Function generator and oscilloscope

Thread Starter

BC547

Joined May 22, 2018
38
Hi,

I am starting out to learn electronics myself with parts and accessories. In order to perform experiments from standard books I would need to see the waveform and generate signals to test the circuits. However i am not sure what equipment to buy. I dont fancy hitech stuff yet not very cheap either. Is it worth buying such equipment ? What would you suggest i buy ?

Thanks
 

DickCappels

Joined Aug 21, 2008
6,776
...and then when you get a scope you will know to throw out the solderless breadboard :) (maybe- I'm just showing my prejudice)

What kinds of circuits interest you? Audio amps, RF, digital logic, microcontrollers, instrumentation...?

You can go for a long time without an oscilloscope but even cheap ones can give you insight into how things work that you might not fully understand from books. If you get a scope I suggest two vertical channels plus a trigger input.
 

Thread Starter

BC547

Joined May 22, 2018
38
...and then when you get a scope you will know to throw out the solderless breadboard :) (maybe- I'm just showing my prejudice)

What kinds of circuits interest you? Audio amps, RF, digital logic, microcontrollers, instrumentation...?

You can go for a long time without an oscilloscope but even cheap ones can give you insight into how things work that you might not fully understand from books. If you get a scope I suggest two vertical channels plus a trigger input.
For a start i am going to build digital logic and some other with microcontrollers.
Thanks for the reply.
 

hexreader

Joined Apr 16, 2011
470
I play around with microcontrollers all the time. Solderless breadboard is fine for simple circuits up to 100kHz or so, as long as you realise that any unexpected (small) distortions may be a feature of breadboard and not necessarily real.

I would consider an oscilloscope almost essential. If you can afford Rigol DS1054Z then that is the best bang-for-buck that I know of, and is very popular with hobby users. A cheaper scope might be good enough, but less of a pleasure to use. Any scope is better than no scope.

A signal generator is far less essential in my experience, but nice to have. A cheap one might be all you need.

A $10 to $20 8 channel logic analyser is great for microcontroller experimenting too.

Just my thoughts and opinions - feel free to ignore
 

DickCappels

Joined Aug 21, 2008
6,776
I lived for nearly two years without an oscilloscope when in S.E. Asia, but when I visited the United States every few months I had plenty of things to test using my scope and function generator. In a little corner of S.E. Asia far from the nearest place to buy any test equipment I did most of my troubleshooting of RF and microcontroller circuits using a $10 digital voltmeter and a "crystal" earphone. It is amazing what you can figure out by listening to some signals.
 

BobTPH

Joined Jun 5, 2013
2,721
I almost never use my scope or signal generator on my microcontroller projects. They are much more suited for analog circuits. A multimeter with frequency and duty cycles ranges is good to have though.

Bob
 

MrChips

Joined Oct 2, 2009
22,468
Start with a DMM. That is a must have.
You can do a lot of microcontroller diagnostics with one or more LEDs.
Next would be a DSO138 digital oscilloscope. Play with this until you gain enough experience and you outgrow it.
If you want to skip over the DSO138 then look at the Hantek handheld digital scopes. Model 2D73 has DMM and signal generator included.
 

KeithWalker

Joined Jul 10, 2017
1,386
I design and build analog, digital and microcontroller circuits. The digital voltmeter is the most important tool. Make sure it has DC current ranges on it. My second most important tool is my oscilloscope. I am retired and on a very limited budget. When my 40 year old HP scope CRT finally died on me, I bought a second hand 60 MhHz dual channel analog scope for $40.00. It does everything I need. I made my own audio oscillator, function generator and frequency counter. It's very easy to do with the abundance of inexpensive components available on AliExpress. You just need a bit of patience for the long delivery times. Some people bad mouth the quality of Chinese components but I have never had a problem with them for hobby applications.
Regards,
Keith
 

BobTPH

Joined Jun 5, 2013
2,721
Start with a DMM. That is a must have.
I would definitely recommend one with frequency measurement ability though. With microcontrollers you are often setting things up to run at a specific frequency and it does not always often come out right the first time.

