EL34 Tesla Welded plates O-O getter brown base same prod code NIB V50 v51

Description

Here is a pair of Edicron/Tesla EL34 early production tubes. The pair is in original boxes and was probably never used; see pictures and test data.

The Tesla production Double O-getter is, considered as the best sounding Tesla EL34. I refer to the many reviews on the web.

The pair has excellent specs. Both tubes have date code G9LP8. 

The measurement data below show that the pair is in excellent condition. And fully in line with the specification for a new EL34.

Test results*

The measurement data below show that both tubes are in excellent NOS condition. 

Valve 1 V50	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	97 mA           11,6  mA/V OK	=  NOS = NOS
Valve 2 V51	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	112 mA       12,9  mA/V OK	= NOS = NOS

Telefunken measuring values for new unused tubes:

• The rated emission value for a new EL34 is:  100 mA. 
• The rated transconductance value for a new EL34 is:  11 mA/V . 

For Telefunken specs info see last picture 

Test condition & equipment:

Mutual transconductance, plate current, gas and shorts test equipment: AVO Mk IV (Dutch army tester) , AVO Valve Data Manual 23rd edition 1981, RFT stabilised mains, Utracer3+, Philips PE 4832, 2x Korad KA3005P programmable power supply, 2x Keithley 2700 and 2x Fluke 145. 

Test conditions: Ua (plate voltage) = 250 Volts, Us (screen voltage) = 265 Volts, Ug = -13,5 Volts and Uf = 6,3 V ± 3% (factory conditions). Please read our test page.

 

Summarized description