艾麦克3CX1500A7 8877高功率三极管说明书-USB迷|专注于互联网分享

2024年7月20日发(作者：赵光辉)

The Eimac 3CX1500A7/8877 is a rugged ceramic

and metal power triode designed for use as a

cathode driven Class AB2 or Class B amplifier in

audio or rf applications including the VHF band,

or as a cathode driven anode modulated Class

C rf amplifier. As a linear amplifier, high power

gain may be obtained with excellent intermodu-

lation distortion characteristics.

Low grid interception and high amplification fac-

tor combine to make the 3CX1500A7/8877 drive

power requirements exceptionally low for a tube

of this power capacity.

CHARACTERISTICS

Cathode: Oxide Coated, Unipotential

Heater Voltage .........................5.0 ± 0.25 V

Heater Current at 5.0 Volts ...............10.5 A

Minimum Warm-up Time ..................3 Min.

Transconductance (Average):

= 1.0 Adc ............................55,000 µmhos

Amplification Factor

(Average)

.................. 200

Direct Interelectrode Capacitances

(

grounded grid)

Cin ....................................................38.5 pF

Cout ..................................................10.0 pF

Cpk .....................................................0.1 pF

Ck-htr .................................................9.7 pF

Direct Interelectrode Capacitances

(

grounded cathode)

Cin ....................................................38.5 pF

Cout ...................................................0.1 pF

Cgp ..................................................10.0 pF

Frequency of Maximum Ratings ........ 250 MHz

Overall Dimensions:

Height ...........................4.02 in: 102.16 mm

Diameter .........................3.83 in; 85.85 mm

Net Weight ..............................25 oz; 708.8 gm

Operating Position ......................................Any

Maximum Operating Temperature:

Ceramic/Metal Seals & Anode Core.. ....

250° C

Cooling .............................................Forced Air

Base .............................................Special, 7-pin

Recommended Air System Socket:

Grounded Grid ...............................SK-2210

Grounded Cathode ........................SK-2200

Recommended Air Chimney (teflon)

.........SK-2216

Characteristics and operating values are based upon performance tests. These figures may change without notice as the result of additional data or product

refinement. CPI MPP Eimac Operation should be consulted before using this information for final equipment design.

Capacitance values are for a cold tube as measured in a special shielded fixture in accordance with Electronic Industries Association Standard RS-191.

/mpp

May 2020

RANGE VALUES FOR EQUIPMENT DESIGN

Min. Max.

9.5

36.0

9.2

---

11.5

---

41.0

11.2

0.2

Amperes

Minutes

Heater:****************

Cathode Warm-up Time

Interelectrode Capacitances

(grounded grid circui)

Cin

Cout

Cpk

Capacitance values are for a cold tube as measured in a shielded fixture in accordance with Electronic Industries Assocation

Standard RS-191.

RADIO FREQUENCY LINEAR AMPLIFIER

CATHODE DRIVEN Class AB

ABSOLUTE MAXIMUM RATINGS:

DC 4000 V

DC ANODE CURRENT ................... 1.0 A

ANODE DISSIPATION .................1500 W

GRID DISSIPATION ....................... 20 W

CATHODE-TO-HEATER VOLTAGE

...250 Vdc

TYPICAL OPERATION - Frequencies to 30 MHz

Peak Envelope or Modulation Crest Conditions

ANODE VOLTAGE .................................... 2700

CATHODE VOLTAGE

............................... +8.2

ZERO-SIGNAL ANODE CURRENT

................ 92

SINGLE-TONE 740

TWO-TONE 480

SINGLE-TONE GRID CURRENT

................... 40

TWO-TONE GRID CURRENT

...................... 16

Positive cathode bias provided by zener diode.

The intermodulation distortion products are referenced

against one tone of a two-equal-tone signal.

Approximate values.

3500

+8.2

182

1000

675

Vdc

mAdc

PEAK RF CATHODE VOLTAGE

..................... 68

DRIVING IMPEDANCE ................................. 58

PEAK DRIVING POWER

.............................. 40 64

SINGLE-TONE USEFUL OUTPUT POWER

... 1085 2075

RESONANT LOAD IMPEDANCE .............. 1820 2000

INTERMODULATION DISTORTION

3rd ORDER PRODUCTS ............................ -40 -38 dB

5th ORDER PRODUCTS ............................ -41 -41dB

RADIO FREQUENCY LINEAR AMPLIFIER

CATHODE DRIVEN Class AB

ABSOLUTE MAXIMUM RATINGS:

