The EHT1 is a high voltage half wave rectifier. The filament connects via the Edison screw. This valve is clearly marked EHT No. 1 and differs in construction from our other example. See alsoEHT1 for full details.
The glass is etched with the Osram name.
The other side of the glass clearly gives the details EHT Rectifier Type No. 1. Our other EHT1 does not have a clear Type reference.
The description of the filament in the literature matches the design of filament in EHT1 ie a spherical style. Here the filament is a single hairpin. Note also the strengthening ridges in the anode that are not present in the other exhibit.
The literature refers to baffles that are seen here but not in the other example.
The balloon envelope is 120 mm in diameter, and including the base pins is 430 mm tall.