PT8 TUBE PHILIPS ITALY MRO NOS NIB METAL BASE Post-Röhre 
O GETTER WELDED SLANTED
POSTAL TUBE S TELECOM
RUGGED RELIABLE LONG LIFE MORE THAN 10.000 HOURS
FOR PUBLIC SERVICE PA PUBLIC ADDRESS PROFESSIONAL TUBES
POST & TELEGRAPHS AMPLIFIER S IN POSTAL OFFICE REPEATERS
THOSE TUBES WERE NOT AVAILABLE FOR COMMERCIAL SALE IN THE PAST
FOR THIS REASON ARE SUPER RARE TO FIND ALSO PROPER  DATA TO USE THEM IN THE RIGHT WAY
THOSE TUBES ARE A BIG STEP CHANGE FROM THE OTHER COMMERCIAL AND MOST COMMON ALTERNATIVES , THOSE ARE DEFINITIVE TUBES WITH EXTRA LONG LIFE HIGH RELIABILITY

DIRECT HEATER TRIODE DHT MONO PLATE  DHT MONO PLATE O GETTER WELDED BOTTOM
RED WIRED JACKET
SILVER ROUND PAINT ON TOP  

BIG SILVER PLATE PREAMP

MADE IN ITALY = MONZA PLANT OF PRODUCTION  

HANGING FILAMENT 4 VOLT

MATCHED PAIR  ( TWO TUBES  = 2 PIECES )

CLOSE TO 101F WESTERN ELECTRIC GREAT TUBES FOR PRE AMPLIFIER STAGE AND ALSO FOR " LOW WATTS " AMPLIFIERS AS LAST STAGE AUDIO .

THESE TUBES WERE DESIGNED FOR USE WHERE AS LONG LIFE IS ESSENTIAL.
THIS MAKES IT PARTICULARY SUITABLE FOR APPLICATIONS WHERE CONTINUOUS SERVICE IS DESIRED.
THE MICROPHONIC RESPONSE OF THIS TUBE IS LOW. THE ELECTRICAL CHARACTERISTICS ARE SUCH THAT MODERATE POWER OUTPUT ARE OBTAINABLE WITH SMALL PLATE CURRENTS AND WITH PLATE VOLTAGE UNDER 200 VOLTS.
THE CHARACTERISTICS ARE SIMILAR TO THOSE OF THE No. 101d WESTERN ELECTRIC WHICH OPERATES 1 AMPERE CURRENT,
THE 101F WESTERN ELECTRIC OPERATES AT 0,5 AMPERE CURRENT
THESE PT8 PHILIPS MRO MONZA PLANT OPERATES AT 0,25 AMPERE CURRENTS

HERE DETAILS PT 8 / TS 8
heater Vf = 4 Volt heater
If = 0.25 Ampere anode
Va = 130 Volt
grid Vg = -8 Volt
anode Ia = 8 mA
transconductance 1.3 mA/V plate
R = 5.5K
amplification factor = 7 mA/V
load resistance = 6K

VACUUM TUBE S valve lampe röhre tsf 진공관 真空管 tube valve lampe röhre tsf 진공관 真空管 HAM RADIO audio hi-end hi-fi diy POWER AMPLIFIER Pre-Amplifier Preamp Pri stereo SE Single Ended PP Push-Pull

BOX 72