R69

John Koster: As far as we know, this Dario tube (Trigrille) has only been made for a year, with a rather dubious 1st grid. The tube has four pins and two extra pins at the side, one for the first grid and one for the 3rd grid. The additional G1 (connected to a positive voltage) was supposed to give some extra emission by reducing the space charge around the filament.

Péricaud used these valves in some of its Trisodyne models as some sort of unique selling stunt, but in fact it was all "humbug", and production stopped after a year... To overcome replacement problems, the valves could easily be substituted by a normal "bigrille" without loss of functionality. Of course with some modifications, even a simple triode can be used as a Tropadyne Mixer/Oscillator.

The DARIO data-sheet shows a different pin configuration as STANDARD!.

The tube is not listed in any of the usual reference books.

R69: John Koster John Koster
R69: John Koster John Koster Segue ...	Just Qvigstad	R69: DARIO / v.d.Elst Wolfgang Holtmann Segue ...

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