4CX250B-M [CPI]

RADIAL BEAM POWER TETRODE; RADIAL束功率四极管
4CX250B-M
型号: 4CX250B-M
厂家: COMMUNICATIONS & POWER INDUSTRIES, INC.    COMMUNICATIONS & POWER INDUSTRIES, INC.
描述:

RADIAL BEAM POWER TETRODE
RADIAL束功率四极管

文件: 总7页 (文件大小:875K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
ChARACTERISTICS1  
ELECTRICAL  
Cathode: Oxide coated, Unipotential  
The Eimac 4CX250B/M is a ceramic/metal,  
forced-air cooled external-anode tetrode with a  
maximum anode dissipation rating of 250 Watts.  
The 4CX250B/M is intended for use in applica-  
tions where tight control of electrical specifica-  
tions is required and replaces the 4CX250B in  
all applications. This tube utilizes a ruggedized  
internal structure and utilizes a welded anode cap  
for improved reliability.  
Filament Voltage  
6.0 0.3  
2.6  
V
A
Current at 6.0 Volts  
Direct Interelectrode Capacitances (grounded cathode)2  
Cin  
Cout  
Cgp  
15.7 pF  
4.5 pF  
0.04 pF  
5
Amplification Factor, Average (screen-grid)  
Frequency of Maximum Ratings (CW)  
500 MHz  
MECHANICAL:  
Overall Dimensions:  
Length  
Diameter  
2.46 in; 62.5 mm  
1.64 in; 41.7 mm  
4 oz; 113 gm  
Any  
Weight (approx.)  
Operating Postition  
Maximum Operating Temperature:  
Ceramic/Metal Seals & Envelope  
Anode Core  
250° C  
250° C  
Cooling  
Forced Air  
Base  
Special, 9-pin Jedec-B8-236  
Recommended Air System Socket  
Recommended Air Chimney  
SK-600 Series  
SK-606  
1 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.  
2 Capacitance values are for a cold tube as measured in a special shielded fixture in accordance with Electronic Industries Association Standard RS-191.  
RANGE VALUES FOR EQUIPMENT DESIGN  
Min.  
Nom.  
Max.  
Filament Current @ 6.0 Volts  
Catꢀode Warm-up Time  
2.3  
30  
--  
60  
2.9  
--  
Amperes  
Seconds  
Interelectrode Capacitance 1 (grounded catꢀode circuit)  
Cin  
14.2  
4.0  
--  
--  
--  
--  
17.2  
5.0  
0.06  
pF  
pF  
pF  
Cout  
Cgp  
Interelectrode Capacitance 1 (grounded grid circuit)  
Cin  
--  
4.0  
--  
13.0  
--  
0.01  
--  
5.0  
--  
pF  
pF  
pF  
Cout  
Cpk  
1 Capacitance values are for a cold tube as measured in a sꢀielded fixture in accordance witꢀ Electronic Industries Assocation Standard RS-191.  
The values listed above represent specified limits for the product and are subject to change. The data should be used for basic  
information only. Formal, controlled specifications may be obtained from CPI for use in equipment design.  
For information on this and other CPI products, visit our website at: www.cpii.com,  
or contact: CPI MPP, Eimac Operation, 607 Hansen Way, Palo Alto, CA 94303  
telephone: 1(800) 414-8823. fax: (650) 592-9988 | email: powergrid@cpii.com  
July 2011  
1
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
RADIO FREQUENCY AMPLIFIER  
Class C, CW Operation  
TYPICAL OPERATION  
Measured Values, Grid-Driven  
ANODE VOLTAGE  
SCREEN VOLTAGE  
GRID VOLTAGE  
500  
250  
-90  
250  
45  
1000  
250  
-90  
250  
38  
1500 2000 Vdc  
ABSOLUTE MAXIMUM RATINGS:  
250  
-90  
250  
21  
250 Vdc  
-90 Vdc  
ANODE VOLTAGE  
2000 Vdc  
300 Vdc  
ANODE CURRENT  
SCREEN CURRENT  
GRID CURRENT1  
DRIVING POWER2  
USEFUL OUTPUT3,4  
1 Approximate Values  
250 mAdc  
19 mAdc  
26 mAdc  
2.9 Watts  
390 Watts  
SCREEN VOLTAGE  
ANODE CURRENT  
0.250 Adc  
250 Watts  
12 Watts  
35  
31  
28  
PLATE DISSIPATION  
SCREEN DISSIPATION  
GRID DISSIPATION  
HEATER-TO-GRID VOLTAGE  
4.0  
70  
3.5  
3.2  
280  
190  
2
Watts  
150 Volts  
2 Approximate, measured in VHF service  
3 Approximate, delivered to the load  
4 For measured case; may vary from tube to tube  
NOTE: TYPICAL OPERATION data are obtained from direct measurement or by calculation from published characteristic curves. Adjustment  
of the rf grid voltage (feedback) 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.  
APPLICATION  
MEChANICAL  
MOUNTING - The 4CX250B/M may be mounted in any position.  
SEA LEVEL  
10,000 FEET  
Anode  
Dissipation Air Flow Pressure  
SOCKETING - The Eimac SK-600 series air system sockets or a  
socket having equivalent characteristics is required. Sockets are  
available with or without built-in screen capacitors and may be  
obtained with either grounded or ungrounded cathode terminals.  
Air Flow  
(CFM)  
Pressure  
Drop  
(In. of Water)  
(Watts)  
(CFM)  
Drop  
(In. of Water)  
200  
250  
5.0  
6.4  
0.52  
0.82  
7.3  
9.3  
0.76  
1.20  
COOLING – Sufficient forced-air cooling must be provided for  
the anode, base seals, and body seals to maintain operating tem-  
peratures below the rated maximum values. Air requirements to  
maintain anode core temperatures at 200°C with an inlet air tem-  
perature of 50°C are tabulated below. These requirements apply  
when a socket of the Eimac SK-600 series and an Eimac SK-606  
chimney are used with an air flow in the base-to-anode direction.  
Tube life is prolonged if the anode temperature is maintained at  
values lower than the maximum rating.  
At 500 MHz or below base cooling air requirements are satisfied  
