Valve Announcements and Adverts

These are some adverts that were published in 1950s technical magazines:


First of all, for all the KT88 fans, here is the original announcement of the KT88. Notice that the anode dissipation is 35 watts not the 42 watts of later models. The envelope appears not to have the distinctive 'bottom shoulder', nor does the base have the metal ring. I'm not sure if this is artistic licence or whether the first ones were really like this?

KT88 advert

(click the image for a high-res version)

12AX7/ECC83, 12AU7/ECC82, 12AT7/ECC81

I had a discussion with Ned Carlson about whether the ECC83/12AX7 was a U.S. or U.K. invention. I had always assumed that it was a Mullard design - Mullard ones were always regarded as the 'real McCoy' here in the U.K. Ned was right of course! - here's the proof that even in the U.K. the 12AX7 was the first.

This is a Brimar advert from February 1950.

Brimar 12AX7 advert

(click the image for a high-res version)

These were probably imported from the states and relabelled by Brimar.

This is the Mullard announcement from October 1953.

Mullard ECC83 advert

(click the image for a high-res version)

Mullard did have the ECC81 about 9 months earlier.

Andy Cowley, April 2002.
Updated by DWK, 19th Sept. 2013.