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View Full Version : OT: New to me oscilloscope... not bad



J Tiers
12-07-2014, 06:46 PM
I have been lusting after a Tektronix THS series 'scope for a while.... They are quite nice, 100mHz or better, isolated inputs, lots of triggering modes, storage (digital 'scope), battery power, internal DMM etc. We have several at work, and they are very nice to use.

Looking for other stuff (Fluke 41b) , I found on Craig's list, a Fluke "Scopemeter". I almost passed by it, since I recall those as being somewhat clumsy 10 mHz basic digital 'scopes.

Not any more. This model (196b) is 100 MHz, has isolated inputs, has almost as much triggering and other digital goodies as the tek units, built-in DMM, lots MORE waveform storage, basically 85% + of the Tek features, everything needed, for in this case, at or less than half the price used. The Tek ones go for $750 to $1100 easily.

So I nabbed it. No need to wait for the Tek unit now.


http://img.photobucket.com/albums/0803/jstanley/machines/misc/Fluke196b_zpsf41fdb7c.jpg (http://smg.photobucket.com/user/jstanley/media/machines/misc/Fluke196b_zpsf41fdb7c.jpg.html)

torchroadster
12-07-2014, 07:21 PM
Congratulations. In my experience Fluke is good stuff!

PStechPaul
12-07-2014, 08:27 PM
I am not a big fan of Tektronix, and prefer HP (now Agilent - and maybe not as good), but the newer Fluke scope-meters are pretty good. The older ones were heavy and bulky, the screen was hard to read, and the batteries didn't seem to hold a charge very well. The place where I work (ETI (http://www.etiinc.com)) calibrates and services multimeters and other instruments, and they have a fairly new Fluke scope-meter, but I couldn't figure out how to set up the cursors and perform waveform measurements. I discovered that it was a lesser model that didn't have these features, and it was very likely just a case of disabling that portion of the firmware (and omitting a few buttons), and not a costly difference in hardware. The manual was the same for both versions, but after looking closely it was apparent that the cursors and associated measurement functions applied only to the better model, which was distinguishable only by a different letter or number and of course the additional keys.

J Tiers
12-07-2014, 08:49 PM
I've never liked the HP triggering from their analog stuff. No experience with the digital. The Tek THS are good portable 'scopes.

The guy threw in an isolated variable AC power supply (Tenma, but acceptable) with the deal as a sweetener. Also nice to have, although I had a workaround already.

Oh, yeah, forgot to mention this model has all the cursors etc, T and 1/T measurements, trigger on pulse widths over/under "X", pretty much all the stuff I use on the Tek units. And for half the price, with Cat III isolation, I'm pretty happy.

There is another model which is more the same size as an 87V meter, that one has fewer functions.

Might need to replace the battery sometime, it seems like it hasn't been given the "refresh" treatment for a while (it is NimH), and may be reduced in capacity.

darryl
12-08-2014, 02:28 AM
I've wanted a portable scope for some time, but haven't done much in electronics lately. I can see the time coming where I'll need a working scope again, and a portable sure would be nice. The old B+K still works, sort of- but it's only 15 meg, and the old Hickok 1805- yikes! Fire that up and wait while 102 tubes warm up, then try to find the trace-

Winter's coming, so maybe I should fire that thing up and see what it can do.

macona
12-08-2014, 03:23 AM
I like the older CRT based Tek digial scopes. I have a TDS-340A (100mhz) and it is pretty nice, especially since they sell for about $100 to $150 used. Cant beat that. At work I use one of the color versions with the crt and lcd shutter, something like a TDS 560. A friend picked up a TDS prototype from the Tek store, goes to 3ghz, for a couple hundred. Self test says they is something wrong but is seems to work right.

MrFluffy
12-08-2014, 03:34 AM
Nice, I always end up with a very non portable scope I have balanced on something when I need one round the shop, good find!
Noticed this, fluke meters seem very hacked on, maybe its because the featuresets are locked off in firmware, or maybe its the usual audience for people who buy them. There are other pieces of test kit which do the same which the firmwares have been broken on to let you reflash them to the full feature set and get the topline functions for baseline money. Noticed this, handy if you need to do the same :-
http://areciv.com/blog/2013/11/fluke-scopemeter-optical-interface/

PStechPaul
12-08-2014, 04:22 AM
My workhorse scope is a Hitachi VC-6035 storage scope I bought around 1989 in preference to the Tek scopes of that era which I could have purchased at cost from the company I had worked for (EIL). The Tek equivalents had a very klunky user interface and the Hitachi performed well on a comparison test jig that the Tek rep had. I paid around $2000 for it. It has served me well for the past 25 years. Recently I accidentally knocked a full can of beer on it and it didn't do it much good, but I took it apart as far as possible without major surgery and cleaned it up, and it is back to working well, although some of the selector switches seem a bit "sticky".