automatically when the tube is used in an EIMAC Air-System  
socket and the recommended air flow rates are used. Experience  
has shown that if reliable long life operation is to be obtained, the  
cooling air flow must be maintained during standby periods when  
only the heater voltage is applied to the tube. The anode cooler  
should be inspected periodically and cleaned when necessary to  
remove any dirt which might interfere with effective cooling.  
The blower selected in a given application must be capable of  
supplying the desired airflow at a back pressure equal to the  
pressure drop shown in the chart plus any drop encountered in  
ducts and filters. The blower must be designed to deliver neces-  
sary airflow at the desired altitude.  
VIBRATION – The 4CX250B/M is capable of withstanding shock  
and vibration, such as encountered in shipment and normal han-  
dling. The tubes will function well in environments where shock  
and vibration are anticipated.  
2
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
indicated by grid-current values below approx. 15 mA. The  
maximum permissible grid-circuit resistance per tube is 100K  
Ohms.  
ELECTRICAL  
HEATER OPERATION - The rated heater voltage for the  
4CX250B/M, 6.0 volts as measured at the socket, should be  
maintained at this value to obtain optimum performance and  
maximum tube life. In no case should the voltage be allowed to  
deviate from 6.0 volts by more than plus or minus five percent  
(5%). Short-time changes of +/- 10% will not damage the tube,  
but variations in performance must be expected. The heater  
voltage must be maintained within +/- 5% to minimize these  
variations and to obtain maximum tube life.  
SCREEN OPERATION - The maximum rated dissipation for  
the screen grid is 12 Watts and the screen input power must  
be kept below that level. The product of peak screen current  
and peak screen voltage approximates the screen input power  
when amplitude modulation is used. In some cases screen cur-  
rent may tend to be negative. The 4CX250B/M shows reduced  
screen current, compared to the 4CX250B, and is therefore  
preferred for use in amplifiers where screen supply voltage  
regulation is poor or where an increase in screen current above  
the normal value will cause a significant reduction in voltage.  
At UHF increased output (cavity) loading is recommended to  
reduce screen current even if the overall tube efficiency is re-  
duced somewhat.  
At frequencies above approx. 300 MHz transit-time effects be-  
gin to influence the cathode temperature. The amount of driving  
power diverted to heating the cathode by back-bombardment  
will depend upon frequency, anode current, and driving power.  
When the tube is driven to maximum input as a class-C ampli-  
fier, the heater voltage should be reduced according to the table  
below:  
FAULT PROTECTION - All power tubes operate at voltages  
which can cause severe damage in the event of an internal arc,  
especially in those cases where large amounts of stored en-  
ergy or follow-on current are involved. Some means of protec-  
tion is advised in all cases, and it is recommended 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 4CX250B/M a maximum of 4 joules total energy  
may be permitted to be dumped into an internal arc. Amounts  
in excess of this may permanently damage the cathode or the  
tube grids. Additional information is found Eimac’s Application  
Bulletin #17 titled “FAULT PROTECTION,” available on request.  
Frequency Mhz  
300 and lower  
301 to 400  
heater Voltage  
6.00 Volts  
5.76 Volts  
401 to 500  
5.50 Volts  
CATHODE OPERATION - The oxide coated unipotential cathode  
must be protected against excessively high emission currents.  
The maximum rated dc input current is 200 mA for plate modu-  
lated operation and 250 mA for all other types of operation with  
the exception of pulsed applications.  
RF RADIATION - Avoid exposure to strong rf fields even at rela-  
tively low frequency. Absorption of rf energy by human tissue  
is dependent on frequency. Under 300 MHz most of the en-  
ergy will pass completely through the human body with little  
attenuation or heating affect. Public health agencies are con-  
cerned with hazard even at these frequencies. OSHA (Occu-  
pational Safety and Health Administration) recommends that  
prolonged exposure to rf radiation should be limited to 10 mil-  
liwatts per square centimeter.  
The cathode is connected internally to four pins and all four  
should be used to make connection to external circuits to low-  
er inductance. At radio frequencies it is important to keep the  
cathode leads short and direct and to use conductors with large  
areas to minimize the inductive reactances in series with the  
cathode leads.  
It is recommended that the rated nominal heater voltage be ap-  
plied for a minimum of 30 seconds before other operating volt-  
ages are applied. Where the circuit design requires the cathode  
