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Oscilloscope question
https://forum.lddb.com/viewtopic.php?f=30&t=8057		 Page 1 of 1
Author:  audioboyz1973 [ 14 Oct 2018, 06:08 ]
Post subject:  Oscilloscope question
I've wanted to try to teach myself some LD alignment/repair basics beyond the simple mechanical stuff for a while now.

Already have a copy of the Pioneer test disc (GGV 1069) and a generic service remote from ebay, now need an oscilloscope.

Just starting out I'm not looking to spend a lot of money; and the main options at lower price points that I've been looking at are analogue 20MHz scopes.

As I understand it the highest RF frequency coming off an NTSC disc is a bit over 9MHz and for Muse that's a bit over 14MHz; but are there higher frequencies elsewhere in the circuitry I might need to measure? I've seen suggestions that your scope should be capable of five times the signal you're measuring? Is a 20MHz going to be sufficient or should I be looking for something higher?

Thanks for any advice you can give.
Author:  krbahr [ 15 Oct 2018, 02:18 ]
Post subject:  Re: Oscilloscope question
To go to a compact size as I bought a Tektronix TDS210 digital scope and it works fine. Just takes less space than my analog ones. It was around $100 used on eBay.

You need to make sure it has a X/Y function as not all oscilloscopes have that.
Author:  audioboyz1973 [ 15 Oct 2018, 11:06 ]
Post subject:  Re: Oscilloscope question
Thanks Kurtis,

Sometimes I envy you guys in the states where there seems to be a much bigger second-hand market. There's not so much here especially locally. From a quick check of that model on ebay the cheapest one there at the moment (not listed "for parts") that ships internationally would be about $300US including shipping and import duties (which are about as much as the scope itself). or over $400AUD on current crappy exchange rates.

I did get ahead of myself on this a little bit and had put in a low bid on one of these: http://speech.di.uoa.gr/dsp/program/TOOLS/lgosctechnicalsheet.pdf. Didn't really expect to win at the time, but ended up owning it earlier today. It's here in Perth too - no shipping and no duties! Has X/Y so hoping it will do the job.

If it turns out to be not up to the task I'll just wait out a more local / better deal on the tektronix. Can definitely see the benefit of something more compact like that.
Author:  jefflang [ 19 Feb 2022, 14:57 ]
Post subject:  Re: Oscilloscope question
krbahr wrote:
To go to a compact size as I bought a Tektronix TDS210 digital scope and it works fine. Just takes less space than my analog ones. It was around $100 used on eBay.

You need to make sure it has a X/Y function as not all oscilloscopes have that.


Question: I read that an analog scope is better than a digital one for audio/video work.
But it sounds like you are saying for what we would use it for, (calibrating laserdisc players), a digital one like you mentioned would be sufficient.

Jeff
Author:  krbahr [ 20 Feb 2022, 01:51 ]
Post subject:  Re: Oscilloscope question
Digital works as long as you don't sync on harmonics. You just need to know how to use a digital scope and they work fine. I prefer analog but digital is much more compact and cheaper.
Author:  cplusplus [ 20 Feb 2022, 20:11 ]
Post subject:  Re: Oscilloscope question
I have a digital and analog, both Tektronix. I can't get a clear eye pattern with the digital scope, but other than it is fine.

With analog scopes you need to make sure everything is still functioning correctly, and that all the knob and switches are clean so it doesn't muck up the signal. That being said, my analog 2246A is my main scope.
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