My previous scope was an HP 130A, and I still have it, although it has not worked since about 1983. I got it from my father when it was declared BER after his place of business was flooded during Hurricane Agnes, and I was able to clean out the mud and restore it to operation. It has a special high speed blue phosphor designed for photography. It's only about 300 kHz bandwidth but is a good high sensitivity lab grade scope, and of historical significance: http://www.hpmemory.org/wa_pages/wall_a_page_12.htm

http://www.hpmemory.org/pict/wall_a/130a_left.jpg http://www.hpmemory.org/pict/wall_a/anim/122a_q90/27.jpg

Before that, my father gave me a vintage 1943 Triumph Oscilloscope (with optional "Wobbulator"): http://www.antiqueradio.org/trium01.htm

http://www.antiqueradio.org/art/trium01.jpg http://www.antiqueradio.org/art/trium02.jpg

I totally took it apart, cleaned it, and rewired it, and also replaced the old capacitors. I gave it away because my father didn't like "old junk" lying around. Now I keep everything and am inundated with piles of old "junk", but I like having it around.

J Tiers
12-08-2014, 08:25 AM
Hah!

I had a 130A a LOOONG time ago. If it's the same one I think it is. It was 300kHz, high sensitivity differential input capability, good for audio and biological work. Had an Eico once, also, still have kicking around an AN-105A huge tube-based unit with delay sweep plug-in. And a couple 453, a Tek/Telequipment, etc.

This one will be a big improvement. After using the portable THS 720 and 730 units, I am totally spoiled and hate having to use analog scopes, although I fully intend to keep at least one.

EddyCurr
12-08-2014, 11:33 AM
Very nice acquisition, J Tiers.

I am impressed how the ratio of display-size/case-size
for your oscilloscope approaches 1:1. Mind, I looked
up one of Fluke's booklets on the 196B and noticed it
is 2002. No doubt, the 2015 models have even
bigger displays in more compact cases.

I have a pair of 2-Ch dual-trace 50MHz analog lugables
I purchased some years ago (Tek 2225).

.

J Tiers
12-08-2014, 09:49 PM
I did find the downfall relative to the Tek. The way the trace expansion/zoom is handled is not as nice. It may be a sampling issue, but while there is a selectable expansion zoom, it is quite a bit cruder than the fixed (and larger) expansion/zoom of the Tek.

To be fair, it is a lot more like some of the other Tek scopes, just not like the THS720/730 units.

EDIT:

This turns out NOT TO BE TRUE, actually. It is settable, and I fixed it. Much better now.

Turns out that "glitch detect" mode instead of giving more detail, actually seems to give less, producing an "envelope display" which does not zoom well. When set to have glitch detect "off", it actually gives MORE details than the Tek units. And, there is the capability to give a lot of different DMM type readings simultaneously with the 'scope display.

Pics later.

mickeyf
12-08-2014, 10:02 PM
Ancient scopes, eh? I just sold an Eico and a Dumont that I finally admitted I was never going to have the time to fix up. I'm happy to have a tiny bit more space. The guy who bought them has an amazing collection. (https://www.flickr.com/photos/keithgreenhalgh/) The Dumont is currently featured prominently.

wendtmk
12-09-2014, 08:21 AM
I'm pretty happy with my Tek 7623, 7854, 7603, 7904, SC502, SC503, SC504 and HP something or other 100 MHz storage scope.

I don't think I have enough scopes yet though. ;)

Mark

hoof
12-09-2014, 11:14 AM
Thats a real nice find, I have a Tek PS-222, power scout. Really like it, just 10mhz, portable CRT with vector graphics and storage. It still works with the wall wart. Really wish I knew where I could get a battery for it.

J Tiers
12-09-2014, 08:16 PM
So, the bad zoom function turns out to be just a non-intuitive way the controls operate. Turning OFF "glitch detection" gives a much finer grained and more detailed view.

So here are two similar traces, showing the difference.

This is what you get with the detection "on". I don't know what it does besides mess up the display, possibly it will show you a better contrast of "average" waveform and any anomalous waveform exceeding the envelope. I'll check it out just to be sure I am not missing anything. Might even read the manual (Fluke puts manuals and service info, including schematics on-line).
http://img.photobucket.com/albums/0803/jstanley/machines/misc/fluke196bglitchdetectlowerres_zpsd11f7a24.jpg (http://smg.photobucket.com/user/jstanley/media/machines/misc/fluke196bglitchdetectlowerres_zpsd11f7a24.jpg.html )

This is what the 'scope gives if you do NOT have the "glitch detection" on
http://img.photobucket.com/albums/0803/jstanley/machines/misc/fluke196bhires_zps6092b392.jpg (http://smg.photobucket.com/user/jstanley/media/machines/misc/fluke196bhires_zps6092b392.jpg.html)

And, I discovered a large amount of measurements which can be made on the displayed waveform, two at a time. The duty and PWM volts functions look particularly useful for many SMPS and VFD, class-D etc purposes. Any headings with "..." after them have sub-menus.
http://img.photobucket.com/albums/0803/jstanley/machines/misc/fluke196bscopereadingoptions_zpse91fd22d.jpg (http://smg.photobucket.com/user/jstanley/media/machines/misc/fluke196bscopereadingoptions_zpse91fd22d.jpg.html)

I am giving this 'scope a definite "recommended" rating for anyone wanting a nice digital 'scope.

