| Products > Test Equipment |
| Basic scope requirements except need to see ~10 ns pulses |
| << < (4/7) > >> |
| stephencox:
--- Quote from: tautech on March 06, 2024, 08:36:39 pm --- --- Quote from: tggzzz on March 06, 2024, 08:31:22 pm --- --- Quote from: tautech on March 06, 2024, 07:58:27 pm ---39kV 1000:1 2pF 50 MHz 900M \$\Omega\$ HVP-39pro fits the bill. --- End quote --- Make sure the voltage vs frequency derating curve is acceptable :) --- End quote --- OP states: like kHz or slower --- End quote --- Yes, this would definitely be fine. Anything I have that is over 3 kV at least *should* be a constant voltage. --- Quote from: shapirus on March 06, 2024, 08:23:10 pm ---FWIW, as an example, here's what I am able to capture with a Rigol DHO804 tricked into thinking that it's a DHO924. Cost $342.16 at the time of purchase, but I did use some Aliexpress sale coupons active at that time. --- End quote --- Thanks, this is interesting . . . I am not sure what to make of the budget vs. quality brand debate for this particular purchase. Depending on what you read, brands like Rigol are either a great value and pretty decent to use for anything that doesn't require critical calibration/certification, or are lousy, buggy, and failure-prone pieces of junk with terrible UI. Seems like there's a missing middle for my part of the market, which I know is true for lots of sectors (microscopes come to mind). --- Quote from: blackdog on March 06, 2024, 08:40:00 pm ---Hi, Good pulse response is not possible with passive probes. I have several 500MHz probes and none of them have as few abberations as a good coax connection. Coax type If possible, then always use good 50 Ohm coax, normal RG58 is not good enough for correct pulse response. Bandwidth I am thinking more of a 500MHz model scope with at least 2GHz sample frequency. My 2 cents :-) Kind regards, Bram --- End quote --- The multiplier pulses I would always be measuring with a coax connection directly to the scope, but maybe I should be thinking more carefully about how I split the signal when I need to do this with the other electronics still attached. |
| tautech:
--- Quote from: tggzzz on March 06, 2024, 09:00:48 pm --- --- Quote from: tautech on March 06, 2024, 08:36:39 pm --- --- Quote from: tggzzz on March 06, 2024, 08:31:22 pm --- --- Quote from: tautech on March 06, 2024, 07:58:27 pm ---39kV 1000:1 2pF 50 MHz 900M \$\Omega\$ HVP-39pro fits the bill. --- End quote --- Make sure the voltage vs frequency derating curve is acceptable :) --- End quote --- OP states: like kHz or slower --- End quote --- Yes. So? --- End quote --- No derating @1kHz. :P From the manual....easier than copying the graph: 39KV:1KHz /20KV:10KHz /5KV:100Hz /300V:100MHz |
| tggzzz:
--- Quote from: blackdog on March 06, 2024, 08:40:00 pm ---Hi, Good pulse response is not possible with passive probes. I have several 500MHz probes and none of them have as few abberations as a good coax connection. Coax type If possible, then always use good 50 Ohm coax, normal RG58 is not good enough for correct pulse response. Bandwidth I am thinking more of a 500MHz model scope with at least 2GHz sample frequency. My 2 cents :-) Kind regards, Bram --- End quote --- Have you used a resistive divider probe, a.k.a. a Z0 probe. Passive, multi GHz. If the source impedance is 450ohm, just connect the source directly to a 50ohm input and you have a *10 probe (950ohm *20 probe, etc). With low end scopes, make sure it is a real 50ohm input. Just putting a 50ohm resistor in parallel with a 15pF capacitor is inadequate. Use a pad if necessary. |
| bdunham7:
--- Quote from: stephencox on March 06, 2024, 09:07:35 pm --- Depending on what you read, brands like Rigol are either a great value and pretty decent to use for anything that doesn't require critical calibration/certification, or are lousy, buggy, and failure-prone pieces of junk with terrible UI. Seems like there's a missing middle for my part of the market, which I know is true for lots of sectors (microscopes come to mind). --- End quote --- Both can be true even for a particular model depending on what the user needs and how they use it. The 'missing middle' is actually there in the mid-to-higher end offerings of the B-brands (Rigol, Siglent, GW Instek) and if you just skip the entry-level stuff trying to compete in the $500 price space you'll avoid most of the commonly complained about issues. If you want to spend less than $500 for what is often a fairly capable instrument, you'll just have to put up with some issues. --- Quote ---The multiplier pulses I would always be measuring with a coax connection directly to the scope, but maybe I should be thinking more carefully about how I split the signal when I need to do this with the other electronics still attached. --- End quote --- Then be aware that a lot of the lower priced scopes do not have 50-ohm inputs, which is really a necessity for what you are describing with or without probes being used. |
| tautech:
--- Quote from: stephencox on March 06, 2024, 05:00:33 pm ---I work with electron multipliers and need to be able to look at 10–1000 mV pulses with a rise time of 1.5–3 ns and a total pulse width of ~20 ns. --- End quote --- Hardly challenging with a modern DSO...... 1kHz rate 20mV 20ns pulse with 2ns edges ex SDG6022X AWG. 100 MHz DSO with BNC connection..... |
| Navigation |
| Message Index |
| Next page |
| Previous page |