and heater to be operated at different potentials, the rated  
maximum heater-to-cathode voltage of 150 voltage should be  
observed, regardless of polarity.  
INTERELECTRODE CAPACITANCE - The actual internal inter-  
electrode capacitance of a tube is influenced by many variables  
in most applications, such as stray capacitance to the chassis,  
capacitance added by the socket used, stray capacitance be-  
tween tube terminals, and wiring effects. To control the actual  
capacitance values within the tube, as the key component  
involved, the industry and the Military Services use a standard  
test procedure as described in Electronic Industries Associa-  
tion Standard RS-191. This requires the use of specially con-  
structed 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. Other fac-  
tors being equal, controlling internal tube capacitance in this  
way normally assures good interchangeability of tubes over a  
GRID OPERATION - The maximum rated dc grid bias voltage is  
-250 volts and the maximum grid dissipation rating is 2.0 Watts.  
In ordinary audio and rf amplifiers the grid dissipation usually  
will not approach the maximum rating. At operating frequen-  
cies above the 100 MHz region, driving power requirements for  
amplifiers increase noticeably. At 500 MHz as much as 20 Watts  
of driving power may have to be supplied. However, most of the  
driving power is absorbed in circuit losses other than grid dis-  
sipation, so that grid dissipation is only increased slightly. Sat-  
isfactory 500 MHz operation of the tube in a stable amplifier is  
3
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
period of time, even when the tube may be made by different  
manu-facturers. The capacitance values shown in the manu-  
facturer’s technical data, or test specifications, normally are  
taken in accordance with Standard RS-191.  
HIGH VOLTAGE - The 4CX250B/M operates at voltages 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 volt-  
ages. All equipment must include safety enclosures for high-  
voltage circuits and terminals, with interlock switches to open  
the primary circuits of the power supplies and to discharge  
high-voltage condensers whenever access doors are opened.  
Interlock switches must not be bypassed or “cheated” to allow  
operation with access doors open. Always remember that HIGH  
VOLTAGE CAN KILL.  
The equipment designer is therefore cautioned to make allow-  
ance for the actual capacitance values which will exist in any  
normal application. Measurements should be taken with the  
socket and mounting which represent approximate final layout  
if capacitance values are highly significant in the design.  
HOT SURFACES - Air-cooled surfaces and other parts of tubes  
can reach temperatures of several hundred degrees 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,  
Palo Alto, Calif. 94304 for information and recommendations.  
OPERATING HAZARDS  
Proper use and safe operating practices with respect to power tubes are the responsibility of equipment manufacturers and users  
of such tubes. All persons who work with and are exposed to power tubes, or equipment that utilizes such tubes, must take precau-  
tions 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 pre-  
cautions, could result in serious harm to personnel.  
HIGH VOLTAGE – Normal operating voltages can be deadly.  
Remember the HIGH VOLTAGE CAN KILL.  
HOT SURFACES – Surfaces of tubes can reach temperatures  
of several hundred °C and cause serious burns if touched for  
several minutes after all power is removed.  
LOW-VOLTAGE HIGH-CURRENT CIRCUITS - Personal 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.  
MATERIAL COMPLIANCE - This product and package conforms  
to the conditions and limitations specified in 49CFR 173.424 for  
radioactive material, excepted package-instruments or articles,  
UN2910. In addition, this product and package contains no  
beryllium oxide (BeO).  
RF RADIATION – Exposure to strong rf fields should be avoided,  
even at relatively low frequencies. CARDIAC PACEMAKERS  
MAY BE AFFECTED.  
Please review the detailed Operating Hazards sheet enclosed  
with each tube, or request a copy from CPI MPP, Eimac Opera-  
tion Application Engineering at 1-650-592-1221.  
4
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
5
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
6
RADIAL BEAM POWER TETRODE  
4CX250B/M  
7203A  
CPI 072011  
7

相关型号:

4CX250BC

RF amplifier up to 175 MHz
CPI

4CX250FG

RF amplifier up to 175 MHz
CPI

4CX250R

RF linear Amplifier
CPI

4CX3000A

RF amplifier at 30 MHz
CPI

4CX300A

RF Amplifier
CPI

4CX300Y

RF amplifier
CPI

4CX300Y-8561

Plate Dissipation (Max.) 400 Watts Screen Dissipation (Max.) 8 Watts Grid Dissipation (Max.) 1 Watt
ETC

4CX300Y8561

Plate Dissipation (Max.) 400 Watts Screen Dissipation (Max.) 8 Watts Grid Dissipation (Max.) 1 Watt
ETC

4CX35-000C

RF amplifier
CPI

4CX3500A

Grid driven RF amplifier
CPI

4CX350A

RF linear amplifier
CPI

4CX350AC

RF linear amplifier
CPI