154-0652-00

The Tektronix 154-0652-00  (P/N 154-0652-00,154-0652-04,154-0652-05,154-0652-09) is a CRT for the 485.

The part no. 154-0652-00 is the original CRT variant contaning the P31 green phosphor. It was assembled in the 485 oscilloscopes and its variants 485R, 485-1 and 485-2, from serial numbers B010100 to B091499.

The part no. 154-0652-05 is the updated variant of the 154-0652-00, also containing the P31 green phosphor, and it was assembled in the 485 oscilloscopes from serial numbers B091500 and up.

The part no. 154-0652-04 is the first optional variant containing the P11 blue (fast writing) phosphor. It was assembled in the 485 oscilloscopes when Option 78 was chosen by the buyer.

The part no. 154-0652-09 is the updated variant of the 154-0652-04.

According to Gene Andrews, A nanosecond portable oscilloscope (Tekscope Vol.4 No.2, March 1972, p.2+),

The 485 CRT was developed concurrently with the 500-MHz 7904 CRT and uses a similar gun structure. The 8 × 10 division scan (0.8 cm/div) is accomplished by the unique construction of the vertical deflection plate structure. Each plate is a photo-etched box-like structure about 2.5 inches long. The design permits bending the structure to gradually increase the spacing between plates at the screen end. The structure is tuned by means of adjustable compensator plates to maintain a Z₀ of 364 Ω within 1%. A dome-shaped mesh shields the deflection plate area from the high accelerating-anode potential and contributes a two-times deflection magnification. The 21 kV accelerating potential yields a writing speed in excess of 6 div / ns using a P11 phosphor and C-31 Camera with 10,000 speed film.

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Conrad Odenthal designed the high-performance 485 CRT.