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503: Difference between revisions
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other than the two filament circuits which are | other than the two filament circuits which are | ||
supplied by the AC mains power transformer. | supplied by the AC mains power transformer. | ||
It is basically a tube switch-mode power supply. | It is basically a tube switch-mode power supply (SMPS). | ||
A [[6DQ6]] power pentode | A [[6DQ6]] power pentode, V620, feeds switched primary current | ||
The | to transformer T620. | ||
The switching frequency of V620 is between 25kHz and 30kHz, | |||
enabling T620 to operate efficiently with much lower core mass | |||
than would be required for a transformer operating at mains | |||
frequency. | |||
A main virtue of the 503 is its low bandwidth which enables it to operate at high sensitivities while not responding to interference from broadcast transmitter RF fields and is therefore useful for biomedical experimenting as well. | A main virtue of the 503 is its low bandwidth which enables it to operate at high sensitivities while not responding to interference from broadcast transmitter RF fields and is therefore useful for biomedical experimenting as well. | ||