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Products => Test Equipment => Topic started by: grayduster on February 28, 2018, 02:06:21 pm

Title: Tektronix 485 budget/second hand probes?
Post by: grayduster on February 28, 2018, 02:06:21 pm
Hi,

Having picked up a nice second hand Tek 485 350MHz scope (unfortunately without the probes), i'm now wondering which Tek probes would be good replacements - it seems the original models are just a tad rare!

Originals (as recommended in the manual) are P6056, P6057, P6053A and the P6201 FET probe:

(https://i.imgur.com/psIMtGA.png)

I can obviously just grab some generiprobes from Ebay like (https://www.ebay.co.uk/itm/4-Four-New-100MHZ-Oscilloscope-clip-probes-for-HP-Tektronix-Hitachi/161074468643?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 (https://www.ebay.co.uk/itm/4-Four-New-100MHZ-Oscilloscope-clip-probes-for-HP-Tektronix-Hitachi/161074468643?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649)), but thought I'd ask people's recommendations (particularly if you have a Tek 485 sitting around!).

Thanks for reading!
Title: Re: Tektronix 485 budget/second hand probes?
Post by: tggzzz on February 28, 2018, 03:04:46 pm
485s are indeed nice scopes, but you do need good probes - and good probing technique.

You will note your image shows there are three broad classes of probes in your image: FET, "low" impedance Z0 resistive divider probes, and traditional "high" impedance *10 probes. It is worth understanding the characteristics of each class, and when they are applicable.

Once you have decided which class of probe suits your applications and wallet, to a first approximation they are all much of a muchness.

It is possible to DIY your own Z0 and FET probes, but the traditional *10 "high" impedance probes are tricky - and are a lower impedance than "low" impedance Z0 probes!

Some resources about probe theory, use, safety and DIY are at https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/
Title: Re: Tektronix 485 budget/second hand probes?
Post by: Electro Detective on March 01, 2018, 12:00:09 am
Just a thought, if you don't need the Teks full 350mhz bandwidth just yet, and want to jump on board and use the scope,

some of the 100, 200 and 300mhz DSO probes that work with the Rigol, Siglents etc go pretty cheap on Ebay

You can always flog them off later once some Tek probes come your way