The newer 196C version has a color display, FFT capability, and other useful things as well. But they charge a *LOT* for it, and a used 196b is quite acceptable at a few hundred bucks as opposed to the new price.

macona
12-10-2014, 03:47 AM
While on the subject of scopes, VintageTek, a local Tek museum, has some really neat videos of some of the making of their products. http://www.vintagetek.org/video-gallery/ The crt making videos are very interesting.

I have a lot of old Tek tools too, that laser welder I have came from them as well as my CNC mill. They are literally walking distance from my house.

Tek in it's day was something else. They made almost all their own parts for everything in the scopes, all their own screws, knobs, and even the CRTs. They spun off and actually encouraged employees to go off and start their own businesses to provide parts for them. Triquint and Planar are just a couple companies that were spun off.

Iceberg86300
12-10-2014, 04:37 AM
Wow do I love Google!

http://pictureperfecthtc.com/Googlesearch.jpg

First page of results and it's not even close to current preview.

Nice looking scope. What is the model # on it? Looking for the full # on the back, or UPC if has one.

Don't want to make you hunt through menus to find the software & model, so if it's not on the back don't worry about.

Just looking for what variant it is, looks like there are a few around.

Regards,
Steve

RichR
12-10-2014, 10:06 AM
So, the bad zoom function turns out to be just a non-intuitive way the controls operate. Turning OFF "glitch detection" gives a much finer grained and more detailed view.

So here are two similar traces, showing the difference.

This is what you get with the detection "on". I don't know what it does besides mess up the display, possibly it will show you a better contrast of "average" waveform and any anomalous waveform exceeding the envelope. I'll check it out just to be sure I am not missing anything. Might even read the manual (Fluke puts manuals and service info, including schematics on-line).
http://img.photobucket.com/albums/0803/jstanley/machines/misc/fluke196bglitchdetectlowerres_zpsd11f7a24.jpg (http://smg.photobucket.com/user/jstanley/media/machines/misc/fluke196bglitchdetectlowerres_zpsd11f7a24.jpg.html )


What you see in the "messed up display" are glitches in the waveform. Glitch detection is typically (though not exclusively) used when looking
at digital waveforms. A digital scope (which this is) takes samples of your waveform at evenly spaced intervals in time and then reconstructs
those readings on the display. You can see what the waveform is doing at each of those sample intervals but not what is happening in between
them. What glitch detection does is place a marker on the displayed waveform if what you are measuring moves outside a threshold between
samples.

lakeside53
12-10-2014, 11:29 AM
The best scope I had was a 200mhz 4 channel Philips. It was EITHER analog and digital at the press of a button... Real good for seeing the effects of digital sampling on some waveforms. Has a ton of features, most of which I never used :)

J Tiers
12-10-2014, 07:10 PM
What you see in the "messed up display" are glitches in the waveform.

The way it behaves is that it appears to show an overlaid waveform, possibly the sum of several past ones, somewhat smoothed. It appears to be the sum of all HF noise, smoothed. That is implied, sorta stated, in the manual.

It may be showing more input data, but it does so in a way that is non-useful to me, as it seems to simply provide an equivalent to a low sample rate coarse display. Definitely counter-intuitive, and non-useful.

If it shows "glitches", the result is ALL glitches and no data, if you see my point..... It would be fine if it showed an envelope of the waveform, and glithes outside of that.

Maybe I will check it out by inserting glitches on a waveform and seeing what results. If that is reasonable, I will see the point of the mode. Otherwise it seems to be lost on me, as more info is resulting in less data as it is.

tc429
12-23-2014, 12:37 AM
we have a scopemeter and a power analyzer- Fluke makes great stuff, but for some reason the power supplies on these scopes seem to be flaky. the one on the scopemeter was replaced several times, the one on the power quality meter seems to be getting iffy...soometimes it dont want to turn on, battery packs dont seem to hold up either...the menus on the fluke power analyzer are not real intuitive either, every time we get it out i gotta fumble with it to set it up...


just got a neat toy a couple weeks ago, search 'Saleae' on ebay, you can get 8 channel logic analyzers for llike 15 bucks, record 8 channels long as you want on your computer thru USB. really a cool little thing for low voltage stuff.

