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Nederlands Forum over Oude Radio“s |
Re: FDD20
Geschreven door Jacob Roschy om 08. Jul 2002 22:44:11:
In reactie op: FDD20 geschreven door Frank Philipse om 30. Jun 2002 16:38:58:
Hallo Frank,
the Brans Röhren- Vademecum, German edition from 1947, tells us about the FDD20:
Heater: 12,6V, 0,35A,
Ua = 250V; Ug1 = -5V; Ia = 6mA; µ = 33; S = 3mA/V; Ri = 18 kOhm,
data given are obviously for both sections in parallel.
I'm surely convinced, this tube is the same as the well known 6N7, only base and heater ratings are changed.
FDD is correct, but to use the number 20 for a P- base- tube is pretty strange, this may be one of Philips' caprices.
The data given in :
http://ourworld.compuserve.com/homepages/jlvillabona/hoja-f2.htm are obviously wrong, particularly the heater ratings, the base diagram seems to be OK.
Good luck,
greetings from St. Ingbert, west- south- west Germany,
Jacob