Tektronix P6021 current probe use ? - Page 1
Forum section: electronics / testgear

author: ez24
author_rank: Super Contributor
timestamp: July 16, 2016, 09:51:04 pm
content: HiI just got a new (yes I mean NOS 10 hours) Tektronix 465B and a P6021 AC 125 turns current probe came with it (see pic)Can this be used with the scope (on YT it seems it is used on something else, maybe amp)If yes then what can be done with it - I mean what practical use can it be used for with just the scope? What does the 125 turns mean (125 turns of wire?) or for me to turn around 125 times before I use it?Funny thing is is has an arrow sign on it with a +- marks on the head?Is there a simple test I could do with it?thanksEdit - According to the manual, it can be used with the scope. Unfortunately for me, the manual is written for someone who knows what it is.I wonder if it is for some special industry. Maybe it would tell me why someone bought the scope.Now I am reading thishttp://www.emcesd.com/pdf/iprobe98.pdf

author: David Hess
author_rank: Super Contributor
timestamp: July 16, 2016, 10:14:25 pm
content: It is a high frequency, 60 MHz, current probe suitable for switching power supply design and similar applications. The markings show the conventional direction of current flow for a positive output.See that little bar below the CRT on your NoS 465B? Clamp the probe to it, set the passive termination to 10mA/mV, and you should be able to monitor the 30mA peak-to-peak current through the probe compensation output; that is what it is there for. The waveform will look slightly trapezoidal because of the probe's low frequency cutoff.Assuming the probe works since they are pretty fragile, it is worth more than your NoS 465B. To improve the probe's performance, you can pick up a Tektronix type 134 current probe amplifier.

author: ez24
author_rank: Super Contributor
timestamp: July 16, 2016, 10:32:26 pm
content: Quote from: David Hess on July 16, 2016, 10:14:25 pmThanks - now I am trying to figure out what is on the audio tape (cassette) since I do not have a player.

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2016, 10:35:23 pm
content: Wow ez you scored, these are worth $3K new.I have 2, one with the terminator like yours and the other with a 134 amp.As David says they are a 60 MHz current probe but for AC only, use it on DC and you'll bugger it.From the manual:Table 3: Maximum ratingsCharacteristic InformationMaximum continuous (CW) current Refer to Figure 3 for frequency derating curves2 mA/mV 5 Ap-p sine wave between 1.2 kHz and 5 MHz10 mA/mV15 Ap-p sine wave between 300 Hz and 5 MHzMaximum Pulse Current 250 A peak, not to exceed 500(A · s) or 5 ARMS. An(A · s) product greater than 500(A · s) reducesprobe output to zero due to core saturationMaximum working input voltage(uninsulated conductors)300 VAC or VDC, CAT I, and 600 Vpk limited to<10 ms and <25% duty factor.Manual attached.436 Kb

author: ez24
author_rank: Super Contributor
timestamp: July 16, 2016, 10:53:28 pm
content: Quote from: tautech on July 16, 2016, 10:35:23 pmWow - I packed it away - maybe someday I will learn how to use itthanks

author: tautech
author_rank: Super Contributor
timestamp: July 16, 2016, 11:19:08 pm
content: Quote from: ez24 on July 16, 2016, 10:53:28 pmWhen coupled to a CRO they do take a bit of getting your head around, but just remember they're only converting amps to volts that is displayed on the screen from which you can then determine amplitude and frequency.The probe cal loop on your 465B is the best way to become familiar with it, read the 465 manual for the current spec the probe cal loop provides and adjust scope settings until you see the equivalent current on the screen. Hint; there are some "on the fly and in your head" calcs that need be made for it all to make sense.Probe cal outputs are always a great sanity check.Use of these current probes is much simpler on a DSO where input attenuations and measurement types can be set to have the OSD in amps and at the correct attenuation.