Function generator - which one would you recommend?

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#1
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Hi

I need your advice concerning signal generator.
I decided to buy oscilloscope Tektronix TDS2024B and I also want to buy signal generator and questions start to arise.

What brands are good?
Which one would you recommend?

I think price should not exceed 500 Euros

I am waiting for your opinions.

Adam

Last Edited: Fri. Jun 19, 2009 - 06:09 PM
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I've got two Marconi 2019A signal generators (80 kHz to 1024 MHz). They are a bit bulky and heavy, but work very well, and can be picked up fairly cheaply. They are very reliable, and quite easy to repair if they do go wrong. They actually go down to 10 kHz but the spec. isn't guaranteed. We had lots of them in our lab when I worked at Racal a few years ago.

Leon

Leon Heller G1HSM

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This is one of those questions where in the end everyone will have listed the generators they own or once have worked with :-) So I'll do something different.

Start with some basics, answer the following questions for yourself:

What frequency range?
What waveforms?
Desired frequency resolution, accuracy, precision?
Acceptable temperature drift? Long-term, short-term?
Required amplitude range? DC offset range?
Amplitude accuracy?
Waveform specific parameters like rise and fall time, duty cycle, symmetry, harmonic and spurious distortion or amplitude flatness?
Technology (analog, DDS)?
New or used?
Features?
. Number of channels?
. PC interface?
. External clock input?
. Trigger input and output?
. Additional frequency counter?
Modulation types?
Available in your local market?
Service locally available?
Calibration service locally available?

You don't have to have answers to all these. But when you start to find some answers and make up your mind you get a better feeling what is a suitable generator for you.

Because what is good for others might not be what you want or need. And in the end you have to make the decision, not we.

Stealing Proteus doesn't make you an engineer.

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Wow Arnold I am impressed with your answer! Thank you :) It is hard to say precisely what I need. For now I am not working with high frequencies and I don`t need high precision. But I believe later when I start new research I will need high frequencies and accuracy

Anyway what I expect:

frequency range: should start from 0 to 10 Mhz(or more)
waveforms: basic one like sine,square,triangle

frequency resolution: maybe 0.1 Hz or higher

Required amplitude range: now I work with an old one whose range is -15V to 15V and this is fairly enough for me.

DC offset range: definitely should have!

Its precision should be high enough but it is obvious it costs. As I said before 500Euro or less would be ok for me.

Quote:
Features?
. Number of channels?
. PC interface?
. External clock input?
. Trigger input and output?

It would be nice to have above features and maybe 2 or 4 channels.

I live in Poland so I would like to find representative from here. Service is also important.

Marconi signal generators` range is not from 0 so they don`t meet my requirements.

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I don't use "signal generators" as such much, but I would love to have an arbitrary waveform generator.

I agree with ArnoldB though, you need to judge it based on what you can reasonably expect to need, and what you can afford. Older gear, if it meets your needs, can give you a lot of bang for the buck.

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What you have described is a function generator, not a signal generator. Thandar makes some nice ones:

http://www.tti.co.uk/products-tti/gens-main.htm

They aren't expensive.

Leon

Leon Heller G1HSM

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Thanks Leon I used wrong word. Yes I need general purpouse function generator. Thanks for the link.

Adam

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If you just need sine, square and triangle waveforms ADI makes a DDS chip that should do what you want. They are quite easy to use. Here is a design of mine (it only generates sine output):

http://www.geocities.com/leon_he...

It won't be as good as the Thandar DDS instruments (they use an FPGA) but it's a lot cheaper.

Leon

Leon Heller G1HSM

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I have some funds from my University so I would prefer to buy a "ready to use" one ;)

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Of course, Agilent and Tek make them as well, but you will pay a lot more.

Leon

Leon Heller G1HSM

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I like Arnold's list.

Look for Sweep spec's as well. Slightly different than modulation capabilities.

JC

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Here is the little unit I bought for home use. It has an arbitrary waveform generator, 8 channel IO, and is a 20MS/sec dual channel oscilloscope.

http://www.syscompdesign.com/cir...

The main advantage is the software for it is open-source and runs on Linux, Mac, and windows. I have already customized the heck out of my software. Still, the standard software is pretty decent considering the price range.

Hope this helps.

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I have a TDS2024 o'scope and it is quite a nice little tool - I think that you will like it.

Based on some of your responses, I think that an arbitrary waveform generator - sort of an advanced function generator - would suit your needs.
IF your limit really is 500 Euro, it will not be so easy to find a brand new commercial with warranty&calibration at that price range, but if you shop carefully for used ones from rental companies or the like - or if this is for university work many will provide educational institution discounts to you.

If you don't already know - if you want the Tek arbitrary waveform generator you can shop on the Tektronix (tekDirect) online store in their "reconditioned" equipment section - though lightly used, they come fully tested &calibrated and with full mfg warranty and you might save as much as 25% depending on model, etc.

Also, look into BK Precision Model 4075 arbitrary waveform generator (0-25MHz). I have the predecessor to this model (4070A) and it has been pretty good over the years.