DC 4000 V

DC ANODE CURRENT ................... 1.0 A

ANODE DISSIPATION .................1500 W

GRID DISSIPATION ....................... 20 W

CATHODE-TO-HEATER VOLTAGE

...250 Vdc

TYPICAL OPERATION (200 MHz)

2500 Vdc

CATHODE VOLTAGE

...................... +8.2 Vdc

ANODE CURRENT ...........................1000 mAdc

GRID CURRENT

.................................. 10 mAdc

USEFUL OUTPUT POWER

.............. 1520 W

DRIVING POWER

........................... 57 W

POWER GAIN

...................................... 14 dB

Positive cathode bias provided by zener diode.

Approximate values.

3CX1500A7/8877

RADIO FREQUENCY POWER AMPLIFIER

Class B Telegraphy or FM

(Continuous Operating Conditions)

ABSOLUTE MAXIMUM RATINGS:

DC 4000 V

DC ANODE CURRENT ................... 1.0 A

ANODE DISSIPATION .................1500 W

GRID DISSIPATION ....................... 20 W

CATHODE-TO-HEATER VOLTAGE

...250 Vdc

For measured case, idling anode current was set for 10 mAdc.

Approximate values.

Approximate, delivered to the load.

For the measured case, may vary from tube to tube.

TYPICAL OPERATION - 88 - 108 MHz)

Measured Values Class B, Cathode Driven

ANODE VOLTAGE ........................ 2000

CATHODE VOLTAGE

1,2

.................... +9

.1.0

GRID CURRENT

................................ 60

2500 3000 4000Vdc

+12

1.0

+15 +20Vdc

1.0 1.0

42 25

65 78

Adc

mAdc

DRIVING POWER

............................ 64 54

USEFUL OUTPUT POWER

............ 1330 1670 19602600

EFFICIENCY

................................... 66.7 66.7 66.5 65.2

POWER GAIN

................................ 13.2 14.2 14.8 15.3

RADIO FREQUENCY POWER AMPLIFIER

Class C, Cathode Driven

Plate Modulated

ABSOLUTE MAXIMUM RATINGS:

DC 3200 V

DC ANODE CURRENT ................... 0.8 A

ANODE DISSIPATION .................1000 W

GRID DISSIPATION ....................... 20 W

CATHODE-TO-HEATER VOLTAGE

...250 Vdc

Bias may be obtained from a fixed supply of 15.8 volts

in series with a 9.5 ohm resistor. The resistor and supply

Approximate.

Approximate, and driver must be modulated approximately 83%.

TYPICAL OPERATION (Frequencies to 30 MHz

Carrier Conditions)

2400 Vdc

CATHODE VOLTAGE

...................... +22 Vdc

ANODE CURRENT ........................... 600 mAdc

GRID CURRENT

.................................. 45 mAdc

ANODE LOAD RESISTANCE .......... 2000 Ω

DRIVING POWER

........................... 41 W

ANODE OUTPUT POWER ................1000 W

14 dB

TYPICAL OPERATION

NOTE: TYPICAL OPERATION data are obtained from direct measurement or by calculation from published characteristic

curves. Adjustment of the rf grid voltage to obtain the specified anode current at the specified bias and anode voltages

is assumed. If this procedure is followed, there will be little variation in output power when the tube is changed, even

though there may be some variation in grid current. The grid current which results when the desired anode current is ob-

tained is incidental and varies from tube to tube. These current variations cause no difficulty so long as the circuit main-

tains the correct voltage in the presence of the variations in current. If grid bias is obtained principally by means of a grid

resistor, the resistor must be adjustable to obtain the required bias voltage when the correct rf grid voltage is applied.

MECHANICAL

MOUNTING – The 3CX1500A7/8877 may be mounted in

any position.

SOCKETING - The grid of the 3CX1500A7/8877 terminates in

the cylindrical grid ring about the base of the tube. This may

be contacted by multiple clips or flexible finger stock. Connec-

tions to the heater and cathode are made via the 7-pin base.

The Eimac SK-2210 socket is recommended for all rf amplifier

applications.

STORAGE – If a tube is to be stored as a spare it should be

kept in its original shipping carton, with the original packing

material, to minimize the possibility of handling damage. Be-

fore storage a new tube should be operated in the equipment

for 100 to 200 hours to establish that it has not been damaged

and operates properly. If the tube is still in storage 6 months

later it should be operated in the equipment for 100 to 200

hours to make sure there has been no degradation. If opera-

tion is satisfactory the tube can again be stored with great as-

surance of being a known-good spare.

