DIYHiFi.org

Hello All,

I'm finally getting around to purchasing a scope, which will be for personal use only. As such, I'd like to keep it under $1.5K. A few questions:

1. Is 100MHz adequate for most digital applications in audio DIY? As of now, I want to measure a 24MHz signal...

2. How often would I actually use 4 channels? Could anyone describe common applications when this addition would come in handy?

3. Is TEK the only brand I should be looking at? BTW, I'm considering a newer model, so it would have to be digital (analog scopes are no longer made, correct?)...

Thanks,
Bryan

Well.............my old analogue 'scope died a few months ago, and I picked up a used (obviously) Tek 465. I wanted to get a 475, but could not find any locally.

The 466, 475, 485 'scopes are hard to beat. Even as old as they are. I know there are good deals on eBay, but I needed one, and that day, so I bought what I could locally.

100 MHz is the minimum I would get.

As for the new Tek 'scopes...........

Never used any, but a lot of guys I used to work with who had them there, were not fond of them. May be just a cranky old fart thing, but they all preferred the old ones.

Mind you, the new ones can do things the old ones didn't. But unless you pay $$$$$$, you don't get the neat features, like jitter analysis. Having said that, the new ones make capturing a specific part of a waveform for analysis something worth having.

If this is going to be the first 'scope you buy........get an oldie but goodie, and save your $$$$ for a fancy one when you are convinced you need it.

Jocko

Get one from eBay. Buy one that is mint or guaranteed in perfect working order (they cost a little more). But still, for $100 or $200 you can get a really good 100MHz scope.

And yes, stick with Tek or another well respected brand (during that era).

Go to business and industrial -> test equipment -> oscilloscopes. Browse for awhile until you find something that catches your eye. Eventually you will know all of the models and makes. At this point, I pretty much know what I need before I even start searching. Must have bought at least 50 pieces of test equipment from eBay in the past 7 years...

jh

_________________
Jim Hagerman

Thanks for the suggestions. A few more questions...

Any opinions on 2 vs. 4 channel?

Do the digital scopes require calibration?

How long is the average analog calibration good for? How long will a digital one last?

Thanks,
Bryan

Are you going to spend $1,5k... I think you will get quite a nice scope for those moneys!

Tek scopes, avoid first generation TDSxxxxA series, it should better be TDSxxxxB, or -C series.

LeCroy is another IMO very nice scope, have used one from the 93xx series who entered the market around middle 90's, look for 93xx series.
As LeCroy skipped the service commitment for the 93xx series just for a while ago I myself hope they will fall in price on the used market soon.

For such an amount of money you mentioned you will get a nice 4 ch 400 MHz DSO from eBay, 4 ch any time, it makes life so much easier in many cases you want to follow several signals around a circuit and get the "whole picture" what's moving inside you circuit.

Cheers michael

EDIT: I meant TDSxxxA, -B & -C (Note >>> triple-X, NOT quad-X!!)

eg. like: TDS500 or TDS700 series ver. B or C.

Cheers Michael

Since you mention it... you say avoid e.g. TDS200. What about the newer (newest?) TDS2012?

BTW, how much should I expect to pay for a calibration? Are there different tests/adjustments that can add to the cost?

Thanks,
Bryan

Hi,

I am about to buy new Agilent (former HP) DSO3062A for home use. It is comparable to Tek TDS2002 but it costs only 1000 US$ even here in Europe. I have a new Agilent DSO6034A (which costs almost 8 times as much) at job and I am most impressed. So I hope that small Agilent turns out to be equally impressive as his big brother.

I can post first impressions after a few days (hopefully).

I have one question though. DSO6034A I have at my job has an interesting feature. It has upgradeable memory (from 2 to 8 Mpts) and logic analyzer. It turns out that all the hardware is already built in and upgrade consists only of appropriate license file for the internal firmware. Considering that all DSO3000 series contains the same digitizer I wonder if also analog part for the whole series (from 60 to 200MHz) is the same and it is only limit in firmware that sets apart different models.

Best regards

Jaka Racman

Hi,

I am about to buy new Agilent (former HP) DSO3062A for home use. It is comparable to Tek TDS2002 but it costs only 1000 US$ even here in Europe. I have a new Agilent DSO6034A (which costs almost 8 times as much) at job and I am most impressed. So I hope that small Agilent turns out to be equally impressive as his big brother.

