A Philips full-wave rectifier from the first years of the mains receiver, in the wire gauze anode construction that radiomuseum records as a distinct variant of the type. It goes under four different numbers depending on whose catalogue you are reading, which is worth knowing before you go hunting for a spare.
Tested very strong on a Tesla BM-215A, reading well above minimum with both rectifier sections balanced against one another.
1823 = 506 = RGN1054 = G1054
Normally replaceable, slightly different: G214, G490, PV495, R104, R233, V6, P2 Longlife, S2 Megatron. Heater differs: DG102.
Radiomuseum notes that some examples of this valve carry both numbers on the same glass, 1823 alongside 506, the latter being the earlier Philips designation. If you are searching for one, try all four numbers.
Note: the filament is directly heated and draws a full amp at 4 volts, so it wants its own transformer winding. Check the supply before fitting it to anything that was not built around it.
Philips listed the 1823 from 1927, and it went on to become one of the workhorses of the early mains receiver: radiomuseum records it in two hundred and ten models, with 1934 alone accounting for forty-one of them. The filament is directly heated at four volts and a full amp, sitting on the four-pin European base standardised back in 1914. Under other catalogues the same valve is the 506, the Telefunken RGN1054 and the G1054, and that last connection places it precisely in the story: the RGN1054 is the type Telefunken replaced with the RGN1064 in 1932. What sets this one apart is the construction. The anodes here are wire gauze rather than solid sheet, a form radiomuseum lists separately as a variant of the type, and it is the version collectors of early rectifiers go looking for - partly because you can see straight through the electrode structure, and partly because gauze anodes were abandoned long before the type itself went out of production.
Gauze anodes you can see straight through, both halves in step, and ninety years behind it - one for the early-set restorer.
SKU: 608