| .jpg)  | 
				 Dual-grid tetrode Introduced in 1931 
					
						
							| Vf | Af | Va | Vg | mAa | ra | gm |  
							| 2 | 0.06 | 20 | -1.5 | 3.5 | 4500 | 1 |    | .jpg)  | 
				
					
						|  |  
						| 
				Full-wave rectifier |  
						| Introduced in 1932 |  
						|  |  
						|  |  
						|  |  
						| 
					
						| Vf | Af | Va | mAa |  
						| 4 | 1 | 2 x 
						300 | 60 |  |  
						|  |  
						| 
					
						| Equivalent | 6, 506, 4619, 
						B, D3, DW2X, G1054, G214,  G490, 
						KL74301, P2,
						PV495, R233, 
						RGN1054, U10, V, 
						V2, W6 |  |  |