I can post first impressions after a few days (hopefully).

I have one question though. DSO6034A I have at my job has an interesting feature. It has upgradeable memory (from 2 to 8 Mpts) and logic analyzer. It turns out that all the hardware is already built in and upgrade consists only of appropriate license file for the internal firmware. Considering that all DSO3000 series contains the same digitizer I wonder if also analog part for the whole series (from 60 to 200MHz) is the same and it is only limit in firmware that sets apart different models.

Best regards

Jaka Racman

Please do.

Regards,
Bryan

For analog stuff, I like the 2xxx Tek scopes - I have a 2445 on my bench at home. These have one of the sharpest trace displays Tek ever made. I find it to be my favorite analog scope of all the types I've used. About the only thing to worry about with these is the vertical amplifier chip, which can pop eventually, and replacements are hard to find. Opening it up to install a heatsink on this chip is recommended (problem is common to the 2465 as well). For light use at home in a hobby setting, I don't think it's anything to worry about. For use in a professional setting, I'd look at a 7000 series mainframe, but these are heavy bastards!

Digital-wise, I like the LeCroy stuff a lot. Mostly because of their very thorough measurement features, which are really geared toward accurate numerical analysis. I like their user interface / data presentation and their nice big displays. LeCroy also has generally equipped their stuff with really deep acquisition memories, even their older 93xx series (today's best bargain in used DSOs, I think) commonly have 1Mpt to 4Mpt capture buffers... lots of data to zoom in on and number-crunch against. For $1500, you might find a nice 9354 4 channel 500MHz. Or the 2-channel 9361 with it's faster 2.5GS/s sampling would be a bit less (this is what I own at home). Be sure to look for the high-speed processor option CPU3.

Tek's DSO offerings all seem rather ho-hum to me. Nothing-special displays (small, low contrast, poor sharpness and resolution), small acquisition buffers, and somewhat lacklustre measurement features (yes, they offer the standard measurements, but I don't find them to be impressively functional in any way - they just sorta get the job done to a 'good enough' standard). On the plus side, the Teks are small and lightweight, reliability seems good, and as usual they have the familiar Tek user interface. For the $ Tek DSOs cost, I'm not convinced.

Yokogawa makes some interesting DSOs. I had a chance to play with one briefly, and it seemed like a very nice machine - great specs on paper, too... can't say much more than that, as I have little experience with these.

I don't have any experience with Agilent's current crop of low- and mid-range scopes, but a couple of years back I had an Agilent Infiniium as my primary scope at work. This one was nice to use, and had some good features and a better display than the Teks. It was also faster and had a hell of a lot more buffer depth. Took forever and a day to boot though... ran on windoze (yeeeuk! ). But, it was a very capable scope nonetheless, with a pretty intuitive user interface. I found this surprising, because I'm not fond of older HP scopes at all (disliked their UI). So IMO, HP/Agilent has really improved their product in recent years. I'm keen to hear what Jaka has to say about his new toy...

_________________
- Chad.
__________________________

"Fashion is mistaken for good design; moral fashion is mistaken for good." -- Paul Graham

Back when I had a real job........(yeah, I know....centuries ago), we had some 7000 series stuff. Spent more time at Tek than it did in our lab. Of course, someone else bought it, and they managed to buy the least popular ones they made. Maybe that is a clue.

Jocko

No kidding? Hmm... maybe that's why the 7 series modules are so cheap on ebay? Well the one I used years ago seemed like a nice instrument, anyway ... or at least I thought the 7A22 (?) diff amp in it was pretty slick. I suppose I just assumed that a heavy mainframe like that would be at least as reliable as a portable model. Plus, they seem to have something of a following. But not having lived with one of these monsters on a long-term basis, I defer to Jocko's experience here.

_________________
- Chad.
__________________________

"Fashion is mistaken for good design; moral fashion is mistaken for good." -- Paul Graham

my 7904 and 7313 work very well. the 7313 was 59?.

The nicest scope I ever had was a Tektronix 485.
I sent it back as it had a faulty gain switch.
Absolutely unbelievable allmost all components are socketed......
Apparently a relay had worked it's way out of a socket.