J Tiers
12-23-2014, 08:34 AM
This one is apparently fine, the battery works fine, although after sitting unused by the P.O., I could usefully replace it.

We have 4 Tek THS720/730 series scopes, and of those, ONLY ONE has a functional battery and internal charger. The others refuse to charge their batteries, and in some cases will not work from a battery no matter what. The external chargers mostly do work.

Mike Nash
12-23-2014, 08:41 AM
Yeah, Fluke makes great stuff except...they don't really. It's pretty hard to be impressed when the power supplies and batteries are bad (or take 14 hours to charge), or they eat disposables weekly. Or you miss the "event" because it took too long to get through the ridiculous menus. Or the meter shut off while you are using it.

Maybe if you drop the big, big bucks, maybe, but Fluke is just a name that people seem to love.

BTW I have a Kenwood car radio that ranks right up there in the user friendly ratings too.

Iceberg86300
12-23-2014, 09:03 AM
What's the chemistry on the fluke and tek batteries?

Regards,
Steve

J Tiers
12-23-2014, 08:55 PM
The tek seem to be NiCd, the Fluke uses NimH.


Mike N:
The menus seem very fast on the scopemeter, and you have direct access to each channel, unlike the Tek where you choose a channel and then use a single set of buttons to work with the chosen one. I had it in to work, and the main comment was that it was a lot faster to navigate than the Tek 720/730.

This battery has been abused, but it is still good for a couple hours. Charges reasonably fast. And the overnight battery refresh" cycle seems to do quite a bit of good as well.

I have not had your bad experiences with Fluke. The only items with a shutoff issue are our 3 Fluke 41B volt/amp/watt meter units, and a couple newer 'tong" meters. Those DO shut off aggressively, but the real problem ones are the two tong meters (AC/DC volt/amp meters, maybe #322??)

Mike Nash
12-24-2014, 08:45 AM
I have a Fluke 123, so much less expensive than J Tiers's, but not cheap by any means. Battery is Ni-Cd. It really is poorly implemented.

Internal Battery Pack BP120 (Fluke 123):
Battery Power Rechargeable Ni-Cd 4.8V
Operating Time 4 hours with bright backlight
4.25 hours with dimmed backlight
Charging Time 5 hours with test tool off
40 hours with test tool on
9 ... 14 hours with refresh cycle

Get this firmware upgrade note:

Battery refresh time changed from 12 to 19 hours to reflect the real situation (V2.02)

Battery refresh has to be done regularly or you have no idea what the battery state is. While doing a refresh it simply turns off the display. If you come back to check on it and turn it back on before it is done, you have to start all over. There is NO indication it has completed either.

Switching from standard sweep to roll mode is under the scope menu, not anything to do with timebase. The whole thing might be intuitive to someone who designs for Microsoft or Google, but not for someone coming from the CRT world of old (with lots of real switches!).

It's also a pretty expensive option to get a line sync adapter without which it makes SCR DC drive troubleshooting a royal pain.

All for only $1500.

I'm glad you like yours Jerry. I also realize it's not a 123.

And ringing out panel wiring with an auto-off meter can be frustrating at best.

And what about the teeny-tiny m and M for milli and Mega that Fluke loves to use? Couple that with auto-ranging.

I don't use a Fluke meter but I'm currently stuck with their scope . My nearly unused Fluke IR temp gun lost it's laser early on. No, I don't like Fluke thanks.

We tried Agilent LCD scopes initially, GACK! The menu buttons wouldn't even respond if the ground clip was connected to a VFD. PWM looked like a kid with a crayon in a car on a bumpy road - no idea what was happening.

J Tiers
12-24-2014, 03:48 PM
All for only $1500.

I'm glad you like yours Jerry. I also realize it's not a 123.


Well, for $1500, I'd be annoyed too.

Luckily I paid about a quarter of that, so I am getting into the territory where it's good if it shows a trace.....

I looked at the (very poor) manual for the 123, and it seems to DO a lot, but it also seems to give up ease of use to get the slimmer size. The extra width on this one allows a considerably nicer set of buttons, I think.

Fluke meters, in general, are pretty nice, and they are also a standard, as well as being unlikely to fireball in your hand on higher voltages. But I can understand your overall displeasure, according to the issues you describe. And I DO agree on newer meters often having a too-short auto-off delay.

alanganes
12-24-2014, 04:16 PM
And what about the teeny-tiny m and M for milli and Mega that Fluke loves to use? Couple that with auto-ranging.



I generally like the Fluke meters I have, but have to admit I dislike the accursed tiny m's on the display. Almost got bitten my this just last week. Cost me about 30 minutes of rechecking measurements. Could have been much worse had we not caught it when we did.