Description
Here is a matched pair EL84 tubes made Matsushita in Japan.
Detailed description
This pair of EL84’s is produced by the Philips subsidiary Matsushita in Japan. The tubes have been thoroughly tested and have excellent electrical values (note test results below). Very strong tubes! Please not that the Matsushita EL84 tubes are not provided with an etch code!
Matsushita
In 1952 Konosuke Matsushita signs a technical cooperation and licensing agreement with Philips in the Netherlands. As a result Matsushita obtained it’s tooling, tube technology and materials from Philips. A lot of Matsushita tubes look like Philips and Mullard tubes at 1st glance. It should therefore come as no surprise that Matsushita made excellent tubes. Matsushita tube production started in 1953 and ended in 1979. The circular Matsushita logo changed in about 1969 to a triangle.
Test method
Mutual transconductance, plate current, gas and shorts tested with: AVO CT-160 (Dutch army tester), Utracer3+, Philips 1532, RFT stabilised power supply and 2x Keithley 2700. Test conditions: Anode 250V, Screen 250V, Grid -7.3V, Filament 6.3V, Rated Ia = 48mA, Gm = 11.3 mA/V. AVO Valve Data Manual 23rd edition 1981 Before testing they were burned in for 48 hours.
Test results*
The measurement data below show that the tubes test NOS and are matched.
| Valve
V17 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
48 mA
11,3 mA/V OK |
NOS
NOS
|
| Valve
V30 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
45 mA
11,0 mA/V OK |
NOS
NOS
|
* Please read the test notes !
Summarized description
| Tube type | EL84 |
| Quantity of Tubes | One pair |
| Brand | Matsushita |
| Manufactured by | Takatsuki or Kyoto, Japan |
| Date code | 5D (1965) |
| Plate Construction | Grey plate |
| Getter Construction | Halo getter (see pictures) |
| Print Condition | Bad; see pictures |
| Box included | Generic boxes |
| Equivalent tubes: | CV2975 6BQ5 7189 E84L |
| General test results | NOS |
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