30-11-2020, 06:44 AM
Sorry about brain fade. x1000 gain is 60dB, not 40dB.
DC was achived by restoration rather than a true DC amplifier. Fixed black level was an important part of the M-EMI system. WIthout it, the waste of TX power would have been immense. Using +ve modulation meant you could run the TX into non-linearity on sync pulses, again easing the power requirements.
They did have test equipment, presumably variable frequency generator and AC meter. Doing an accurate voltage divider to measure 2kV over 3MHz BW isn't trivial. They may have had some kind of swept frequency generator to speed things up. What they didn't have back then was any form of standardised time domain tests. Pulse and bar came after WW2.
DC was achived by restoration rather than a true DC amplifier. Fixed black level was an important part of the M-EMI system. WIthout it, the waste of TX power would have been immense. Using +ve modulation meant you could run the TX into non-linearity on sync pulses, again easing the power requirements.
They did have test equipment, presumably variable frequency generator and AC meter. Doing an accurate voltage divider to measure 2kV over 3MHz BW isn't trivial. They may have had some kind of swept frequency generator to speed things up. What they didn't have back then was any form of standardised time domain tests. Pulse and bar came after WW2.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv