Analog Oscilloscope bandwidth considerations

I'm often asked by hams and hobbiests - I want to buy an oscilloscope, what bandwidth scope do I need? I usually answer - buy as much as you can afford, even if you are working on low frequency circuits. This video shows an example of why. Even simple audio circuits might have some hidden evils!

Category:

Science & Technology

Tags:

• W2AEW
• oscilloscope
• scope
• bandwidth
• BW
• band
• width
• tektronix
• phase
• shift
• oscillator
• audio
• oscillation
• spurious
• emissions
• parasitic
• parasitics
• capacitance
• loss
• transistor
• probe
• output
• 20MHz
• 350MHz
• 2467
• tek
• breadboard
• circuit

[supertruckertom]

Would a 2230 have been able to spot that oscillation? It might not have been able to fully resolve it due to the 100 mhz bandwidth but would the blurred trace be evident? I guess I need to build something similar and find out. Is that something that the choice of test leads could affect as well?

[w2aew]

@supertruckertom The 2230 would show you the bursts of oscillation. However, since the 2230 is a 100MHz scope, the amplitude of the 200MHz bursts would be somewhat reduced in amplitude. The delayed timebase on that scope would probably not show you a clear view of the sinusoidal oscillation because a) the CRT in that scope doesn't have the writing rate of the 2467 that I used, and b) the trigger circuit in the 2230 might not be able to trigger on a 200MHz signal.

[321reh]

@w2aew My Dream scope would be the Tek 2465...300Mhz B.W. ....More Than Enough!!!

[w2aew]

@321reh Yes, the 2465 (and 2467) were probably the best 4-channel portable analog scopes ever made - IMHO.

[jaak68]

It's always handy to have a Tektronix Application Engineer posting videos! Thanks!!!

[w2aew]

@jaak68 Thank you! Of course, I learned to drive a scope long before I came to work for Tek. Thanks for watching.

[nlimchua]

Could you do a video of checking capacitors in-circuit using a scope and function gen? This would be very helpful for a lot of viewers and I don't see good video postings anywhere of this topic. thx!

[aortiz557]

what an informative video, thank you very much for posting this, gives me more reason to replace my aging 20mhz o-scope.

[321reh]

Another Interesting Video that you actually LEARN something from, And it Doesn't hurt that You're a Tektronix Application Engineer!!! Tek Scopes are my Favorite( I own a 2225) Thanks!!!

[Radiowild]

Great presentation! You brought up a good point which most of of us would never consider when looking for a scope/upgrade. Got any for sale? Remember I'm a cheap ham! Hi! KC2RDU/ RW