Author Topic: New Agilent scopes (Read 382364 times)

oPossum · « **Reply #275 on:** April 10, 2011, 07:31:17 pm »

Signal wire is silver color and measures 186 ohms.
Ground wire is copper and measures 1 ohm.

oPossum · « **Reply #276 on:** April 10, 2011, 07:36:29 pm »

Quote from: tnt on April 10, 2011, 06:50:29 pm

@oPossum: Wow you sacrificed one of the probe. Nice

I wouldn't have done it if I had all 8 leads, but there where only 7. Now there are 6.

Leo Bodnar · « **Reply #277 on:** April 11, 2011, 07:45:29 am »

Here is what came with my MSO-X 3024A:

The length of 300MHz passive analogue probes is 135 cm.

The length of digital probes from socket to the ends of inserts is 165 cm. Does difference create some skew between them?
The resistance of the woven cable is 186 Ohms on the signal wires and 0.3 Ohms on the GND ones.

tnt · « **Reply #278 on:** April 11, 2011, 08:22:27 am »

Well you can plug both to the square wave compensation output of the scope and show us a close up on the transition edge ... and then tell us if there is skew :p

EEVblog · « **Reply #279 on:** April 11, 2011, 08:22:51 am »

Quote from: Leo Bodnar on April 11, 2011, 07:45:29 am

Here is what came with my MSO-X 3024A:

The length of 300MHz passive analogue probes is 135 cm.

The length of digital probes from socket to the ends of inserts is 165 cm. Does difference create some skew between them?
The resistance of the woven cable is 186 Ohms on the signal wires and 0.3 Ohms on the GND ones.

You can adjust the skew on the analog channels. And I think also the same on the digital channels (too lazy to check)

Dave.

ElektroQuark · « **Reply #280 on:** April 11, 2011, 10:24:23 am »

Try with an SCSI Ultra 320 cable instead an IDC.

tnt · « **Reply #281 on:** April 12, 2011, 09:41:22 pm »

A bit of scope pr0n :p

Anyone recognizes what it is ?

I admit, the passive probe dampens the signal quite a bit ... but I still haven't received my active probe.

Leo Bodnar · « **Reply #282 on:** April 12, 2011, 10:17:35 pm »

Some sort of PLL sync preamble and burst of data?

mikeselectricstuff · « **Reply #283 on:** April 12, 2011, 10:33:15 pm »

ECG of Agilent's product manager on discovering that AgilentConfidential_SecureDataTool leaked..?

tesla500 · « **Reply #284 on:** April 12, 2011, 11:47:23 pm »

Quote from: mikeselectricstuff on April 12, 2011, 10:33:15 pm

ECG of Agilent's product manager on discovering that AgilentConfidential_SecureDataTool leaked..?

Hmm, their heartbeat instantly jumped to 233 megabeats per second, settled into a quantum superposition of simultaneous Diastolic and Systolic states, then flatlined, all within 200ns? LOL!!

Is this data transfer to a RAM of some sort? The 233MHz initial waveform like something used for computer memory.

David

mikeselectricstuff · « **Reply #285 on:** April 13, 2011, 12:06:30 am »

Something suffering some major metastability?

bandtank · « **Reply #286 on:** April 13, 2011, 01:57:23 am »

My first reaction was USB high speed, but I'm not sure. It definitely looks like some type of differential signaling with the same header and then a lower frequency 0 or 1. My guess is an enumeration or electrical idle exit packet of some sort, but I really have no idea.

EEVblog · « **Reply #287 on:** April 13, 2011, 04:23:15 am »

Quote from: mikeselectricstuff on April 12, 2011, 10:33:15 pm

ECG of Agilent's product manager on discovering that AgilentConfidential_SecureDataTool leaked..?

*snort*

Dave.

tnt · « **Reply #288 on:** April 13, 2011, 05:06:44 am »

Quote from: bandtank on April 13, 2011, 01:57:23 am

My first reaction was USB high speed, but I'm not sure. It definitely looks like some type of differential signaling with the same header and then a lower frequency 0 or 1. My guess is an enumeration or electrical idle exit packet of some sort, but I really have no idea.

That's right, it's USB hi-speed.
Taken on a USB stick doing nothing, (so just idle or random packets).
But at 240 MHz, the probe impedance looks more like 100 ohm than 10M so the loading is a bit high to see a nice signal.

bandtank · « **Reply #289 on:** April 13, 2011, 05:31:40 am »

Hurray! I figured as much because of the way the waveform is shifted to a common mode of a few hundred mV and then differentially signaled around it at ~240MHz, or at least the packet header is that fast. You can almost see an eye in the middle of the waveform which basically gave it away as being the address of a device hanging off of the bus. I'm curious to see the waveform with your active probe.

Thanks for the fun little challenge.

tnt · « **Reply #290 on:** April 13, 2011, 08:41:53 am »

Quote from: bandtank on April 13, 2011, 05:31:40 am

I'm curious to see the waveform with your active probe.

Yes me too :p
Unfortunately, it's coming by EMS so no real tracking and it's pretty slow.

(I didn't buy it new, those things are insanely expensive and the scope ruined me already :p)

_Sin · « **Reply #291 on:** April 13, 2011, 10:42:31 pm »

I opened up my DSO2004 for a bit of a poke around.

