes that are 10x, 20x, 50x & 100x for tube equipment debug. Many scopes have a rear output monitor, typical 1 volt levels. Use this monitor to feed the AP. I have calibrated my scope for linearity/distortion. The dynamic range is in the range 70-80dB. This is good enough for most uses.

This can be the same type of 10x or 20x probe for the System One, however it will be about 1Meg input without adding another buffer stage.  If you have a System Two or better make a AC BUFFER ONLY DEVICE to feed the AP. I have had several  System Two AP’s in my shop for repair where they had the DC mode invoked and HV voltage took out the internal buffer circuit (expensive repair). Both owners now have a probe adapter in front of the AP.

The input Z for the AP’s  are in the 100k & 15pf range and 200 volt max.
I hope this helps
Duke