Model 465 and 2430 and 2430A. Not affiliated with Tektronix but old logo's used with permission!
I do not own any tube based scopes, nor desire to own them ever again., CRTs are always cool.(aka, CRO's)
This page shows calibration for low tech work, not NASA work or CERTIFIED work of any kind...
Like a Ham radio operator, or a service tech, working low tech, low end (low price for old schoolers) gear.
Low end to me, means I can fix it, and High end means I need a bloody NASA engineer to fix it then a $500 cal-lab fee later.
At no time am I doing NIST.gov level standards here, this is just HOBBY levels... and accuracies, ( and costs of owner ship)
The CRO scopes (means CRT) , all are easy to fix, if broken. All Tek scope are until they started adding magic chips. (tunnel diodes, custom hybrids, etc)
But if the scope is cheap and works, all Tek scopes are BUY !!!
The 2465B scope is very popular. Many tek scopes the BW is 2 times the stated bandwidth, (TEK quality is serious here) but it does have hybrids, <(unobtainium rare)
if this scares you drop down to 22xx scope series, the older the scope the less unobtainium. But really if it's only $100 why worry.?
Still not sure what 2 scopes to own (takes a scope to fix a scope so.. check out the TAS series. 465-up!) See this the wiki.
I have no opinions on best, each person has his/hers own needs , cost , bandwidth or performance features.
I have 3 pages covering 3 scopes;
WHAT ARE GOOD USES FOR A SCOPE? (O'SCOPE, DSO)
Working with out a scope is near impossible, for the serious problems we face. (noise, hum, glitches, timing,etc)
Electronics technology is very diverse. (DC to Daylight as we call it)
No one scope does it all, save a few $50,000 scopes (maybe) so pick a scope that matches your needs.
Below are some Ideas on how to use a scope. A simple list.
The first rule of being a technician is , is your scope overloading the circuit (RF mostly) , so that causes wrong readings. (use a high Z probe and low parasitic capacitance probe. 10:1 or 100:1 ratio.
What are the rules for this signal you are trying to measure, the circuit impedance low or high , and freqency or even rise times expected.
The answer to that is easy, read the service manual for the system under test. (or the chips themselves)
The Scope can find very easy, the following problems, in circuits:
- Noise. Lets say a too high ripple noise in a DC
supply. (or in vehicle, noise from the Charging system , or
spark,etc...?)
- You can Check all analog signals, up to the bandwidth of
your scope. Yes, chips come in Analog, digital the latter are
called DSO.
- Digital
signals too weak?, not going low enough or not high enough or
shifted to
illegal bounds. (VIH/VOL, VIH and VIL) or gross over shooting or even
latch up events.
- You
can measure live data from most sensors, like the photo below, or the
RF output from a HAM transmitter, any radio with matching
bandwidths.
- It can see bad grounds , at sensor inputs, we call this
ground bounce, in digital signals.
- When using a DMM volt meter, it averages signals, (a kinda
lie) and you miss out on what is really happening. The scope
shows real time signals. What you see, is what you have !
- On more expensive DMMs they do have capture Min /Max, but
is
very limited in accuracy, it only works for slow signals. (slow sample
times , misses most glitches)
- My storage DSO can store, just what happened last. (you
can capture signals that are rare or catch an aberration for analysis.
) Finds Fast nasty Glitches.
- The Scope shows you the truth. (in all its glorious
bandwidth, like watching 3D TV the first time)
- In every case, of unsolved problems, my scope and my
analog data logger , found the cause. Every time. Newer
scopes have a signal logger built in.
- By Glitch, we mean a fast moving, illegal, voltage or current aberration or transient, Glitch is easier to say, no?
- One can use a current probe on this scope and
see dynamic
current signals or problems.
- Additionally we can use differential probes, for checking ,yes,
differential drivers or receiver inputs.
- The Scope can be used with high voltage probes or used with
special low capacitances probes for tuning RF filters, and the
like !
- Find a bad power supply that has bad ripple at 60Hz or
120Hz. Bad filters in the power supply.
- Find a power supply that oscillates. (old analog supplies can do that, any amplifier of any kind can go into an illegal oscillatory state,(negative feed back problems?)
- Find bad filters in a switch mode power supply, SMPS, (RF noise)
- and
more. , my new scope has a DMM (virtual) and Freq, counter built in the
software. I can replay my last readings and even change X /Y scalings
after the fact. I can store the screen to a file.
I have set up this older 1980 scope to catch glitches, that are very random and it will do the job. ( a dark room helps!)
You can arm the trigger ("Single Sweep"), and wait for the signal, and BANG. Practice and you can too. The trace will die away fast, but you saw the glitch.
Hard pressed one day ,we used a camera (lights out) , 2 guys to photo that 1 time event."Polaroid" (we didn't have the storage scope option , very expensive $$$ back then , late 80's)
Today 10x more easy this is.
The real DSO scope is the far better one, to do the capture and look, after the fact.
In the world of electronics, not all problems are simple , like DEAD or inactive. (noise , glitches and weak, timing is wrong)
Not all problems go away with parts or card swaps and guessing .
Sorry but that is reality, and reality is that digital fails for analog reason too, like bad VIL level for logic chips, or VIH. (or a bad pull up resistor seen on Open drain transistors)
I have seen circuits cards fail, in fact, a specific chip on one board, caused by a noise being generated, far away on some other board or device in the system.
Only a scope finds these levels of problems. (or bus line ringing due to bad line matching resistors) etc...
If doing development work, (test jig, prototypes, breadboarding, etc) you also validate your signals, using a scope or for doing debugging of a new design.
One more tech rule , we check all power supplies first, for levels then noise/ripple. (or you just might waste the whole day beating our head on the wall)
end usage.
rev 17++++ 8-27-2013 (last edit, 9-6-2016) revised again Jan,29-2018 (battery swaps)
I'm on Eham.net, K5JXH.