EEVblog Electronics Community Forum

Products => Test Equipment => Topic started by: freebil on May 17, 2016, 03:55:13 pm

Title: Analog Oscilloscope h1740a used
Post by: freebil on May 17, 2016, 03:55:13 pm
Hello. I would like to buy my first oscilloscope. Is the hp1740a ok for electronics hobbyist? How much money I have to offer to a friend that sells it? Thanks!
Title: Re: Analog Oscilloscope h1740a used
Post by: tggzzz on May 17, 2016, 04:22:04 pm
I have an hp1740a, and like it. It is equivalent to a Tektronix 465, which you will find is highly regarded.

Such scope will be useful for many hobby activities, but not all. The main limitation is that such scopes require a repetitive waveform; there is no storage.

But you should regard that as a challenge, not a problem. Why? Because with understanding, thought, and imagination and other tools in your toolbox, you will usually find it possible to get many things working. That looks good on a CV, and when you find you absolutely cannot debug a circuit because of X, then you will know exactly why you need something else.
Title: Re: Analog Oscilloscope h1740a used
Post by: oldway on May 17, 2016, 04:32:35 pm
The analog oscilloscope HP1740A is a great instrument with a bandwidth of 100Mhz, which is more than enough for a beginner.

This oscilloscope is the competitor of the Tektronix 465.
It has the advantage of not having fan.

His only major flaw is its size: it uses a large space on the bench.
It is quite robust and reliable but spare parts are very rare.

Like any old device, it's a lottery: you must be sure it is in perfect working order before concluding the purchase.

Its value is less than that of the Tektronix 465 or 465B that is more often sought.

In good condition, I believe its value is within an hundred US $.

After purchase, check his bandwidth as some HP1740A have an oxidation problem of the delay line.
It's not serious, just disassemble and move the delay line in all directions and the fault disappears.
Title: Re: Analog Oscilloscope h1740a used
Post by: nctnico on May 17, 2016, 04:37:37 pm
Firstly: I wouldn't spend a couple of hundred US dollars on an analog scope while you can buy excellent digital scopes starting at less then $400.
Secondly: getting old equipment is always a gamble. It might work today but how about tomorrow? My rule of thumb is to stay away from anything more than 20 years old.
Title: Re: Analog Oscilloscope h1740a used
Post by: oldway on May 17, 2016, 04:54:48 pm
On older equipment as HP1740A, failures are occuring in parts that can still be found on the internet as electrolytic capacitors, semiconductors, operational amplifiers, CMOS logic 4000, ...

The unit remains serviceable.

A beginner does not need a storage scope, I really do not understand what a digital scope can bring as advantage.

An analog scope is easier to use.
Title: Re: Analog Oscilloscope h1740a used
Post by: freebil on May 17, 2016, 04:56:15 pm
Thanks for the answers! I would like to buy a rigol 1054, but I have not the money now.. I have an electronics and computer engineer diploma and I would like to try electronics as a hobby now and maybe learn about how to repair electronic boards. I have 70-80 euro. I found a gw gos653 too. How it is compared to hp1740a? I live in Greece, so I search on ebay in Europe and auction sites in Greece. So, for analog scope do you suggest me to go for a digital storage analog?

PS. I attach the gw gos653.
Title: Re: Analog Oscilloscope h1740a used
Post by: oldway on May 17, 2016, 05:04:20 pm
Nothing to do with technology and quality of a HP product  :--
This scope on the picture seems to have a failure of horizontal amplifier.
Title: Re: Analog Oscilloscope h1740a used
Post by: tggzzz on May 17, 2016, 05:05:10 pm
Like any old device, it's a lottery: you must be sure it is in perfect working order before concluding the purchase.

That would be wise for a beginner.  A beginner doesn't have the experience to debug inside a scope, where +17kV -2kV can be found.

If repair is necessary, full service manuals are available and many people will offer remote help.

Quote
Its value is less than that of the Tektronix 465 or 465B that is more often sought.

Yes, but I've never understood that. I suspect it is that more people used a 465.

Having repaired both a 465 and a 1740, IMNSHO the build quality of the HP is better.

In terms of use, neither is better than the other; they are both good.

Quote
After purchase, check his bandwidth as some HP1740A have an oxidation problem of the delay line.
It's not serious, just disassemble and move the delay line in all directions and the fault disappears.

