Venture's 6-300BX specification
Filament voltage: 5 V
Filament current: 2.5 A
Anode voltage 500 V
Anode dissipation 75 watts
Cathode current 200 mA (self-bias),
140 mA (fixed bias)
Input cap. 9pF
Output cap. 4.5 pF
Capacitance between Anode and Grid: 15 pF
Ua: 300 V
Ug1: -60 V
Ia: 90 mA
Gm: >= 6mA/V
Ri: 600 Ohm
Amplification Fact.: 3.85
Pout: >=20 watts
Application & Modification Tips
- Filament voltage: 5 Volt
- Filament current: 2.5 A (the AC power transformer that's provide the filament current should be able to supply minimum the current of 2.5A; it should be provided at least 3A for one tube)
- Output transformer primary: 2000 to 2300 Ohm
- When use fixed bias, then apply 220 Ohm 100 watts resistor (provide good cooling). So if the voltage reading is 22 volt on the resistor then the current Ia is 100 mA.
Use a very good quality resistor.
- On the input grid, use 47 K ohm as input resistor.
450 to 500 volt should be the best for the tube.
- Output transformer should design for 25 to 30 watt output.
- In case of a small power OPT was used, then reduce the bias current accordingly, also use lower Ua (ca. 400 V). The bias current should depend on the OPT. The output power will be less.
- It is most suggested to use a higher power OPT at least 20 watts.
* The 6-300BX is not direct replaceable to conventional 300B
* Make sure of applying proper volt according to the manufacture's specifications, we will take no liability for damage caused of any type while your modification.
Last updated on 2/19/04