Which oscilloscope?

[AB8RO]

So here's the scoop. I have an aging Hitachi VC 6045A which is a dual trace 100Mhz quasi digital scope. I mean that its signal path is analog but that it can insert its waveform recorder in the signal path in the digital storage mode. I was thinking about replacing it with a slightly faster scope.

After doing minimal research I thought that I wanted a TEK-2440. This morning I went to look at a 2430 which is the 150Mhz version of the 2440 and man what a nightmare. First, as near as I can tell, the 2430/32/40 are not analog in the same sense that my Hitachi is. The display is always reading the digital sampler. So that is NOT what I want. Beyond that, the thing was just irritating to use, noisy, and too large.

I don't use the digital features very often at all in my scope so good analog capabilities are the primary desire. I do need it from time to time, however, so I do want to be able to take snapshots triggered from external trigger.

I'd like something in the 150 to 350Mhz range that is fairly small, reasonably priced (used), and reliable. I find the built in frequency counter handy, but not essential, and it would be nice to have a similar voltmeter built in, but again, not essential.

What other scopes are primarily analog but have a digital mode?

tnx

[KV1M]

Well, I have a 2430 and I like it.

Does what I need, even for the SDR stuff.

[AB8RO]

Well, I have a 2430 and I like it.

Does what I need, even for the SDR stuff.

I'm sure that when they work, they work fine. I'm not suggesting that it's not a good scope, only that I didn't like it.

[AC0FP]

I have a TDS 210 for everyday use on my bench. Its a real time digital scope with a 1GS/s sample rate, however its only 60 MHz BW, but it is small and light. For anything higher in frequency I use a spectrum analyzer or network analyzer.

Frank:)

[VK2TIL]

There are not many of the kind of 'scope you are seeking and they are getting old.

They were an interim solution until designers came to grips with fully-digital 'scopes.

Whilst it's not the kind of 'scope you are seeking, I use a TDS-320; 100 MHz. The '340 is 200 MHz. They seem to be good buys on ebay.

As ever with Tektronix, the 100 MHz is only the -3 dB limit; mine will trigger until 290 MHz.

The Measurement menu makes it a great instrument; it measures voltages (RMS, P-P & others I never use :) ) period, pulse width etc and displays them as well as the waveform.

I do find that I use spectrum analysers & power meters more than I use the 'scope but it's still an indispensable weapon in the technician's armoury.

[AB8RO]

There are not many of the kind of 'scope you are seeking and they are getting old.

They were an interim solution until designers came to grips with fully-digital 'scopes.


I was afraid of that. I have often found digital scopes less useful than analog scopes in how dirty signals are represented. I've used the newer compact TDS series scopes in the workplace and while I liked many of their features I also found the same irritation with noisy signals. I also did not find the user interface compelling although it's been long enough that I can't remember exactly what it was that I didn't like about them.

How do the TDS series compare with the 2430/2440 series stuff? Has anyone used any of the hp scopes that have what appears to be a small TV like CRT?

[M0DSZ]

An analogue scope is best for radio although I had access to a Fluke/Philips 4-channel 200MHz digital/analogue scope for a long time, after about 10m years it failed. There was a lot of trouble because it contained AtoDtoA circuits making it very tricky to repair.

My employer purchased a number of Textronix digital scopes, made in China. They are not popular because, among other things, the triggering leaves much to be desired. This may noy be so important for RF work. The general construction isn't bad though.

Following this, another purchase was made of Instek scopes, similar in function to the Textronix and from the same source but not so well made and not popular.

Whatever you end up with, cursors to measure amplitude and frequency/timing are very useful, even essential.

[VK2TIL]

Sorry for delayed reply; I've been away.

"How do the TDS series compare with the 2430/2440 series stuff? Has anyone used any of the hp scopes that have what appears to be a small TV like CRT?".

My TDS-320 is the type with a "small TV-like CRT"; it's actually a small computer monitor.

Like this;

http://cgi.ebay.com/Tektronix-Dual-Trace-TDS320-Oscilloscope-FREE-SHIPPING_W0QQitemZ110281918747QQihZ001QQcategoryZ1 04247QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The instrument is in a "normal", ie fairly large, case; the standard Tek blue case used for the analog 'scopes.

It looks odd when you remove the case as it's less than half-full. Much of the interior is just air; I think Tek must have wanted to use-up their case stock and not re-tool for the much smaller case that could have been used.

It's different to the later "digital phosphor" models which I think have an LCD screen (I've never seen or used one).

It has cursors but I rarely use them; it reads frequency, amplitude etc in a digital readout on the screen.

I certainly like mine; I have a nice 465M but it's never used.

[AC0FP]

I was afraid of that. I have often found digital scopes less useful than analog scopes in how dirty signals are represented. I've used the newer compact TDS series scopes in the workplace and while I liked many of their features I also found the same irritation with noisy signals. I also did not find the user interface compelling although it's been long enough that I can't remember exactly what it was that I didn't like about them.

How do the TDS series compare with the 2430/2440 series stuff? Has anyone used any of the hp scopes that have what appears to be a small TV like CRT?

All of the Tek scopes here at work are TDS type. I'm sure I've used 2430's at one time but I can't remember for sure, however I do remember 15 years ago visiting a large equipment repair shop and saw a lot of Tek scopes in for repair. I asked and the technician told me the "new" Tektronix scopes fail a lot because of the new light weight switching power supply. I don't think these scopes were the TDS series.

HP makes lots of good stuff like spectrum analyzers and signal generators but not oscilloscopes. Everyplace I've been over the years employees have cussed HP scopes, including where I'm at now. In fact where I used to work the Director of Engineering, a PhD/EE type, was the biggest critic of HP digital scopes in the company.

For RF signals I use my Tek-465B at home to view waveforms! ;)

Usually the real digital type guys go for the Yokogawa digital scopes.

73,

Frank:)

[WA7KKP]

Do you want a digital sampling oscilliscope? Those are still big bucks, and I wouldn't have anything less than a 1 GHz sampling rate, which translates into a 500 MHz scope.

A 100 MHz scope is useable beyond 100 MHz, but the calibration becomes iffy. For most people, that's all you'd need.

Gary WA7KKP

[AB8RO]

Do you want a digital sampling oscilliscope? Those are still big bucks, and I wouldn't have anything less than a 1 GHz sampling rate, which translates into a 500 MHz scope.

A 100 MHz scope is useable beyond 100 MHz, but the calibration becomes iffy. For most people, that's all you'd need.

Gary WA7KKP

Hi Gary,

Yes, I find sampling very useful but not so much at high speeds. I use it more often for synth building than I do radio building so I don't want to give the feature up. Really, I like the style of scope that I have which essentially switches between being a sampling scope and being an analog scope.