Beschrijving
6AS7G produced by Chatham Electronics/ Tung-Sol in the USA; a matched pair !
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 in the same week (week 39) for the Joined Army and Navy in 1954 and both packed in September 1954. 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.
Note: my tubes are often not the cheapest. But is hard to find better tubes !
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
V13 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
114 /119 mA
7,1 /7,1 mA/V OK |
= NOS / NOS
= NOS / NOS
|
| Valve 2
V14 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
120 /126 mA
7,0 /7,0 mA/V OK |
= NOS / NOS
= NOS / NOS
|
Ia: New is 125 mA. Gm: New is 7 mA/V (see datasheet) 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 | 439 & 439 (1954 week 39) Packed: 9/ 1954 |
| Construction | Black plates, copper grid posts |
| 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 |
