The 3CX2500A3 and TH5-6 are metal ceramic forced air cooled triodes with thoriated tungsten carbide cathode. The filament and the grid are in a coaxial structure with low distributed inductance, the operating frequency can reach 110MHz, and the anode dissipation power is 4kW. It’s intended for FM, AM, TV equipment and industrial heating equipment. The core column of TH5-6 has a radiator, which improves the cooling performance of the cathode and is more suitable for dusty environments.

 

Specifications:

Filament Voltage……7.5V

Filament Current (at 7V)……51.5A

Transconductance……11mA/V

Amplification Factor……22

Interelectrode Capacitances (Grounded-cathode)

Input……35pF          Transfer……0.9pF    Output……20Pf

Installation method……Vertical, anode up or down

Cooling……forced air

Diameter……105.56mm

Weight……2.8kg

Temperature at anode shell and sealing joint……250℃

 

Extreme conditions

(Audio power amplifier or class AB or class B modulator)

Anode Voltage……6kV dc

Anode Current……2.5A dc

Grid Voltage……-1000Vdc

Anode Dissipation……4kW

Grid Dissipation……150W

 

Typical conditions (dual tubes, unless specified otherwise, sine wave)

Anode Voltage	4000	5000	6000Vdc
Grid Voltage	-150	-190	-240Vdc
Zero Signal Anode Current	0.6	0.5	0.4Adc
Signal Anode Current	4.0	3.2	3.0Adc
Anode Load	2200	3600	4650Ω
Audio Grid Input (single)	340	360	390V
signal peak excitation	340	230	225W
Signal Nominal Excitation	170	115	113W
Signal Anode Output	11	11	23kW

 

Extreme conditions

(Anode Modulated RF Amplifier Class C, Telephone Talking State)

Anode Voltage……5500V dc

Anode Current……2.0A dc

Grid Voltage……-1000Vdc

Anode Dissipation……2670W

Grid Dissipation……150W

 

Typical conditions (＜30MHz)

Anode Voltage	4000	4500	5000Vdc
Anode Current	1.67	1.47	1.25Adc
Grid Voltage	-450	-500	-550Vdc
Grid Current	180	140	150mAdc
Peak RF Grid Input	685	715	760
Excitation Power	125	100	115 W
Grid Dissipation	43	30	32 W
Anode Input	6670	6615	6250 W
Anode Dissipation	1670	1315	950 W
Anode Output	5000	5300	5300 W

 

Extreme conditions (RF power amplifier or modulator)

Anode Voltage……6000Vdc

Anode Current……2.5Adc

Grid Voltage……-1000Vdc

Grid Current……0.4Adc

Grid Dissipation……150W

Anode Dissipation……4000W

 

Typical conditions (＜30MHz)

Anode Voltage	4000	4500	5000Vdc
Anode Current	2.5	2.5	2.08Adc
Grid Voltage	-300	-450	-500Vdc
Grid Current	245	265	180mAdc
Peak RF Grid Input	580	750	765
Excitation Power	142	197	136W
Grid Dissipation	68	78	46W
Anode Input	10	12.5	12.5kW
Anode Output	7.5	10	10kW
Anode Dissipation	2.5	2.5	2.5kW