Beschrijving
This is a 12AT7WA (ECC801S) tube made in 1963 by Radiotechnique in France. Rare tube!
Description
La Radiotechniques was at first (1919 – 1931) a subsidiary of the French Compagnie générale de la télégraphie sans fil (CSF). Later (1947) it became a subsidiary of Philips of the Netherlands, who also owned Amperex and Mullard.
This tube has a double post halo getter and copper posts. It has a very solid construction; even the halo-getter is reinforced (see pictures)! The tube date code is FRS 63023; 1963. Most likely manufactured in the 23th week of 1963. The 12AT7WA is the longlife, tight tolerance version of the ECC81/12AT7. This version was made exclusively for governmental institutions and manufacturers of high precision gear.
I have no information about the sonic properties of this tube.
The tube is thoroughly tested. The tube matches the factory specifications. The has balanced systems. See test results in the section below.
Test results
Test methods and test conditions are outline on the tube testing page.
The measurement data below illustrate that the tubes are in good condition.
| Valve 1
V99 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
9,7 / 9,1 mA
5,8 /5,6 mA/V OK |
= NOS / NOS
= NOS / NOS
|
Where NOS is : Ia = 7,0 to 14,0mA, Gm= 4,5 to 6,5 mA/V.
(Telefunken factory specification see test page)
Summarized description
| Tube type | ECC81 |
| Quantity of Tubes | One tube |
| Brand | Dario |
| Manufactured by | Radiotechnique, France |
| Date code | FSR 63023 |
| Plate Construction | Copper grid posts |
| Getter Construction | Double post halo getter |
| Print Condition | See pictures |
| Box included | Generic box |
| Equivalent tubes: | 12AU7, ECC802S, ECC82, 13D8 , CV4003, CV491, 5814 , 7730, 5963 |
| General test results | NOS |
Please read our test and shipping policy before buying also !
