The DET19 from M-OV is labelled Osram in this exhibit. It is a low power VHF transmitting double triode that would have been used in push pull with a common tuned anode coil connected across the twin top caps. The HT would be fed into the tank circuit centre tap. The base is ceramic for better resistance to heat and moisture.

We have another valve that carries both the M-OV DET19 and the UK service VT61 designations.

The classic envelope is 43 mm in diameter and, excluding the UX7 base pins, is 110 mm tall.

References: Datasheet. Type DET19 was first introduced^¶ in 1938.

 
Pin Connections

UX7	1	2	3	4	5	6	7	tc	tc
	h	-	g1(1)	k	g1(2)	-	h	a(1)	a(2)

 
Absolute Maximum Operating Conditions^¶

Triode	Vh	Ah	Va	Vg	mAa	Pdriv	Pdiss	Pout	freq	f.max
	6.3	0.8	300	-50	90	1W	10W	15W	100MHz	300MHz

Thanks to Frank Philipse for supplying the above PDF datasheet