6AS7G Tung-Sol Chatham 1954/1955, matched pair, NIB Military box V1/V12

255,00

Highlights

  • NIB !
  • Chatham / Tung-Sol production 
  • two bottom D-getters
  • matched pair
  • coke bottle
  • 1955 & 1954

1 in stock

Category: Tag:

Description

6AS7G produced by Chatham Electronics/ Tung-Sol in the USA; a matched pair !

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

This is a beautifull matched pair of NOS/NIB 6AS7G tubes.They are made by Chatham Electronics; a later subsidiary of Tung-Sol. The tubes are made for the Joined Army and Navy in 1954 and 1955. In the box they are carefully wrapped in a cardboard envelope. 

This version of the 6AS7G is highly regarded for use in OTL amplifiers (e.g. Atma-Sphere) and headphone amplifiers.  I refer to the threads on the web for more information. 

I had the opportunity to obtain a number of these tubes and this enabled me to select a nice matched pair. The tubes have two bottom D-getters with a beautiful flash.The tubes are thoroughly tested. Both tubes have excellent test values that match the factory specification well and balanced systems.

Test equipment & method 

Test equipment:  AVO Mk IV, Utracer 3+, Philips 1532, RFT stabilised power supply, 2x Korad KA3005P programmable power supply and 2x Keithley 2700 and AVO Valve Data Manual 23rd edition 1981. Gas and shorts were tested with: AVO Mk IV. Ia & transconductance are measured conform the official factory specification (see picture) with a cathode resistor. Precision the test voltage ± 1%. Measurement after 10 minutes stabilization. 

Test results*

Valve 1

V1

Ia (plate current):

Transconductance (Gm):

Gas test, Shorts test:

122 /120 mA   

 7,4 /7,3 mA/V

OK

=  NOS / NOS

=  NOS / NOS

 

Valve 2

V12

 Ia (plate current):

Transconductance (Gm):

Gas test, Shorts test:

 124 /129 mA

7,5 /7,4 mA/V

OK

=  NOS / NOS

=  NOS / NOS

 

(Ia: New is 125 mA. Gm: New is 7 mA/V) A valve is assumed to have NOS specs if both; emission and Gm are 90% of the rated value or more.

Please read our test notes and shipping policy before buying !

 

Short description

Tube type 6AS7G
Quantity of Tubes One pair
Brand Chatham/ Tung-Sol
Manufactured in USA
Date codes 647 & 439 (1955 & 1955) 
Construction Black plates
Getter Construction Two Bottom D-getters
Print Condition NEW, See pictures
Box included Original JAN box (see pictures)
Equivalent tubes:  6080, ECC230, 6AS7GA
General test results  NOS

Additional information

Weight 50 g
Dimensions 15 × 3 × 3 cm