524

The Tektronix 524 is an oscilloscope that is designed for monitoring television waveforms. It is a monolithic oscilloscope. It has a thermal cutoff.

Interestingly, the 524 appears on page 33 of the 1966 RCA Test Equipment Catalog.

The 524 weighs 61 pounds and uses 500 watts. It uses selenium rectifiers in the low-voltage power supply. It has a total of 4kV CRT beam acceleration, -1.5kV on the cathode and +2.5kV on the anode. It normally came with a 5ABP1 CRT which has P1 phosphor, but P7 and P11 phosphors were also available.

The vertical signal path of the 524 is similar to that of the 514. They have similar front-ends and similar distributed vertical output amplifiers.

The video trigger circuitry present in the 524 distinguish it from the 514. Just before the L-C delay line in the vertical signal path, there is a cathode follower, V15A, that serves as the trigger pickoff buffer. The resulting trigger signal goes to a video sync separator circuit. Here, the there is clamping and amplification and, most importantly, a non-retriggerable multivibrator. The multivibrator is triggered by the vertical sync of the NTSC waveform. After being triggered, it is not triggerable again for about about 25ms, so it misses the vertical sync of the next interlaced field and instead triggers on the vertical sync of one following that. So it consistently shows the "even" field or the "odd" field. There is a switch that perturbs the multivibrator so it can be switched between even and odd fields. The video trigger circuit drives a conventional trigger circuit and sweep circuit similar to that of the 514.

• Tektronix 524AD Manual (PDF)

• 
• 
• 

  Time Mark Gen for 524