For sale: HP 1152A Active scope probe - 2.4GHz bandwidth - 0.7 pF - Page 1
Forum section: electronics / general

author: tnt
author_rank: Regular Contributor
timestamp: June 26, 2011, 10:55:36 pm
content: Hi,I have two of the scope probes and only really need one.I modified one of them to work with the newer 3000-X agilent scope and it seems to work great. The mod only involves the 'comp box' and not the high speed probe head.Depending on what you prefer I can sell either:- A unmodified probe (exactly as I got it) that has no visible tampering / damage (and still has the warranty seal) but that I can't test (because not supported by the 3000-X)- A modded probe that I can test and that will work in the 3000-X (and any other).Both have most of the accessories (not all but close) and spare tips.I'l try to post some shot of the probes and accessories and of the one working with the 3000-X.Make offer (here or in PM).Cheers,Sylvain

author: ErnieEngineer
author_rank: Contributor
timestamp: July 23, 2011, 07:42:50 am
content: Hey, how did you get the smartprobe to work with your scope? whats the hack?

author: tnt
author_rank: Regular Contributor
timestamp: July 23, 2011, 10:16:49 am
content: There are several things:IdentificationOld probes identified by a specific resistor value between a pin and ground. Now, they all have the same resistor value but have an I2C EEPROM for the probe specs. So you need to replace the ID resistor and add an I2C EEPROM.Power supplyMore advanced scope have a variable symmetric power supply sent to the probe. Between +-3V to +-6V depending on another set resistor. The 3000-X doesn't have this supply and only sent a fixed +- 5V value, which is the value required by all new modern probes. Unfortunately the 1152A wants 4V so if you just try to plug it, you send 20% too much voltage to the delicate FET amplifier in the probe ...Solution is to cut this 5V direct path and insert a LDO + filtering in the path.Pictures in attachement. The orange stuff is a kapton sleeve I made to ensure no shorts.Cheers,Sylvain

author: ErnieEngineer
author_rank: Contributor
timestamp: July 24, 2011, 03:54:47 am
content: thanks tnt. you cam thru for me again! how did you figure out the probes use a chip id? did you have a newer probe to mess around with?never mind. i see you posed all about this in the projects section

author: tnt
author_rank: Regular Contributor
timestamp: July 24, 2011, 10:35:53 pm
content: Do you have a 1152A ?

author: ErnieEngineer
author_rank: Contributor
timestamp: July 25, 2011, 12:00:34 am
content: I actually bought a 1142A power box and an 1144a probe that connects to the power box. I also got the 1141A differential probe which connects to the same power box. I also got the 1153A differential smart probe (same as the 1153A but with smartprobe). I just ordered an infinivision 3000 series and will get it in a day. I am practically broke now so I cant buy your probe :-(.I remember you measured a usb signal. How did you do that without a differential probe? I believe usb is differential.

author: tnt
author_rank: Regular Contributor
timestamp: July 25, 2011, 08:02:39 am
content: I just measured one of the signal, you can still see the USB pattern with just one wire.I couldn't find a cheap differential probe ... I'd like one with ~500MHz bw.