Summary

Twin triode designed for use as a cascode RF amplifier in television tuners. Manufacturer: Philips, Hendon, South Australia.

It has a semi-remote cut-off characteristic, making it suitable for use with automatic gain control (AGC). It was one of the first receiving valves to use a 'frame grid', a construction technique which permitted closer grid to cathode spacing than the earlier methods. This resulted in a higher mutual conductance and better noise performance than previous types.

The 'cascode' circuit uses two triodes connected in series to form a grounded cathode stage followed by a grounded grid stage. This produces an amplifier with the favourable noise characteristics of a triode without the need for neutralisation.

This type is known as the ECC189 in the UK and Europe.
6.3 volt indirectly heated cathode.

Physical Description

Tubular glass bulb with exhaust tip at top and standard nine pin miniature configuration.

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