Instruction Manual - BCDX C

1 Svetlana Outline drawingCharacteristicsTSVETLANA technical DATAM arketing & Engineering: DEVICESS vetlana8200 South Memorial ParkwayHuntsville, AL 35802 USAP hone:205 882 1344 Fax:205 880 80773000 Alpine RoadPortola Valley, CA 94028 USAP hone:415 233 0429 Fax:415 233 0439he Svetlana 572b is a high-mu power triode intended for use in class AB, class Band class C RF and Audio amplifiers. The Svetlana 572b features a massive graphiteanode for high peak overload capability and a high average plate dissipation of 160 Watts. The Svetlana 572b also features a low loss ceramic base and a bonded-ceramic plate cap thermal insulator for high power RF transmitting tube capability. The Svetlana 572b has a superior getter system based on titanium adhered to the externalsurface of the graphite anode. The titanium coating covers the entire anode area extended bythe inherent micro surface roughness of graphite.

2 The Svetlana 572b envelope is fabricatedfrom hard glass intended specifically for the high-temperature operation of transmitting tubes. The internal tube parts are supported by low loss ceramic insulators for high-temperatureoperation and high voltage hold-off. The internal structure is well supported and is aligned withrespect to the base pins to avoid internal shorts in equipment designed for horizontal tubemounting. The Svetlana 572b may be used as a direct drop-in replacement in equipment designed forthe 811A, T160L or :Thoriated-tungsten Voltage (AC or DC) V Current4 AAmplification factor (average)170 Direct interelectrode capacitances: Grid to Grid to pF Plate to pFMaximum frequency for full ratings30 MHzMechanicalCoolingRadiation and forced airBaseCeramic, standard small four pinPlate capStandard medium cap 14 mm dia. with ceramic thermal insulationPlate connectorSvetlana PC-1A or equivalentSocketSvetlana SK4A, Standard small, four contactOperating position-Axis vertical, base down or horizontal w/ pins 1 and 4 in vertical planeNominal dimensions: mm ( in.)

3 Base to plate mm ( in.) Overall mm ( in.)Net weight113 gmLinear RF Power Amplifier, Class B Grounded Grid, Maximum ratings ICAS*DC plate voltage2750 VDC plate current275mAPlate dissipation160 WDC Plate input600 WDC Grid current50mA*Intermittant commercial and ameteur service572 BHigh-Mu Power Triode8 mmNCP2314 GFLow lossceramicbase, smallfour pinCeramicthermalinsulationPlate connectionstandard medium cap,14 mm :The internal structure is aligned withrespect to the base pins to avoidinternal shorting problems in equip-ment designed for horizontal pin connections,bottom DEVICESS vetlanaTypical Operation, Grounded Grid Linear Amplifier(frequencies to 30 MHz) ICAS**DC plate voltage2400 VDC grid voltage-2 VZero-signal DC plate current **45mASingle-tone DC plate current250mADriving power50 WSingle-tone useful output power **300W** Approximate valueSvetlana 572 BHigh-Mu Power TriodeEc = 0 PLATE VOLTAGE (VOLTS)CURRENT (MILLIAMPERES)24001600120080002800200040 08006004002000Ef = VoltsPlate CurrentGrid CurrentSvetlana 572 BTypical Performance Curves+10+20+40+60+80+100+120+120+100+80 +60+40+20+10 Versions of the 572b designed for audio amplifier service are for SV572 Series ApplicationMounting.

4 The Svetlana 572b may be operated with its axisvertical and the base down, or horizontally with pins 1 and 4 ina vertical Radio572 BTECHNICAL TOPICSA rticle as first appeared in RadCom Magazine(October 1996)A letter from George Badger, W6TC, of Svetlana notes that theYaesu FL-2100 series of linears, using the 572b high-muhigh-power triode, has proved very popular in the UK. He points outthat the new Svetlana 572b has slightly higher gain than theoriginal. When fitted in the FL-2100, Fl-2100B, FL2100B andFL2100F linears they sometimes oscillate in the standby modebecause, as Yaesu has confirmed, the cut-off bias is only slightlyhigher than cut-off. If the amplifier 'takes off' as an unloaded TPTG oscillator it can wreak bought a used FL-2100B and modified the bias circuit: Fig 5shows the original arrangement and Fig 6 the modification,incorporating a voltage-doubler configuration to increase thestand-by cut-off bias.

5 After modification, the amplifier becomesunconditionally stable when fitted with the higher-gain SvetlanaTechnical Bulletin 15file:///C|/WINDOWS/DESKTOP/Industrial Tubes/ technical Bulletin (1 of 3) [10/7/2002 9:13:55 PM] 5: Stand-by bias arrangement as used in the Yaesu FL-2100B linear : How W6TC modified the stand-by bias in his FL-2100B to increase the bias voltage by using avoltage-doubler arrangement in order to ensure unloaded stability when the higher-gain Svetlana 572 Bvalve is Heathkit SB-200 which uses a similar circuit has 100V cut-off bias and isstable when fitted with the Svetlana 572b . This applies also to the new Svetlana 572b features a massive graphite anode for high peak overloadcapability and an average anode dissipation of 160W. Typically, as a linear Class Bgrounded-grip amplifier with HT and 50W drive, it can provide asingle-tone useful output power of about 300W.

6 It can be used as a drop-inreplacement for the 811A to provide up-graded Bulletin 15file:///C|/WINDOWS/DESKTOP/Industrial Tubes/ technical Bulletin (2 of 3) [10/7/2002 9:13:55 PM]Svetlana Electron Devices, Inc (3000 Alpine Road, Portola Valley, CA 94028,USA) can also supply a 4CX400A tetrode for linear amplifier service and also arelatively inexpensive Svetlana SK2A ceramic socket for this valve. In the AB2mode with EHT, it can produce over 600W PEP with low intermodulationdistortion. A pair can produce PEP or CW at up to 500 MHz.**The information provided in this application note is intended for general design guidance only. The userassumes all responsibility for correct and safe usage of this information. Svetlana Electron Devices doesnot guarantee the usefulness or marketability of products based on this to technical Bulletins ListingTechnical Bulletin 15file:///C|/WINDOWS/DESKTOP/Industrial Tubes/ technical Bulletin (3 of 3) [10/7/2002 9:13:55 PM]