Advice please about which frequency generator to buy

To All, Several years ago I was looking here for advice about buying an oscilloscope. The unit that got the most votes for my price range and experience was the Tek 465B. So I bought one and then later someone who used to post here sent me the meter kit that Tek used to sell and I installed it on the 'scope. The 'scope is way more than I need and so it has never let me down. Now I think I could use a frequency generator or a function generator. I'm not sure which or if I should have both. I don't have a lot of experience and the 465B has mostly been used by me for fun and self education. I have used it to diagnose problems on a couple CNC machines that I own as well as tuning some servo amps that I used on a home built machine. So the stuff I'm looking for now needs to be cheap but still of the quality level of the 465B. Something about the same age as the Tek 'scope probably. Thanks, Eric

Reply to
etpm
Loading thread data ...

WHat is your price range and your top end range of freq you wish to play with?

I have a function generator by rigol that will allow you to generate any patern you want up to 10Mhz I think? and the Sinewave output up to 20 or 25Mhz, I can't remember now.

As for a generator for RF use, you need to sepecify the range in mind 1 GHz?, 500 MHz ? etc.. Look around for a HP 8640B generator with the 1GHZ option in it. That gives you an audio generator as well with AM/FM modulation and freq counter that allows you to use it externally.. I have 2 of them :)

The Function Generator is a nice thing to have on the bench for creating periodic time signals in wave form shapes of your choice.

P.S. The RF generators normally do not come with a function generator that allows you to create special waveforms and very slow/long output signals.

You may want both! :)

Jamie

Reply to
M Philbrook

There seem to be some nice looking stuff comming out of China that is new. You can get them anywhere from circuit boards where you just add power and a case if you want them to some that are already in the case. I just looked and they are from about $ 15 for the ones without a cse, and nicer ones start around $ 75 and go to slightly over $ 100.

You did not state the frequency range, but as you said function generator, I would think that about 1 MHz would be the top of what you want. Some of them on ebay go to as much as 20 or 25 MHz and some to about 1 MHz.or less.

Just get on ebay and search for function generator.

Reply to
Ralph Mowery

In addition to a "real" hardware benchtop function generator, you might consider a PC-based unit that uses your sound card. It's only going to be good for the "audio" range, usually under 20 kHz (or 40 kHz with a card that samples at 96 kHz). And sound cards are AC-coupled so you won't get flat-topped square waves at low frequencies.

But what you do get is precision frequency accuracy, stability, and setability, and a mind-boggling range of modulation and waveform options. And up to 8 independent output signals (using a cheap USB sound card). all in perfect synchrony.

[PLUG] My Daqarta software includes such a signal generator that is absolutely FREE. (You don't need to buy Daqarta; while the 30-session/30-day trial expires for some features, like the signal *input* channels, the signal generator and most other features never expire.) See

Best regards,

Bob Masta DAQARTA v8.00 Data AcQuisition And Real-Time Analysis

formatting link
Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, Pitch Track, Pitch-to-MIDI FREE 8-channel Signal Generator, DaqMusiq generator Science with your sound card!

Reply to
Bob Masta

Hi Eric, Frequency range? Is 50 ohm output impedance OK? approximate price?

I like my Rigol sig. gen. ~$350 but it may be too much for you. maybe an old Wavetek (ebay prices start ~$50.)

Bob Masta's given you the PC sound card option.

You could also hack your own for low frequency stuff. a 555 timer.

Or I've got piles of ICL8038's kind of a function generator IC. I could send you some to play with. (used in a discontinued instrument)

formatting link

George H.

Reply to
George Herold

Thanks for all the great replies guys. I think Jamie is correct, I probably should have both a frequency and function generator. I'll get the function generator first. After reading your post Ralph I looked at ebay and there is now WAY more of this type of equipment coming out of China than when I bought my 465B. It might be a good idea to buy something cheap and then I can learn enough to make a more eductaed decision about buying something better. You have mentioned Daqarta in past several times Bob and I am going to try it now. I'll give it a shot before I buy something from ebay.Thanks for your shameless plug. That ICL8038 looks great George. Easy to make a circuit on a solderless breadboard. I would really appreciate it if you sent me some. That was a nice offer. Once again, thanks for the replies, it is this kind of thing that helps amateurs like me. Eric

Reply to
etpm

Eric, drop me an email (gherold at sign teachspin.com) with a shipping address and I'll stick some in the mail. (We've got >200 of these, the previous person doing purchasing was a bit out of control at times.)

George H.

Reply to
George Herold

I have a B&K 4003A and it's very useful. It's about $375 new, but you can probably find something similar for less somewhere, with the same basic features: sine/square/triangle/pulse, DC offset, attenuator, sync output, 50 ohms.

I used mine recently to measure the inductance of some flat parallel-copper-strip cables, in the 10s of nH, something few LC meters can measure.

The old Waveteks were good, but most have probably failed by now.

Reply to
John Larkin

1980s-era Waveteks sometimes blow up if you hang a 50-ohm load on them.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
 Click to see the full signature
Reply to
Phil Hobbs

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.