Brimar was established in 1922 and during their existance they have been part ofmany companies including: Edison Swan Electric, Cosmos, Mazda, Baird Television, Ferranti, AEI, EMI, Thorn, Marconi and The Rank Organisation.
Brimar has always been a technology led company as their varied technical achievements show:
Here we have a single 10E/373 an AIr Ministry military specification U52 DIRECTLY HEATED TAPE FILAMENT rectifier manufactured by Osram at their Hammersmith Brook Green factory sometime during the war years.
This valve shows excellent bright getter and has the inverted getter pan situated down by the glass pinch, however, more importantly it tests as EXCELLENT using my Avo VCM163 valve tester. This exquisite device carries good white print, the classic U52 envelope shape and the trademark rounded black low loss micanol base - simply super.
Device test data: Ia = 120.0mA for both diode sections.
Device specification 120mA delivery for both diode sections. So you can see we have 100% emission from this venerable beauty.
On offer we have a beautiful matched pair of 18mm, 'long plate' white print STC Brimar 12AU7/ ECC82 carrying identical factory codes of 1413. These devices present with superb matching both within the envelope and inter device.
These devices have tested on our AVO VCM163 valve tester as having nominal emission with very close matching for each triode section within the envelope.
A21: Section 1: Ia = 10.5 mA; gm = 1.9 mA/V
A21: Section 2: Ia = 10.5 mA; gm = 1.9 mA/V
A22: Section 1: Ia =10.0 mA; gm = 1.9 mA/V
A22: Section 2: Ia = 10.0 mA; gm = 2.0 mA/V
The specification for a new/100% emission valve is:
Ia = 10 mA; gm = 2.2 mA/V
As you can see, this result show a really strong matched pair of valves with good matching of each triode section within each envelope.