>
>Thanks for Mr.Egen, Karlsson and Perzonka, for yours attention to my
>problem, by the way, almost old version Grounded Grid Amplifier using zero
>bias in their cathode, I don't know what limitation happen in a few years
>ago, so how to determine the class service of this GG amplifier either AB1,
>AB2 or class B ???. but recently almost every GG
>Amp. design using diode zener for cathode biasing, my question, how to
>determine this zener voltage for various tube that available in the market.
>
? For thoriated tungsten fil. tubes, Zero Signal Anode Current is
roughly 20% of max. rated anode-current. For oxide-cathode tubes, ZSAC
is typically about 10% of anode-current. In both cases, since the
actual bias V depends on the amount of anode voltage supplied to the
tubes and actual Mu, you need to test each tube to determine the correct
bias V at the anode supply V you are using. . .
. A rugged means of obtaining an adjustable bias V source is a string of
forward biased 3a rectifiers connected to a rotary switch. Each diode
provides approx. 0.7V drop.
- cheers, Firson
- Rich..., 805.386.3734, www.vcnet.com/measures.
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|