Oscilloscope Probes

[JC]

Just so you know, the length is due to the length of the CRT, and the length of the CRT is as long as it is to keep the deflection of the cathode ray as low as is practical.

Deflecting the CRT in order to direct the trace to the screen naturally introduces some error in the accuracy of where it lands; the less you have to do, the better.  Same reason that CRTs used in serious broadcast monitors for TV stations were as long or longer than your scope.  We are more used to CRTs for home use, where they trade off accuracy for making the depth of the product shallow enough to be acceptable in your living room.

Take heart, though!  When I was in school, we had "lab" scopes that came built onto their own wheeled carts and took two guys to lift!  Yours would have been considered to be a compact model!

[Grainger49]

That looks like the 1950s vintage Tektronics that I used in school.  No, they were old scopes when I was in school.

The key for us to get good measurements was to plug it in and get it warmed up immediately.  Also, we calibrated the probes every time we started to take measurements.

[dbishopbliss]

I turned it on and I get a green dot on the display.  Actually, it didn't start out a dot, but I turned the FOCUS and ASTIG knobs until it became a dot.

Then I was able to use the DC BAL POSITION knobs to move the dot up and down and another knob (LEVEL I think) to move it horizontally. 

I will try making a lead and clipping it to the heaters tonight.  I assume I clip one lead to ground and the other to one of the heaters. 

[JC]

Hopefully, you can turn that dot into a horizontal line by playing with the sweep or "Time Base" controls.  

It also looks like you may have a "Cal" signal you can play with, up in the upper right quadrant; can't quite read it, between the "Scale Illum" and "Astig" controls.

[dbishopbliss]

I made a diy probe from an interconnect that came with an old dvd player, an rca to bnc converter and some alligator clips. 

I clipped it between ground and one of the heaters and was able to see a sign wave.  There is no scale so I'm not really sure what it was telling me by looking at the wave.

I also connected it to the output of a cd player and got lots of pretty waves.  I'm guessing that is good.

Finally, I clipped the leads to each end of a 1000uH axial choke and held it near a power transformer to see if I could induce some current... I did.  I had to have the 'scope on the most sensitive setting to see anything, but it went from a straight line to a wavy line when I got near the laminations of the transformer.  The waves got smaller when I was on the bell side of the tranformer.  I also noticed a change if the size of the wave depending upon how I oriented the choke.  I guess I can use this to determine where to place my chokes, although I'm not sure how a axial choke (size of a 5W resistor) corresponds to a larger hammond-style choke. 

I went ahead and ordered some 60Hz leads.  I figure I can always use them on another scope if I decide to upgrade later.