511: Difference between revisions

The 511 was '''Tek's second product''', [[introduced in 1947|introduced in June 1947]]. (The first was the [[101|Type 101 Video Calibrator]].)  

A revised version, the 511A, was [[introduced in 1950]]. [[Howard Vollum]] was directly involved with the design of the 511.   

The 511 was produced with serial numbers 101 to 454.  The 511A has serial numbers 455 and up.

In the 511 there are two power transformers, T1 and T2, both operating on 60 Hz mains power with their primaries in parallel.

T1 produces the CRT anode and cathode voltages, as well as various other regulated and unregulated voltages.   

The CRT cathode and anode voltages in the 511 are simply rectified voltages from the secondary of T1.   

The lack of regulation means that variations in mains voltage results in variation of deflection sensitivity.   

In the 511A, the CRT cathode and anode voltages are produced by a 2 kHz oscillator that is powered by the 511A's +225 V_DC regulated supply.   

This results in vertical deflection calibration that is independent of mains voltage.

Even when ordered without the delay, the 511's chassis was pre-drilled for the delay so that it could be added later, in the field, without drilling.

The delay could be switched in and out of the signal path, presumably to avoid the slight signal degradation the delay causes.