I bought a Sound Technology 1510A tape recorder test analyzer that can automatically do frequency response, 2nd and 3rd distortion, signal to noise, channel separation, check playback head azimuth, wow and flutter and store data in a digital memory for comparison. Previously I had to make dozens of individual frequency measurements, then convert the voltages to dB and hand draw a graph. This device can do all of that and so much more with a built in test procedure. Fortunately it comes with a well written operator's manual and I'm still learning. I needed two Magnetic Reference Laboratory test tapes to do some of the tests, they should get to me on Friday.