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QB4/1100

Sensibly equivalent to:
7527 YL1460
    
Extras ▼

 

The QB4-1100 is a power tetrode for use in AM and FM transmitters from top HF to low VHF and will cover the Band II broadcast band. Output power depends on the modulation used, ie duty cycle, and anode voltage. as an example at 110 MHZ an SSB transmitter with 4,000 Volts on the anode can generate 650 Watts.
Thanks to Sanjay for sending the images of the inner electrode structure.
The central assembly with the anode removed. The filament helix is thoriated tungsten.
The place at which the filament failed.
The top of the screen grid. The modern cage structure harks back to the cage used in the earliest tetrode valves.
The anode and top cap assembly from the broken valve.
The anode screws onto the top cap rod.
The anode corrugations increase the surface area and thus the heat radiating capability.
The open end of the anode showing the substantial thickness of the metal.
The top end of the anode with threaded hole.
The wide glass tube envelope is 87 mm in diameter, and excluding the base pins is 127 mm tall.
Reference: Datasheet. Type QB4/1100 was first introduced in 1960.

 

Pin Connections
1
2
3
4
5
tc
f
g2
g1
g2
f
a

 

Absolute Maximum Operating Conditions
Tetrode
Vh
Ah
Va
5.0
14.1
2.500
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated October 10, 2014.
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