| 
		
		 | 
		
		
			
				
				
		
			
				
				 
				 | 
				
				 
				 | 
				
				 
				 | 
				
				
				
					
						
							| HL4 | 
							All purpose triode | 
							1935 | 
							B5 | 
						 
						
							| HL4+ | 
							low microphony triode | 
							1936 | 
							B5 | 
						 
						
							| HL4G | 
							low capacity triode | 
							1936 | 
							B7 | 
						 
						
							| HL4GS | 
							as HL4G with P base | 
							1939 | 
							P | 
						 
						
							|   | 
							  | 
							  | 
							  | 
						 
					 
					
						
							
								| 1 | 
								2 | 
								3 | 
								4 | 
								5 | 
								
								base | 
							 
							
								| f | 
								g | 
								f | 
								a | 
								
								k,s | 
								B5 | 
							 
						 
					 
				 
				
					
						| 1 | 
						2 | 
						3 | 
						4 | 
						5 | 
						6 | 
						7 | 
						tc | 
						base | 
					 
					
						| s | 
						- | 
						- | 
						f | 
						f | 
						k | 
						a | 
						g | 
						B7 | 
					 
				 
				
					
						| 1 | 
						2 | 
						3 | 
						4 | 
						5 | 
						6 | 
						7 | 
						8 | 
						
						 tc  | 
						
						 base  | 
					 
					
						| s | 
						f | 
						f | 
						k | 
						- | 
						- | 
						- | 
						a | 
						g | 
						P | 
					 
				 
				
				
					
						|   | 
						Vf | 
						Af | 
						Va | 
						Vg | 
						mAa | 
						Ra | 
						gm | 
					 
					
						| HL4 | 
						4 | 
						1 | 
						200 | 
						-3 | 
						4 | 
						11,500 | 
						3.5 | 
					 
					
						| HL4+,HL4G/GS | 
						4 | 
						0.65 | 
						250 | 
						-4.5 | 
						5 | 
						11,000 | 
						3.5 | 
					 
				 
				
				 | 
			 
			 
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