Tektronix 485 vs 2465B

[mtdoc]

2565B shot using entry level DSLR with crappy stock lens.

Ha, way better than my shakey iphone scope photography. 

Is this trace considered fuzzy compared to those sharper Tek 4xx series ?

No not IMO. Sure, an old, in need of recap scope or poorly focused CRT will be bad but otherwise analog scope traces are what they are and I don't get the obsession with slight variations.  On any scope, isn't the question whether the trace is allowing you to see what you need to see accurately? These all allow that.

he RTM3K was clearly specified by people who used scopes every day.

I feel the same way about my lower tier RTB2004. 

[particleman]

The 2465 has a mesh accelerator anode so the focus isn't as good as on the 485 or the 7000 series crts. It's difficult to describe objectively but it's a feature of the 24xx scopes that I never liked. My personal preference would be 485.

The 485 and 7000 and practically anything newer than the last of the 500 series have scan expansion meshes.  The 2465 series, 7104, and the 11302 are the exception as they have box or quadrupole lenses to allow the use of microchannel plate image intensifiers.

But scan expansion is scan expansion whether from a scan expansion mesh or box lens so they all suffer from a larger spot size.  The only model I find it actually noticeable on is my 465 and the sharpest CRT I have is naturally from my 547 with my high acceleration voltage 7000 mainframes which should perform similar to a 485 being close behind and much brighter.  My 2445B might be my "fuzziest" except for my 465 but I suspect both would improve if I used them much like my 7603 improved; CRTs left in storage for years seem to become fuzzy until powered for a couple of days.

Does any of this matter for practical use?  It might if you have a choice.  Otherwise just recognize that high bandwidth oscilloscopes like the 485 have sharper and brighter CRTs than lower bandwidth oscilloscopes like the 465.

The 100MHz 22xx models which replaced the 100MHz 465/465B seem to have better CRTs but maybe the difference is just due to age; I have seen lots of different 22xx models over a long time but only a couple of 465s for a short time.

My favourite is the 2232, at the flip of a switch becomes a DSO and it's got plenty of knobs and buttons including four very handy direct save/recall waveform memories.

I really like the 2232 also.  With peak detection it covers storage applications just fine and the storage display looks much better than one would expect because of the high resolution of the CRT.

My 485 has a very nice clear sharp trace along with my 7633 but do you know what gives them a run for their money in that department? My old 453. It has a much sharper trace than 2213A,2221,465,468.  Don't laugh, but  for the kinds of things I do that is my go to oscilloscope.

[David Hess]

My 485 has a very nice clear sharp trace along with my 7633 but do you know what gives them a run for their money in that department? My old 453. It has a much sharper trace than 2213A,2221,465,468.  Don't laugh, but  for the kinds of things I do that is my go to oscilloscope.

Smaller CRT deflection means less scan expansion yielding a sharper trace but the total area is smaller also.  Wasn't there some variation in CRTs used for the 453/453A and 454/454A oscilloscopes?

You might check to see if your 453 CRT has scan expansion at all since it is only 50 MHz.  To do this, set a slow sweep speed and watch for the "ghost" following, catching up to, and then preceding the spot across the CRT.