looking for a Oscilloscope

[Captain Kilowatt]

543 I agree with you on everything you said 100%, minus the bold part; I would recommend a 50 MHz minimum bandwidth scope for sampling a 27 MHz signal (based on what I've read and seen on the net).
I never tried with a scope less than 75 MHz so I can't say from experience what would happen but I vaguely remember something about a sample rate (I forget exactly what) being said on a "Ham Nation" episode.

The closer you get to the frequency limits/bandwidth of the device your sample will not be as accurate, if I remembered what they were talking about. Apparently not lol, because my memory is shot.

Once you start looking at a signal above the frequency limit of your scope the vertical accuracy starts to decline however most scopes are usable beyond the design limits somewhat without a serious decline in accuracy as long as it is not far beyond the limit. This only becomes an issue if you are looking for actual levels. If you simply want a station modulation monitor a 20 MHz scope is plenty accurate for that as you are only looking at audio rates and not 27 MHz or more. I have used a 20 MHz scope to look at 29 MHz modulation and 50 MHz was possible but the vertical accuracy for measurements was way off however modulating waveforms were fine.

 

[LeapFrog]

Once you start looking at a signal above the frequency limit of your scope the vertical accuracy starts to decline however most scopes are usable beyond the design limits somewhat without a serious decline in accuracy as long as it is not far beyond the limit. This only becomes an issue if you are looking for actual levels. If you simply want a station modulation monitor a 20 MHz scope is plenty accurate for that as you are only looking at audio rates and not 27 MHz or more. I have used a 20 MHz scope to look at 29 MHz modulation and 50 MHz was possible but the vertical accuracy for measurements was way off however modulating waveforms were fine.

Thank You Captain Kilowatt, I appreciate the clarification.

 

[Robb]

Since digital scopes have been introduced, companies have abandon the analog units and have sold them for chump change. There are a flood of analog scopes out there just waiting to get scooped up and find the right home for pennies on the dollar of what they were originally sold for.

Almost bought a digital scope. But sample rates vary in price and quality of these units. I think you get a better image with the analog scopes that really don't have this requirement, so it is a non-issue with the analog scope.

Hope you get lucky and find yourself a Tektronics 465 in working condition.
Got one - too; got it in trade for an Antron A99 . . .

 

[Captain Kilowatt]

Agreed......the venerable Tektronix 465 seems to almost the standard for hobbyists looking for a good used scope. they are indeed a god scope. Mine was free and was actually recovered from a dumpster in 100% working condition along with the full manual and cart. I have a friend who is an engineer with a well known national broadcaster and they simply throw stuff out when it gets replaced.