Just a heads-up for anyone who wants to try playing around with JTAG - I think the convenient looking pin-header that Dave highlighted in his tear-down is not, in fact, a JTAG port. At least it doesn't seem to be directly connected to the appropriate CPU pins. Instead, if you want to hook up to the CPU's JTAG interface, there are 8 neatly spaced, slightly larger than typical, VIAs just above the CPU (between it and the flash). Those appear to be hooked up to the JTAG pins, and there are also some resistors/unpopulated-pads which look like they're connected to the config pins on the CPU.

I didn't go to the trouble of actually working out which pin was which, nor what the config pins default to (it's possible you'd need to change the resistors around if you want to enable JTAG), but if you're looking, that's where I'd start...

I didn't explore the JTAG pads over by the ASIC - not sure if they're chained up to the CPU or not, and I suspect the CPU JTAG is of more interest.

However it's late here, and I'm tired, and I wanted to put it back together again and make sure it still works. (It does!)

Rufus · « **Reply #292 on:** April 14, 2011, 01:40:12 am »

Standby power consumption?

I noticed the scope keeps itself warm. Particularly noticeable at the bottom of the storage compartment just above the power supply. I got the impression from the teardown blog it had a real mains on/off switch but it doesn't and some information in the service guide confirms that.

I measured the standby current at 86mA with a non-rms meter and 235v supply, obviously low power factor because it feels like 2 or 3 watts not 20.

Anyone here have the scope and a mains power meter to measure it?

Edit: Thought more about this and it smells of design cock up. Why would you go to the trouble of mounting a switch right next to the mains input and using a long bent plastic actuating rod to bring it to the front panel when all it is doing is switching a control signal to the power supply? I guess the switch they designed it around (possibly the switch in there now) wasn't up to the job so they kludged it and left us with a lot of standby power. The thing idles warmer than my old frequency counter which keeps the whole power supply active for the crystal oven.

EEVblog · « **Reply #293 on:** April 14, 2011, 08:04:49 am »

Quote from: Rufus on April 14, 2011, 01:40:12 am

Standby power consumption?

I noticed the scope keeps itself warm. Particularly noticeable at the bottom of the storage compartment just above the power supply. I got the impression from the teardown blog it had a real mains on/off switch but it doesn't and some information in the service guide confirms that.

I measured the standby current at 86mA with a non-rms meter and 235v supply, obviously low power factor because it feels like 2 or 3 watts not 20.

Well, wadya know!
I just measured the 3000 at 7.8W with my energy meter.
That's nothing short of disgusting!
I didn't even think of measuring it because at first glance it looked like a real mains switch.

Dave.

Leo Bodnar · « **Reply #294 on:** April 14, 2011, 08:09:13 am »

Quote from: EEVblog on April 14, 2011, 08:04:49 am

That's nothing short of disgusting!

This could be design feature that allows for soft start instead of hard power surge typical with full off switch?
Cheers
Leo

hacklordsniper · « **Reply #295 on:** April 14, 2011, 10:34:05 am »

Quote from: Leo Bodnar on April 14, 2011, 08:09:13 am

This could be design feature that allows for soft start instead of hard power surge typical with full off switch?
Cheers
Leo

Like a RIGOL DG1022 (full off switch) which on turn on makes strange hums, display flashes violently then fades with garbage and everytime i turn it on i fear "its dead"

mikeselectricstuff · « **Reply #296 on:** April 14, 2011, 11:29:58 am »

When I first saw the teardown vid I thought the mains switch looked a bit on the small size - maybe this was a late-stage cost-cut, or maybe they ran out of space for a proper switch.
Would be interesting to see some pics of the mains input board - one thing that struck me on the teardown vid is the clearances looked a bit tight around the mains parts. Tere are some SMD parts very close to the connector to the PSU, although these could be the line trigger input circuitry (assuming this scope has a line trigger mode)

Rufus · « **Reply #297 on:** April 14, 2011, 02:57:26 pm »

Quote from: Leo Bodnar on April 14, 2011, 08:09:13 am

This could be design feature that allows for soft start instead of hard power surge typical with full off switch?

The scope's power switch is latching so you can get a 'hard' start switching it on at the plug anyway.

If 'soft' control of power was an original design feature they would have put a push button on the main PCB instead of a cut out for the power switch actuating rod.

The original design intention must have been to switch the mains with the power switch mounted right next to the inlet. Presumably at some late stage they discovered the switch wasn't up to the job and/or they couldn't get a mechanically compatible switch that was. So they reved the filter board so the switch controlled an enable on the output side of the power supply block instead.

Very disappointing the power supply block has such high quiescent power, but, it would not have been a requirement for the original design. Maybe they will rev the power supply block to be less embarrassing in the future.

hacklordsniper · « **Reply #298 on:** April 14, 2011, 04:14:32 pm »

Thats logical thinking Rufus!

I wonder would it maybe be better to buy this scope in a year or so then now, simply to wait for them to remove all possible (hardware) bugs from it?

Leo Bodnar · « **Reply #299 on:** April 14, 2011, 04:18:11 pm »

Quote from: hacklordsniper on April 14, 2011, 04:14:32 pm

I wonder would it maybe be better to buy this scope in a year or so then now, simply to wait for them to remove all possible (hardware) bugs from it?

This depends on what value you put on a year's worth of your life.


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Author Topic: New Agilent scopes (Read 382364 times)

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