May 1854 brought a useful accessory addition to the Mullard High Speed Valve Tester (MHSVT). Developed in conjunction with Messrs. Spear Engineering of Warlingham the range comprised of eight adaptors to facilitate the testing of valves for which no existing valve base was provided on the instrument.
These were precision items, with the bodies of the adaptors being trned from duralumin - usually reserved for aircraft bodies - and just look at the adaptor below for testing the EY51 boost diode - impressive huh?
The adaptors were engraved 1-8 with the figures clearly identifying each adaptor body and were priced at £4. 2. 6d. (£4.125) the set complete in a holding rack. otherwise the adaptors were available idividually at prices ranging from 7s. 6d (37.5p) to 15s. 0d. (75p)