Bob
 

Ian0

Joined Aug 7, 2020
1,097
I bought the bottom-of-the-range Tektronix digital scope. At work I have a much higher spec, higher frequency Isotech scope - but I much prefer the Tek. I paid £400 for it, and as soon as I got it the supplier put it on special offer £100 cheaper. (Annoying)
It gets a lot of use with microcontrollers. Did it send the CAN message? Does the baud rate look correct? Is the PWM the right frequency?
My multimeter can measure frequency up to 50kHz, but that doesn't tell me if data is being sent correctly.
I used to buy cheap multimeters, as a student and they would last a couple of years. I bought a Fluke with my first real pay-cheque. It was still accurate even when it was 20 years past it recalibration date!
Most digital scopes have a "measure" function, so you can use them instead of a multimeter (the scope stays on the bench, I could have left the multimeter anywhere) but they don't measure current.
My (home made) signal generator gets used on audio projects but rarely anywhere else.
 

dl324

Joined Mar 30, 2015
12,210
I dont fancy hitech stuff yet not very cheap either.
Since you don't know enough to know what you need, buy cheap and get something better when you know you need something better.
Is it worth buying such equipment ?
It absolutely depends...

I bought a bunch of used equipment (analog scopes, digital scopes, logic analyzers, bench multimeters, frequency counters, signal generators, curve tracer) around 15 years ago. Most of it is going for 5-10 times what I paid back then. It was definitely worth it to me.
What would you suggest i buy ?
I bought a DSO-138 assembled for $20 and it's a handy tool. Not great, but not horrible either. It's definitely better than nothing and who can't afford $20? One limitation of that scope (aside from it's low 200kHz bandwidth) is that it needs a power supply. So, for about twice the price, I bought a FNIRSI Pro that's battery operated and 5MHz bandwidth. For quick measurements, I use the cheap scopes because I've usually finished measuring what I needed even before the analog scope would be warmed up.

If I need/want more channels, I'll use one of my Tek mainframes.

It's okay to buy more than you need, but what if you decide learning electronics isn't something you enjoy?
 

dl324

Joined Mar 30, 2015
12,210
Does buying a handy device like the DSO-138 motivate beginners?
It depends on the individual. Some might understand more by using it. Others might not be able to figure out how to use it, get frustrated, and give up on electronics.

Not everyone is cut out to self teach electronics. I'd say most aren't going to be very successful.
 

BobTPH

Joined Jun 5, 2013
2,721
DSOs are not easy to use. I would not recommend them as a first scope, especially for someone trying to learn on their own.

Bob
 

DickCappels

Joined Aug 21, 2008
6,776
On the other hand I ran through a bunch of CRT based scopes, replacing one every 5 years on average. I've been using the same Tektronix low-end digital scope for 18 years without a complaint.
 

Ian0

Joined Aug 7, 2020
1,097
My Tek 20MHz scope is great. But having spent all that money on a fancy injection mould tool for the case, why didn't they mould in a place to keep your hook-probes?
 

dl324

Joined Mar 30, 2015
12,210
I've been using the same Tektronix low-end digital scope for 18 years without a complaint.
My favorite scopes are all Tektronix from the 70s-90s. After around 15 years, I have a 15MHz SC502 and 100MHz 466 that need to be repaired, but my Tek 7xxx mainframes (100-250MHz) and plug-ins have held up well.
 

MrChips

Joined Oct 2, 2009
22,468
When you need to see a low repetition signal or a one-time event such as a single byte transmitted by a UART you will get to appreciate a digital oscilloscope.

My workhorse is a Tektronix TDS220.
 

Thread Starter

BC547

Joined May 22, 2018
38
When you need to see a low repetition signal or a one-time event such as a single byte transmitted by a UART you will get to appreciate a digital oscilloscope.

My workhorse is a Tektronix TDS220.
Why do standard oscilloscopes cost a fortune? Plus it's a huge investment. Why aren't student friendly, amateur-type oscilloscopes never designed by corporations? The basic models are still bought by colleges, research engineers or experienced professionals. I bought a fluke multimeter but can't set my eyes on a similar value OSC.
 
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