Manufacturer: RCA Victor 1947 Production, Glass etched 'I7M' under Octangle 'Stop Sign' inside is
etched 6B4G -Triode Power Output Vacuum tube
( Vf : 6.3V , If : 1.0 Amperes).
Condition : Found Out of Box and Used Tested Very Good for Gm&mA. Clean Glass, Locator and Pins,
Plug-in and Play Condition.
Note that ALL Versions of TV7's will test tubes at a maximum of 150VDC Plate Supply Volts and 135VDC Screen/Grid Volts. After testing many 6B4G tubes on a TV7 at a lower 150V Plate Supply Volts a
Factory new NOS Bogey will read on average(middle point +/-10%) will be a TV7 meter reading of 76=3,900 uMhos Transconductance(Gm) at 40.0 mA Anode Plate Current emissions zero signal .
The Minimum Good Value (60-65% tube life) TV7 meter reading of 38 = 1,900 uMhos (Gm),
For more technical details please read the detailed desc. below and see all the pics from the data sheets and graphs.
This tube tested NO Shorts, NO Gas, NO Leakage, NO Microphonics detected.
Tube 1: ( Etched in Glass 'I7M', Production 1947 RCA Victor 6B4G Tube Silver ink
on Base "RCA Victor", small RCA Globe, "Made in USA" "8 35"= inked in 1948 but made in 1947 )
TV7 meter reads 62.1/38(min good) = 3,105 uMhos(Gm) at 31.9 mA Anode Plate Current emissions
A printed copy of this detailed description and test results will be included in the box shipped.
More Tech Details:
TV7D/U tested at against Vintage Tung-Sol & RCA Factory Data Sheet specs(dated 1938/40) for Readings of Gm & mA.
Physical Characteristics:
Tube/Valve Type: 1947 RCA Victor 6B4G (ST-16 Shoulder Shaped 'Coke Bottle' Glass Tubes) Triode
Power Amplifier Output Vacuum Tubes. Smoked Glass, Made in the USA.
- Two 4 sided with rounded edges shaped Mica Wafer/Spacers"
- Thick metal rods, Two Hanging upside down "VV" helix Filaments with 4 wires across the top mica wafer spacers
connecting to the metal support rods
- 45%+ 360 degree Silver flashing above the Black Micanol base
- LARGE Hexagon 6 sided Metal Foil Getter
Out Test set : Recent( 07/24/2023) Dan Nelson Restored, Upgraded and Calibrated TV7D/U with Digital Meter reading
Transconductance(Gm) and Anode Plate Current emissions.
REFERENCES: Tube type 6B4G 'Bogey' (=Vintage Factory new from Tung-Sol(1938)/Sylvania from Data Sheets)
-see pics of Data Sheets for more Technical Specs on this Tube type.
Transconductance( Gm) depends upon Plate Supply Voltage when testing
Tested in Class A1 Single Tube (Lowest THD)
- Standard 'Bogey' Tested at Plate Supply 250VDC with Grid Voltage of -45V is
= 5,250 uMhos Transconductance(Gm) at 60.0 mA Plate Current Emissions.
- Power Output Dissipation For Class A1 (One Tube)
Single Ended Triode 3.2 watts with Amplification factor (Mu) 4.2 .
- Class AB1 with Fixed Bias 325V Plate Volts at -68V Grid Volts (2 Tubes in Push-Pull, most common use)
= 15 watts Power output dissipation at 2.5 THD, with Zero Signal Plate current = 40mA.
Note that ALL Versions of TV7's will test tubes at a maximum of 150VDC Plate Supply Volts and 135VDC Screen/Grid Volts. After testing many 6B4G tubes on a TV7 at a lower 150V Plate Supply Volts a
Factory new NOS Bogey will read on average(middle point +/-10%) will be a TV7 meter reading of 76=3,900 uMhos Transconductance(Gm) at 40.0 mA with zero signal .
The Minimum Good Value (60-65% tube life) TV7 meter reading of 38 = 1,900 uMhos (Gm),
For more technical details please read the pics from the data sheets and graphs.
WE PACK VERY WELL FOR SAFE SHIPPING WORLDWIDE,
WE SHIP FAST. MANY YEARS EXPERIECE SHIPPING FRAGILE TUBES AND VINTAGE FRAGILE ELECTRONICS
AND SPEAKER SYSTEMS.
Tube specs 6B4G Vf : 6.3V If: 1.0 Amperes - Power Output Dual/Double/Twin Triode
Country: United States of America (USA) | |
| Identical to | 6B4G = 6С4С = CV851 = 6B4 |
| Similar Tubes | Other base: 6A3 |
| First Source (s) | 26.May.1936 : Electron Tube Registration List |
| Predecessor Tubes | 6A3 |