Help me set my gains with my o-scope

[ShockTherapy]

Hi everyone. I have my Genesis DMX in my truck and would like to set the gains properly. I have a handheld o-scope that I would like to use to set things legit. Here is a picture of the unit I'll be using.

I understand about starting at the headunit. does this mean that I unplug the rcas from my amp then hook up the leads to them and raise my volume until the deck itself clips then turn back a little? then do the same to the amp? This unit is foreign to me, I've never used it. Cansomeone help me out on this? I'd like to dial this in the right way. For the life of me I can't find a manual for this thing.

[12voltjunky]

[ttocs]

I am not familiar with that model to give a step by step on it, but forgive me if I make sure that you understand what the divisions are for, and what adjusting them means? You said you have used a scope a couple of times I just want to make sure that it is enough that you know how it works or if you need to know how that specific scope works?

do you have a disk with a couple of different test freqs? If not I will need to look and see where I got mine from. You know what the clipped wave looks like right?

Please understand I am just trying to find out how much you already understand so I/we do not go over your head. I know you are an electrition but we can all agree this is a different animal. Just the opposite is true that I have years of experience in the bay but you would not want me wiring your house even though I took a class in high school about it....

You did this already with a meter right? If so please take note of where all the gaines are set at now before we start as I would love to see what the difference is between the two. Might have me eatin crow ya know.....

[ShockTherapy]

I have a 60hz test tone disc as well as a 1000hz test tone disc. Setting gains with the dmm is easy but I have been told that the o-scapeis better and more accurate. I have no friggin clue how to use it. I'm a Commercial/Industrial Wireman... We don't even tinker with these things. I dinked around with a scope in electrical class but most of us weren't paying attention since we figured we'd never use it. as for me knowing what a clipped wave looks like, nope. and as for divisions on it, nope. using a dmm is second nature but this thing is a lot more complicated.

[ttocs]

ok cool, so now we know where you are with it. I went to electronics tech-school so we spent alot of time on them. There will be a bit to cover so let me know when we get over your head, chances are that we skipped something but this could be a good learning experience for you as well as a good post for others.

take a look at the older scope on the right of this page.:
http://en.wikipedia.org/wiki/File:WTPC_ ... cope-1.jpg
there are two dials on it, one listed volts/div and the other secs/div. This tells what each one of those squares on the screen is equal to with time going from left to right and voltage going top to bottom.

Get a picture of yr scope when it is on, the function keys will be how this thing operates I think. When you do turn it on it will make a grid on it of horozontal and verticle divisions. The horozontal(top to bottom) divisions are voltage, the verticle divisions(left to right) are time divisions. Somewhere on the screen there will be a V=XXXVolts and T=XXX(milli/micro seconds), that is what each on of those squares is is equal to. (from the page listed above)So if your V=.1v per division, and the wave that we end up measuring goes up 2.8 squares before it starts to go back down then it is .1V/div x 2.8divisions=.28V on the top peak before it turns around and goes back down.

am I speaking chinees yet?

[ShockTherapy]

Not chinese yet but getting there. I understand the math and see where you're going so far.

[ttocs]

now the next question is do you understand the sine wave and what happens when it makes one cycle, and how that would move the speaker? Do you understand how the time it takes to make one cycle is how we figure out what frequency the sound is? I think it will be easier to do this in sections to make sure I don't skip anything.

Is anyone else gonna say somethin? I know I am not the only one that has worked a scope before so please chime in if you have something to add or if I messed something up.

[gbody805]

Subscribed!

Please don't mind me, I'm only here too learn something.

[ShockTherapy]

Just got off work sorry... worked a 13 hour day. I'm friggin spent. Ok back to the topic. I remember that an AC electric charge periodocally reverses direction to create a waveform. and DC only goes in one direction if I remember correctly. This is very vague to me since I haven't touched on this since my second year in the beginning of my Electrical Apprenticeship. And of course I know that the US is 60hz.

[ShockTherapy]

Did you decide to stop helpin me? I'm still pretty lost. i will get my power cable and new rcas today so im going to finish things up. is there more to this? because I'm still kinda lost.

I still don't know what a clipped waveform looks like. and do i start at the deck's rcas? im guessing I turn up the volume on the deck while metering the rcas til something happens? umm

[Eric D]

http://www.bcae1.com/settinggainswithscope.htm

That is pretty technical, but if you read it over it should help you understand a lot of what you need.

[ttocs]

ah shit man sorry, I have not seen this for a while.

yes you are right just clip the test lead on the center pin of the rca outputof the deck. hell that thing probably has autoraning and will set the x and y to where you need it.

Do the deck first, then do the same thing but now on the other side of you amp on the speaker wire. The voltage will go up alot, but the shape should not change unless you clip it.