[Boatanchors] Oscilloscope Recommendations

[WQ9E at btsnetworks.net]

Rob made excellent points about shipping and not being intimidated by controls.  Scopes, particularly larger ones, are easily damaged if not packed properly.  

My first exposure to Tekronix scopes was when I was 8 or 9 and my father taught me how to calibrate them including the tedious calibration of L/C delay lines that were later replaced by coaxial delay lines in analog scopes.  Although a 70s/80s/90s vintage "lab grade" scope can look intimidating to operate the learning curve for basic measurements is very flat and fast.  Tektronix manuals are excellently written and easy to follow, even those from the 1950s.  I am biased towards Tektronix and use a pair of 7854 scopes as my main bench scopes but I also have a few much earlier tube type Tektronix scopes including a pair of energy consuming 555 and 556 true dual beam mainframes.  Although I am very much an analog scope fan I did pick up a mint condition Tektronix TDS-210 digital for $50 and realistically it will make 95% of the measurements I need in a package that is small and light but there are times when I need the specialized plug-ins of my 7000 series scopes.

One caution when buying is to consider that older analog scopes with a lot of hours on them may have a weak CRT.  If you have a chance to try it out in person before buying the trace should be visible not long after the intensity control is moved from the full CCW position and it should continue to increase in a steady fashion as you turn it further clockwise but do NOT leave it at high brightness for any period of time as you will burn the phosphor.  If the intensity is slow to increase and then tends to rise rapidly and bloom near full intensity setting it could be a power supply issue but there is a good chance that the CRT is nearing the end of its emission life.  The presence of phosphor burns is something else to look for, discolorations from phosphor burn can be seen if you look at the screen closely.  Although phosphor burn doesn't prevent the scope from working those burn marks will be dead areas on the CRT and it usually indicates with a lot of hours by a careless or untrained user.  

In general I wouldn't consider an older storage type scope for my main bench scope because most of the time you don't need storage and the storage CRTs and supporting circuits are more complex and CRT life is shorter.  I do have a multimode Tek storage scope I use with my spectrum analyzer plug-in and I sometimes use the waveform storage feature of the 7854 scopes but need for a storage scope is rare and you can accomplish almost anything you need these days using a digital camera for storing displays.

Rodger WQ9E