Sensibly equivalent¶ to:
Type EL821 is a video output amplifier used in professional applications for driving TV or radar signals down (fairly) long cables. We do not think that it was much used, if at all, in domestic sets. This exhibit has the later stylised M logo.
Sources specifically list it as a video amplifier. Note the high value of gm, necessary in order to obtain reasonable gain and power output with wide-band signals, and for correct matching of video into coax cable. TV studio equipment racks used to be full of EL821/6CH6s.
The valve is pin compatible with the 6BW6 but they have different uses.
The anode fills the space between the mica discs and no internal details are visible.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins, is 58 mm tall.
References: Data-sheet & 1040. Type EL821 was first introduced in 1962.
Absolute Maximum Operating Conditions¶
PDF scanned from an original document held by the museum
Updated July 21, 2021.