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547: Difference between revisions
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proofreading
Vintage dave (talk | contribs) m (LVPS regulator section is all tubes) |
Vintage dave (talk | contribs) m (proofreading) |
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Both center-tap and bridge configuration is used. The regulator section uses no transistors, only tubes. | Both center-tap and bridge configuration is used. The regulator section uses no transistors, only tubes. | ||
There are multiple 6.3V secondary outputs for heaters, | There are multiple 6.3V secondary outputs for heaters, | ||
some elevated to different voltage levels based on the section/tube it's used for to keep the Heater-Cathode voltage level within limits. | |||
As is common in many Tektronix scopes, | As is common in many Tektronix scopes, | ||
all regulated voltages are referred to the negative regulated rail (−150 V in this case) by fixed low-tolerance dividers. | all regulated voltages are referred to the negative regulated rail (−150 V in this case) by fixed low-tolerance dividers. | ||
Only the −150 V voltage is trimmed | Only the −150 V voltage is trimmed; its reference is a [[OG3]] VR tube. | ||
A [[12AX7]] is used as the comparator and two [[6CW5]] in parallel are used as series pass tubes. | A [[12AX7]] is used as the comparator and two [[6CW5]] in parallel are used as series pass tubes. | ||
A [[6AU6]] is used as an error amplifier. | A [[6AU6]] is used as an error amplifier. | ||
Most other power supply sections in the 547 replicate the same basic design, | Most other power supply sections in the 547 replicate the same basic design, | ||
except slight changes in tubes used | except slight changes in tubes used: the +225 V and +100 V regulators employ a [[6080]] as the pass element, and +350 uses a [[6CW5]]. | ||
The plate voltage delay circuit is similar to that found in many may other | The plate voltage delay circuit is similar to that found in many may other Tek scopes of the same era. | ||
A 6N030 delay tube (P/N 148-0021-00) controls a relay that switches plate supply voltages on only after the tubes are warmed up. | A 6N030 delay tube (P/N 148-0021-00) controls a relay that switches plate supply voltages on only after the tubes are warmed up. | ||
Heater voltage is applied to all tubes immediately when the power switch is turned on. | Heater voltage is applied to all tubes immediately when the power switch is turned on. | ||