Agilent 1130a input impedance

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I recently picked up an Agilent 1130a probe for a very reasonable price, but without accessories and in " not working " condition. My scope detects the probe fine and touching the input will shows reasonable 60Hz noise.

I was curious if anyone knows what the front end impedance on the amplifier should look like without the probe head attached. All of the references I can find (reasonably) include the heads in the 25k/50k ohm spec. Can I validate the probe is working before spending more on a accessories?

[uncle_bob]

Hi

A picture of what you actually have (and thus also what you are missing) might help a bit.

Bob

[FFFF00]

Hi Bob,

Sorry about the confusion, I am not missing anything from the main probe that connects to the oscilloscope. I've include the stock pictures that coincides with what I have. I just don't have any of the attachable accessories that must be used with the probe.

Thanks!

[uncle_bob]

Hi

There is nothing much you can do to checkout what is shown in the picture. You need a way to cable it into a calibrator output. Since the connectors on the front end of that thing are highly custom ... you have no real choice other than getting a "real HP" head to do the test with. It's simply the issue of having a proper RF path into the device that gets you.

Bob

[FFFF00]

Hi Bob,

I believe the connectors are SMP (or at least SMP compatible), I found reference in one Agilent document. I could push a signal into the probe, but I'm hesitant to do so without knowing what the amp expects. It'd be a shame to kill a working probe.

Thanks!

[uncle_bob]

Hi Bob,

I believe the connectors are SMP (or at least SMP compatible), I found reference in one Agilent document. I could push a signal into the probe, but I'm hesitant to do so without knowing what the amp expects. It'd be a shame to kill a working probe.

Thanks!

Hi

The standard probes are just wires (except for the blocking caps and the attenuators).  A proper calibration will only work (it will only come out flat) with the Agilent test head. While they are "just wires" they are indeed carefully done coax cable wires for calibration ...

Bob

[tesla500]

The probe tips are just (very special and tightly controlled) 25k resistors connected to short bits of coax. You can test the probe by connecting a 25k or similar resistor from a test signal source to the center pin of the connector. There's a little hole for a pin for a ground connection on the probe amp head.

Edit: With the resistor connected to the + input you should see the signal, connected to the - input you should see the same signal inverted.

Here are the probe tips and accessories you want to be looking for on Ebay:

E2675A Differential Browser Kit for InfiniiMax Probes
E2669A InfiniiMax Differential Connectivity Kit
E2668A InfiniiMax Single-ended Connectivity Kit
N5381A InfiniiMax II 12 GHz differential solder-in probe head
N5382A InfiniiMax II 12 GHz differential browser
N5425A 12GHz InfiniiMax differential ZIF probe head
E2677A InfiniiMax 12 GHz differential probe head
N5451A InfiniiMax differential long wire ZIF Tip
E2679A InfiniiMax single-ended solder-in probe head and accessories
E2676A Single-ended browser probe head and accessories
E2678A InfiniiMax single-ended/differential probe head and accessories
N2880A InfiniiMax In-line attenuator kit

Probes themselves:
1130A InfiniiMax 1.5 GHz Probe
1131A InfiniiMax 3.5 GHz Probe
1132A InfiniiMax 5 GHz Probe
1134A InfiniiMax 7 GHz Probe

Here are the search terms you can dump into ebay to find these:

Probes:
(1130A, 1131A, 1132A, 1134A)

Differential
(E2675A, E2669A, N5381A, N5382A, N5425A, E2677A, N5451A, E2678A)

Single Ended
(E2668A, E2679A, E2676A, E2678A)

[FFFF00]

The probe tips are just (very special and tightly controlled) 25k resistors connected to short bits of coax. You can test the probe by connecting a 25k or similar resistor from a test signal source to the center pin of the connector. There's a little hole for a pin for a ground connection on the probe amp head.

Edit: With the resistor connected to the + input you should see the signal, connected to the - input you should see the same signal inverted.

Awesome! That worked great, I was able to get a signal into the probe which looked reasonable. Now to go back to scouring eBay for a reasonably priced probe head. Thank you very much for the compiled list!