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Osram-GEC Radio Valve Type R4, by Osram-GEC, England, 1917
Inventory Number: 96640
Number of documents: 2
Document Type: Miscellaneous Note
Document Heading: Technical Details
Text:
The R4 was a later model in the highly successful R-type valve series; it carried on the technical developments of the R and R2 valves and was an antecedent of the R5 valve. The R4 valve consisted of a simple heterodyne circuit, and was developed mainly to cover the entire frequency range of the British Admiralty, particularly higher frequencies. This was achieved by changing the size of the threads (compared to previous models) and decreasing the distance to the wire mesh grid, making the construction similar to that of the Type R2A.
Document Type: Miscellaneous Note
Document Heading: Historical Background
Text:
This version is an early example of the R4 valve, probably of late WW1 vintage and made by Osram-GEC before manufacture was moved to Marconi-Osram Valves in the 1919.
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