EL34 Philips Miniwatt Sittard NOS D-D getter pair 1960/1960 v35/v31

Description

Matched pair of EL34 tubes made by Philips in Sittard, Netherlands

Description

Here is a pair of Philips Miniwatt EL34 early Dutch production tubes. The on tube is pulled from a Philips laboratory testing device which was probably rarely used; see test data. One of the tubes is still in original factory box! The pair has excellent NOS specs. 

Both tubes are made in the same week in 1960 !!

Sonics

The Philips Double D-getter is, apart from the metal base EL34, considered as the absolutely best sounding EL34 ever. 

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

Test results*

Valve 1 V31	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	102 mA       12,3  mA/V OK	= NOS = NOS
Valve 2 V35	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	98 mA 12,0  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