Quote:
Originally Posted by Skywave
Quote:
Originally Posted by Craig Sawyers
But - since you aren't going to be really electrically stressing this probe, why not pay £10 - £20 and buy a Chinese Tek rip-off?
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Tried that - twice. The performance on both counts was absolutely dreadful!  Just two more examples of "What you get is what you pay for it".
Al. |
Well, using a 50 or 75 ohm coax will probably do no better than 10 or 20MHz.
If you need something approaching the 300MHz bandwidth of your scope, the only sensibly priced pukka option is an old P6009, which is good for about 200MHz. The odd NOS one crops up (I have one myself). About $50 to $80 plus shipping from the US.
The only other traditional resistive divider probes are the P5100 and P5100A, but those are still stupid money.
But you might consider a Z0 probe. These can be made in a roll-your-own and good to 1GHz. Although the input resistance might seem weedy at 1k to 5k (depending on attenuation), it hardly changes at all with frequency. Whereas a conventional probe has a falling impedance with frequency - at 100MHz such a probe, even with only 2pF input will look like j800 ohms, whereas a Z0 probe still looks substantially resistive.
Roll your own plans here
http://emcesd.com/1ghzprob.htm