COOLING - The maximum temperature limit for external tube

surfaces and the anode core is 250°C. Tube life is prolonged

if these areas are maintained at lower temperatures. For full

1500 watts anode dissipation 35.0 cfm of air is required at

a back pressure of 0.41” H

O hold tube temperature below

225°C with 50°C ambient temperature at sea level. At frequen-

cies higher than 30 MHz, or at high altitudes, the air quantity

must be increased. The data shown is based on airflow in the

base-to-anode direction.

SEALEVEL

10,000

FEET

Dissipation

AnodeAir PressurePressure

(Watts)(CFM)

Flow

(In. of Water)

Drop

(CFM)

Flow

Air

(In. of Water)

Drop

500 7.50.1011.00.15

100022.50.2032.50.29

150035.00.4151.00.60

NOTES:

1. Tube mounted in SK-2200 Socket with SK-2216 Chimney.

2. An allowance of 25 watts has been made for grid dissipation

and 50 watts for filament power.

ELECTRICAL

ABSOLUTE MAXIMUM RATINGS - Values shown for each

type of service are based on the “absolute system” and are

not to be exceeded under any service conditions. These rat-

ings are limiting values outside which serviceability of the tube

may be impaired. In order not to exceed absolute ratings the

equipment designer has the responsibility of determining an

3CX1500A7/8877

average design value for each rating below the absolute

value of that rating by a safety factor so that the absolute

values will never be exceeded under any usual conditions

of supply-voltage variation, load variation, or manufactur-

ing variation in the equipment itself. It does not necessarily

follow that combinations of absolute maximum ratings can

be attained simultaneously.

HEATER OPERATION – The heater power supply should

be isolated from ground (ie.; no center tap on the sec-

ondary of a transformer if used). The rated heater voltage

for the 3CX1500A7/8877 of 5.0 volts, as measured at the

socket, should be maintained at this value to obtain op-

timum performance and maximum tube life. In no case

should the voltage be allowed to deviate from 5.0 volts

by more than plus or minus five percent (5%). This tube

is designed for normal commercial service, where one

heater on/off cycle is anticipated per day. Contact Eimac

Application Engineering if more daily on/off cycles are ex-

pected.

CATHODE WARM-UP/COOL-DOWN TIME - It is recom-

mended that heater voltage be applied for a minimum of

three minutes before anode voltage and drive voltage are

applied, to allow for proper conditioning of the cathode

surface. It is also recommended that after all voltages are

removed from the tube that air cooling be allowed to run

for several minutes to allow for proper cooldown.

INPUT CIRCUIT - When the 3CX1500A7/8877 is operated

as a cathode driven rf amplifier, the use of a resonant cir-

cuit in the cathode is recommended. For best results

with a single ended amplifier, it is suggested that the

cathode tank circuit operate with a “Q” of 5 or more.

ZERO-BIAS OPERATION - Operation at zero-bias is not

recommended with anode potentials over 3000 volts,

since anode dissipation may be exceeded. Higher anode

voltage may be used with proper protective bias.

FAULT PROTECTION - All power tubes operate at volt-

ages which can cause severe damage in the event of an

internal arc, especially in those cases where large amounts

of stored energy or follow-on current are involved. Some

means of protection is advised in all cases, and it is rec-

ommended that a series resistor be used in the anode

circuit (20 to 50 ohms) to limit peak current and provide

a means of dissipating the energy in the event of a tube

or circuit arc. For an oxide-cathode tube such as the

3CX1500A7/8877, a maximum of 4 joules total energy

should be permitted to be dumped into an internal arc.

Amounts in excess of this may permanently damage the

cathode or the grid structure. Additional information is

found Eimac’s Application Bulletin #17 titled “FAULT PRO-

TECTION,” available on request.

RF RADIATION - Avoid exposure to strong rf fields even at

relatively low frequency. Absorption of rf energy by human

tissue is dependent on frequency. Under 300 MHz most of

the energy will pass completely through the human body with

little attenuation or heating affect. Public health agencies are

concerned with the hazard, and the published OSHA (Occu-

pational Safety and Health Administration) or other local rec-

ommendations to limit prolonged exposure of rf radiation

should be followed. It is worth noting that some commer-

cial dielectric heating units actually operate at frequencies as

low as the 13 and 27 MHz bands.

