Maximum voltage on oscilloscope

[Sparkie]

Hi guys I'm a newbie here so please bear with me. I have a Tektronix TDS2000B and would like to look at the waveform on the output tubes but the manual says the maximum voltage to ground is 300V. Is there some way to do this or do I need a different scope? Thanks in advance for any help you guys could give me.

[Euthymia]

Use a 10X probe.

[Sparkie]

10X probe data

I checked the scope manual for the probe and it reads as follows.
"The P2220 probes have a 6Mhz bandwidth with a rating of 150Vrms CAT II
when the switch is in the 1X position, and 200Mhz bandwidth with a rating of 300Vrms CAT II when the switch is in the 10X postion"
Still confused Are there probes which have higher voltage ratings? or are these catagory ratings?

[Steve Conner]

Those are ratings for safety/legal/insurance purposes. The actual voltage it can take before breaking down and blowing the front end out of your scope is likely to be somewhat more.

However, I'd still rather use a proper 100x high voltage probe for looking at the waveform on output tube plates, especially with an expensive DSO. If a high powered amp is having a bad day, the plates can see spikes of thousands of volts.

The 100x are also better for probing around preamp stages, as they only load the circuit 1/10 as much as a 10x does. (but even a 10x is 10x better than a 1x :-))

I like the Isoprobe II from Multi-Contact, it's reasonably priced.