BK 4017A Sweep Function Gen. Uses for beginner? - Page 1
Forum section: electronics / beginners

author: opensourcefan
author_rank: Contributor
timestamp: February 06, 2016, 09:38:00 pm
content: Hello all, I recently got started playing with my scope (V-222) and I wanted to see and play with some wave forms. I tried a simple circuit but it was too slow to show much so I went out and picked up a XR2206. Built up a circuit and played with that for a bit and it was fun so I decided to search around for maybe a "real" or better function gen.I managed to find a BK 4017A 10MHz for $45 on ebay. It had a bit of superficial damage so it was a gamble but it works nicely so I got lucky. I think that's a decent price for a newish entry level F-Gen right?Anyways now that you know what would posses this beginner to get a F-Gen does anyone have any idea on simple fun things I can with it? Maybe I use the wave forms in a circuit or something. I haven;t graduated to building circuits with clocks yet but am willing to learn. After all my reading and watching videos it seems like it's not quite a beginners piece of equipment and maybe a more specialized device all together. I did go pick up a 50 ohm terminator and BNC stuff so I can measure correctly on my older scope.Sorry for all the preamble, that was to let you all know where my mind is at.

author: uncle_bob
author_rank: Unknown
timestamp: February 06, 2016, 10:00:29 pm
content: HiOk so intro to circuits and signals with a function generator:Grab an R and a C. Let's say it's a 1K and a 1 uf. It could be anything. There are a couple ways to hook them up and a number of signals you can feed them.The traditional starting point is a sine wave and a search for the maximum output voltage (with a fixed input voltage). Next search is for the 3 db ( times 0.707 V) and 6 db (half voltage) points. Step two is to look at the input and output on the two scope traces. Watch the phase shift between the two traces as you vary the frequency.Next up is a square wave and you sort of try to do the same thing .... hmmm ... odd results.Try a triangle wave ... again odd results.Off to a study of the Fourier transform and a bit of learning on why it looks odd. Back to the scope and a verification that he got it right.Bob

author: opensourcefan
author_rank: Contributor
timestamp: February 07, 2016, 12:08:26 am
content: Thank you Bob, I'll give that a go and see some oddness for myself, should be fun.I also found this amp circuit, looks interesting as well.http://www.instructables.com/id/Voltage-Amplifier/?ALLSTEPS

author: opensourcefan
author_rank: Contributor
timestamp: February 14, 2016, 09:17:24 pm
content: Well that was interesting Bob. I did what you said and it produced some interesting results. I'm seeing filtering some phase shifting. I understand why I'm seeing the filtering but don't understand why the phase shift, time to go study. The higher the frequency the smoother the filtering turned out to be, understandably so. It's so cool to see this in action.

author: uncle_bob
author_rank: Unknown
timestamp: February 14, 2016, 09:41:20 pm
content: Quote from: opensourcefan on February 14, 2016, 09:17:24 pmHiThere is a very good reason for the phase shift. It's central to a bunch of AC circuit theory. It is well worth digging in to for that very reason. If this locks you up for more than a day or two, come back here and I'll at least give you some help understanding what is going on. Each time I say anything remotely related to "teach" the professional educator on the other side of the dinner table lets me know just how little I know about that fieldBob