Ediswan

1F2 / DF92 / 1L4

9.00 USD

Very rare antique BVA (British Valve Association) miniature glass pentodes. Manufactured in England by Ediswan Limited (Siemens Germany/Edison USA/Swan England), an AEI Company (Associated Electrical Industries). 7 pin miniature tubes with top D-getters have printed on them MAZDA VALVE 1F2 1L4 MADE IN ENGLAND P - B.V.A. Tubes come complete with as new corrugated cardboard and paper rolls, also copyrighted BVA garantee sheets, and blue and red Ediswan boxes. Price indicated is 10 shillings plus purchase tax !

Condition

Tube Matching
Tube Matching
6.00 USD by tube

WHY ?

A tube may have one, two, or three internal sections depending on the purpose of the tube; somtimes these sections are all the same, sometimes they are different. Due to manufacturing and material tolerances, there may be slight differences between the original specification and the actual tube. Tube matching tests each one of these internal sections and selects tubes, compared to original specifications at manufacture, for balanced performance and good sound.

HOW ?

All our tubes are tested by us prior to packing on our Stark, AVO, Simpson or RF Laboratories Inc. calibrated testers. On request for tube matching, tubes are matched for Mutual Conductance in Micromhos and Plate Current in Milliamps on our Amplitrex or Radioelec Duovac testers, with results printed for each  individual tube. Certain tubes difficult to test are matched for Mutual Conductance in Micromhos only on one of our regular calibrated testers. On request we can also test for Microphonics.
Quantity

Ediswan
6 Items

Data sheet

Base
7 pin miniature B7G
Boite type
2/1
Emplacement
32
Quide
354
Fonction
Pentode