Do a thorough check before buying. Make sure all controls work and that they aren't noisy.

If the risetime increases from 3.5ns to 7ns (as mine did), then just remove the cover, and squeeze/fondle/molest the delay line without removing it.
Title: Re: Analog Oscilloscope h1740a used
Post by: tggzzz on May 17, 2016, 05:16:44 pm
Thanks for the answers! I would like to buy a rigol 1054, but I have not the money now.. I have an electronics and computer engineer diploma and I would like to try electronics as a hobby now and maybe learn about how to repair electronic boards. I have 70-80 euro. I found a gw gos653 too. How it is compared to hp1740a? I live in Greece, so I search on ebay in Europe and auction sites in Greece.

I don't know the gos653, but if the price is the same and they both work, get the HP.

OTOH, if the GOS is much cheaper and you could use the money to get other necessary equipment, that would be worth considering.

Be very aware that packing scopes for transport isn't easy. They often arrive with broken knobs, shattered tubes, or tubes with subtle internal damage. (See a 465's damaged tube in my .signature.) Inspecting a scope before purchase and avoiding transportation damage is strongly in favour of the HP1740.

Quote
So, for analog scope do you suggest me to go for a digital storage analog?

It is better to get a good analogue scope (HP1740/Tek465) than not have a scope.

The one time I needed a storage scope in the past 25 years was when debugging the switchmode power supply of my 485. I had to observe the startup sequence, and I could only do that once every 6 hours! I used a 10MHz Analog Discovery - which I bought for its AWG, pattern generator and LA.
Title: Re: Analog Oscilloscope h1740a used
Post by: daqq on May 17, 2016, 05:25:06 pm
Quote
A beginner does not need a storage scope, I really do not understand what a digital scope can bring as advantage.
Have fun debugging SPI/I2C/digital system of your choice or viewing nonrepeating signals without storage. While it is true that it CAN be done, it can be done very slowly and painfully. Basically, there's no reason NOT to have a digital storage oscilloscope these days.
Quote
An analog scope is easier to use.
No.
Title: Re: Analog Oscilloscope h1740a used
Post by: tggzzz on May 17, 2016, 05:37:34 pm
Quote
A beginner does not need a storage scope, I really do not understand what a digital scope can bring as advantage.
Have fun debugging SPI/I2C/digital system of your choice or viewing nonrepeating signals without storage. While it is true that it CAN be done, it can be done very slowly and painfully.

With imagination, it is usually possible, e.g.:
In other words, structure your design and its implementation so that you gradually expand the functionality, bit by bit. That's much better engineering than throwing something together and seeing what does/doesn't work this time.

Quote
Basically, there's no reason NOT to have a digital storage oscilloscope these days.
Quote
An analog scope is easier to use.
No.

It is easier for a beginner to understand an analogue scope because all the controls are visible and not hidden as options in sub-sub-sub menus.

There is an excellent reason to not have a DSO: the money could better be spent in other ways.

"A bad workman always blames his tools"
Title: Re: Analog Oscilloscope h1740a used
Post by: nctnico on May 17, 2016, 05:42:32 pm
My first DSO was a Tektronix 2230 which basically was a hybrid between an analog scope and a DSO because you could use it in both modes. Not exactly on par with today's DSOs by a long shot but still I ended up using the DSO mode all the time and the analog mode just became cumbersome to use. Cursors to do measurements of amplitude and time are easy to get used to. Add the ability to do automated measurements, store data, make screendumps, etc found on today's DSOs makes the choice a no brainer if you have the money to spend on a DSO. Heck I'd even choose a crappy Tektronix TDS210/TDS220 DSO over any analog scope.

edit: typo
Title: Re: Analog Oscilloscope h1740a used
Post by: freebil on May 17, 2016, 06:41:57 pm
Thank all of you for the answers. I have to say that I have a logic analyzer clone for ebay and I ordered a multimeter ut-139c..
Title: Re: Analog Oscilloscope h1740a used
Post by: oldway on May 17, 2016, 07:38:29 pm
Quote
After purchase, check his bandwidth as some HP1740A have an oxidation problem of the delay line.
It's not serious, just disassemble and move the delay line in all directions and the fault disappears.

http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1983-01-02.pdf (http://www.hparchive.com/Bench_Briefs/HP-Bench-Briefs-1983-01-02.pdf)