307A (VT-225) is Moderate-power, filamentary
suppressor-grid pentode for audio-frequency amplifier or modulator
Class A audio amplifier characteristics
| Plate Voltage | Screen Voltage | Suppressor Voltage | Control Bias | Plate Current | Screen Current | Load Resistance | Input Voltage | Power Output | Second Harmonic | Third Harmonic |
| Volts | Volts | Volts | Volts | mA | mA | Ohms | Peak Volts | Watts | db | db |
| 200 | 200 | 0 | -15 | 36.5 | 3.4 | 4000 | 0-15 | 2.9 | 23.5 | 24 |
| 250 | 250 | 0 | -20 | 50 | 4.0 | 4000 | 0-20 | 5.7 | 24 | 23.5 |
| 300 | 300 | 0 | -30 | 43 | 2.6 | 4500 | 0-30 | 9.1 | 21 | 17.5 |
Limiting Conditions for safe use: Maximum
plate dissipation is 15 watts, screen-grid dissipation is 6 watts,
| 500 | 300 | 60 | 25 |
Filament voltage 5.5 volts, A.C. or D.C.
Nominal filament current 1.0 ampere
This tube works really nice in SE or PP
One of my favorite audio tubes VT225 / 307A
/ 306A, specially
triode strapped and a bit overrated. The National Union version is exact Western
Electric equivalent, with four holes at both ends of plate.
Click to see All 307A VT-225 306A in stock
Hi
I would like to buy 307a tubes for my pre amp.
Regards
Moti
Koliko su vam 307 svih proizvodjaca? Imate li cenovnik, trazim jos vrsta.