Keysight 3000T probe compatibility

[Amazing]

What exactly is the level of compatibility for the Keysight AutoProbe interface?  I've got a new (to me) DSOX 3104T coming soon.  It's a 1GHz scope but only comes with 500MHz probes.  I'd love to be able to pick up some used probes on ebay.  But the official compatibility list in the manual is very limited.

I'm hoping that's just because Keysight doesn't want to recommend discontinued probes, so they can sell new ones.

Does anyone know if the older probes are compatible?  I've been seeing good deals on 1156A probes pop up, but I haven't jumped on any yet.

If there is any risk at all to using older probes then I won't do it.

[Someone]

1156A works on the 3000X happily, if they start locking out older probes for marketing reasons you just modify them to identify as generic probes:
https://www.eevblog.com/forum/testgear/1159a-differential-probe-modupdate/

[Amazing]

Good to know, thanks.  I spent some time reading old threads about probe modification.

It looks like the 3000T will just notify you if you try to pull too much current from the probe port, is that correct?

So it would be pretty hard for a bad probe to kill the scope?

In any case I think I might try powering up the probes before connecting them to the scope, and checking voltages and current draw.

[MarkL]

I've been pretty happy with the combination of the Keysight/Agilent N2744A TekProbe II adapter and used active Tektronix probes on my X3104A.  The adapter allows access to a broad range of Tek probes.  See Keysight probe accessory guide, pg. 29, for the list of supported probes:

  http://literature.cdn.keysight.com/litweb/pdf/5968-8153EN.pdf

Keysight, LeCroy, Rigol (and others?) sell TekProbe adapters so if you move to a different scope manufacturer you don't have to re-buy all your probe types.  And if you want to use your active Tek probe standalone, like on a spectrum analyzer, you can get a Tek 1103 dual probe power supply for $200.

Right now there's an adapter on ebay for $380 and a Tektronix P6245 1.5GHz for $125.

[Someone]

So it would be pretty hard for a bad probe to kill the scope?

Yes, hard to damage the scope (I've seen the message many times, and you get it if you plug in too many probes at once too), but its possible the fixed 5V supplies might damage some probes that are expecting a variable 3-6V supply.

[Keysight DanielBogdanoff]

It looks like the 3000T will just notify you if you try to pull too much current from the probe port, is that correct?

Yes, correct. You'll get an overload indicator and the scope will tell you to remove the probes and reboot. The rule of thumb is that you can use two fully-loaded active probes simultaneously with the 3000T's interface. You can often get away with more depending on what you're doing.

So it would be pretty hard for a bad probe to kill the scope?

I will cautiously say "yes." The protection is generally pretty good, but a broken probe could do some damage (especially to the 50ohm path) depending on the type of probe failure.

In any case I think I might try powering up the probes before connecting them to the scope, and checking voltages and current draw.

For the 3000/5000/6000/7000 Series oscilloscopes, you get at most +-400 mA max current supplied by the scope for all the probes combined. We call it "Autoprobe lite"

For the 4000X/6000X/9000/90000A/S-Series (BNC connection) you get +-200 mA per channel. We call it "Autoprobe I"

For the 90000X/Q/Z (SMA connection) you also get +-200 mA per channel. We call it "Autoprobe II"

Have fun!

[Keysight DanielBogdanoff]

1156A works on the 3000X happily, if they start locking out older probes for marketing reasons you just modify them to identify as generic probes:
https://www.eevblog.com/forum/testgear/1159a-differential-probe-modupdate/

I'd also say that we generally don't lock out probes for marketing reasons, it's more of a QA or manufacturing demand decision.

[MarkL]

For the 3000/5000/6000/7000 Series oscilloscopes, you get at most +-400 mA max current supplied by the scope for all the probes combined. We call it "Autoprobe lite"
...

FWIW, I can get 4x P6245 Tek active probes on a MSO-X3104A using 4x N2744A adapters.

[TheSteve]

1156A works on the 3000X happily, if they start locking out older probes for marketing reasons you just modify them to identify as generic probes:
https://www.eevblog.com/forum/testgear/1159a-differential-probe-modupdate/

I'd also say that we generally don't lock out probes for marketing reasons, it's more of a QA or manufacturing demand decision.

Can tell us why the 1159A isn't supported on the 3000 series?

[Keysight DanielBogdanoff]

I did some asking around, and the 1159A was discontinued around 2003. So, when the 1 GHz 3000 series scopes came out they'd been out of production for a good amount of time. My bet is that is was long enough to not make the cutoff for QA. Modding is most likely your best bet.

[Amazing]

So it would be pretty hard for a bad probe to kill the scope?

I will cautiously say "yes." The protection is generally pretty good, but a broken probe could do some damage (especially to the 50ohm path) depending on the type of probe failure.

Thanks, I will check that the signal output does not exceed the 50 ohm voltage limit.

I can definitely understand how QA for every old probe out there would be a pain.