INTERELECTRODE CAPACITANCE - The actual internal inter-

electrode capacitance of a tube is influenced by many vari-

ables in most applications, such as stray capacitance to the

chassis, capacitance added by the socket used, stray capaci-

tance between tube terminals, and wiring effects. To control

the actual capacitance values within the tube, as the key com-

ponent involved, the industry and the Military Services use a

standard test procedure as described in Electronic Industries

Association Standard RS-191. This requires the use of special-

ly constructed test fixtures, which effectively shield all external

tube leads from each other and eliminates any capacitance

reading to ‘ground’. The test is performed on a cold tube in

a special shielded fixture.

Other factors being equal, controlling internal tube ca-

pacitance in this way normally assures good interchange-

ability of tubes over a period of time, even when the tube

may be made by different manufacturers. The capacitance

values shown in the manufacturer’s technical data, or test

specifications, normally are taken in accordance with Standard

RS-191. The equipment designer is therefore cautioned to

make allowance for the actual capacitance values which will

exist in any normal application. Measurements should be

3CX1500A7/8877

taken with mounting which represents approximate final

layout if capacitance values are highly significant in the

design.

Many Eimac power tubes such as this are specifically de-

signed to generate or amplify radio frequency power.

There may be a relatively strong rf field in the general

proximity of the power and its associated circuitry - the

more power involved the stronger the rf field. Proper en-

closure design and efficient coupling of rf energy to the

load will minimize the rf field in the vicinity of the power

amplifier itself.

HIGH VOLTAGE - The 3CX1500A7/8877 operates at volt-

ages which can be deadly, and the equipment must be

designed properly and operating precautions must be

followed. Equipment must be designed so that no one

can come in contact with high voltages. All equipment

must include safety enclosures for high-voltage circuits

and terminals, with interlock switches to open the prima-

ry circuits of the power supplies and to discharge high-

voltage capacitors whenever access doors are opened.

Interlock switches must not be bypassed or “cheated” to

allow operation with access doors open. Always remem-

ber that HIGH VOLTAGE CAN KILL.

HOT SURFACES - Air-cooled surfaces and other parts

of tubes can reach temperatures of several hundred de-

grees C and cause serious burns if touched for several

minutes after all power is removed.

SPECIAL APPLICATIONS - If it is desired to operate this

tube under conditions widely different from those given

here, contact the Application Engineering Dept., CPI

MPP Eimac Operation for information and recommenda-

tions.

3CX1500A7/8877

OPERATING HAZARDS

Proper use and safe operating practices with respect to power tubes are the responsibility of equipment manu-

facturers and users of such tubes. All persons who work with and are exposed to power tubes, or equipment

that utilizes such tubes, must take precautions to protect themselves against possible serious bodily injury.

DO NOT BE CARELESS AROUND SUCH PRODUCTS.

The operation of this tube may involve the following hazards, any one of which, in the absence of safe operating

practices and precautions, could result in serious harm to personnel.

Please review the detailed Operating Hazards Sheet enclosed with each tube, or request a copy from CPI Micro-

wave Power Products, Eimac Operation.

HIGH VOLTAGE – Normal operating voltages can be

deadly. Remember the HIGH VOLTAGE CAN KILL.

LOW-VOLTAGE HIGH-CURRENT CIRCUITS - Per-

sonal jewelry, such as rings, should not be worn

when working with filament contacts or connectors

as a short circuit can produce very high current and

melting, resulting in severe burns.

RF RADIATION – Exposure to strong rf fields should

be avoided, even at relatively low frequencies.

CARDIAC PACEMAKERS MAY BE AFFECTED.

HOT WATER – Water used to cool tubes may

reach scalding temperatures. Touching or rupture

of the cooling system can cause serious burns.

HOT SURFACES – Surfaces of tubes can reach

temperatures of several hundred°C and cause se-

rious burns if touched for several minutes after all

power is removed.

MATERIALS COMPLIANCE - This product and

package conforms to the conditions and limita-

tions specified in 49CFR 173.424 for radioactive

material, excepted package-instruments or ar-

ticles, UN2910. In addition, this product and pack-

age contains no beryllium oxide (BeO).

3CX1500A7/8877

Microwave Power

Products Division

tel: +1 650-846-2800

email: *********************

web: /mpp

For more detailed information, please refer to the corresponding CPI

technical description if one has been published, or contact CPI. Specifications

may change without notice as a result of additional data or product refinement.

Please contact CPI before using this information for system design.

reproduction is strictly prohibited without written authorization from CPI.