EL34 Tronal NOS specs matched pair same code v70/64

Description

Here is a pair of Tronal EL34 tubes; most likely a selection of RFT Germany. The RFT EL34 is known as an excellent sounding EL34 with o longs “life”. They deliver superior sonics compared to the Chinese and Russian new production EL34. 

The pair has NOS specs. The measurement data below show the pair is matched. And fully in line with the specification for an EL34.

Note: my tubes are often not the cheapest.But is very hard to find better tubes !

Test results*

The measurement data below show that both tubes are matched. 

Valve 1 V64	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	106 mA           11,0  mA/V OK	=  NOS % = NOS%
Valve 2 V70	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	103 mA        10,9  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.

*Please read our test notes !

Summarized description

* Specified measurement data

I give no garantee on measurements or different values measured on other tube testers or analysers. Just in case of mismatch of “standard” values of the different tube testers “standards”. My test results refer to tube data sheets provided by the original tube producers. (You’ll find them easily on the web.) And are measured with the specified test equipment.