12BV7

Class of medium-low gain, pentode vacuum tube amplifiers GE-12DQ7-tube.jpg General Electric 12BY7A vacuum tube (note equivalency markings) Pentode TV & Radio 2+5/8 7/8 Indirectly Heated (Coated Unipotential) Series / Parallel 12.6 V / 6.3 V Series / Parallel 300 mA / 600 mA 6.5 W 300 V 9BF Pin 1, Cathode Pin 2, Grid 1 Pin-3, Internal Shield / Grid 3 (Suppressor) Pin-4, Heater Pin-5, Heater Pin-6, Heater Center Tap Pin-7, Plate Pin-8, Grid 2 (Screen) Pin-9, Internal Shield / Grid 3 (Suppressor) 28.5 250 V 26 mA 180 V http://www.datasheetarchive.com/12BV7-datasheet.html The 12BV7, 12BY7, 12BY7A, and equivalents were a class of medium-low gain, pentode vacuum tube amplifiers using the Noval socket configuration. Although originally marketed as pentode tubes for use in early television receivers, they found additional uses in audio and radiotelephone equipment. The series shares the EIA 9BF pinout with a number of other miniature pentode tubes of the era. The most successfulApril 2016 tube in this series, 12BY7A was introduced by General Electric in June 195512BY7A @ The National Valve Museum http://www.r-type.org/exhib/aas0006.htm Jan 12, 2015 as a demodulated video signal amplifier for television receivers. Its design specifications called for linear gain along a wide bandwidth (approximately 4 MHz) with low transconductance (13 Millimhos (Millisiemens)) and high sensitivity. This combination of sensitivity, bandwidth and price lead to its popularity in audio amplification systems during the tube era.April 2016 Functional equivalents Like other vacuum tubes of US and Japanese manufacture, the RETMA tube designation system was used to designate identical tubes across different manufacturers. Any variations from the original electrical design specifications required a change to the tube designation code. As a result, a number of cross-reference resources exist.Tube Interchangibility Reference http://www.nostalgickitscentral.com/info/tubexref12.html Nostalgic Kits Central 15 January 2015 In some cases, multiple tube designation numbers were marked on the tube itself.http://www.computerhistory.org/collections/catalog/102730562 Computer History Museum - Vacuum tube type 12BY7A/12BV7 12BY7 12BY7 was an immediate successor to the 12BV7 and provided the same overall amplification values, but had slightly higher screen dissipation and voltage ratings. The tube exhibited slightly lower transconductance ratings (11 mS vs the original specification of 13 mS) as a result of this change.12BV7 - GE Electronic Tubes reference, January 1959 http://www.datasheetarchive.com/dl/Scans-008/Scans-00172731.pdf 23 January 2015 https://web.archive.org/web/20160304054221/http://www.datasheetarchive.com/dl/Scans-008/Scans-00172731.pdf 2016-03-04 dead 12BY7A The most popular variant from the original 12BV7 was the 12BY7A. In this case, the A suffix is used to indicate a backwards-compatible revision to the original specification. Specifically, the heater filament had been redesigned to further protect it from the potentially damaging voltage spikes which were known to occur when the tube heater circuits were wired in series rather than parallel. All of the other design specifications, including warmup time, were identical to the 12BY7. 12DQ7 The 12DQ7 was the final backwards compatible update to the 12BV7. It offered higher maximum screen and plate voltages of 330VAC. The transconductance value was further reduced from 11 mS to 10.5 mS.12DQ7 - GE Electronic Tubes reference, April 1958 http://www.nj7p.org/Tubes/PDFs/Frank/093-GE/12DQ7.pdf General Electric 21 March 2016 7733 The 7733 is listed as a premium version of the 12BY7A variant suitable for industrial or instrument service.http://www.radiomuseum.org/tubes/tube_7733.html 7733, Tube 7733; Röhre 7733 ID6211, Vacuum Pentode EL180 This is the European Mullard–Philips tube designation number for the 12BY7A variant. The code breakdown is as follows: E = Heated Cathode - Heater voltage = 6.3VAC, 6.3VDC Parallel, 12.6VDC Series L = Type of Device = Power tetrode, beam tetrode or power pentode 180 = Noval socket, B9A pinout. Usage outside of television reception High-fidelity audio equipment Although intended for video signal pre-amplification, the relatively high Mu to bandwidth ratio of the 12BY7 and 12BY7A variants lead to their adoption in audio amplification equipment during the Hi-Fi era. There is some dispute in the audio community as to whether the 12DQ7 and 12BV7 variants are acceptable substitutes when discussing the psychoacoustics of various amplifiers.Triode or Pentode http://audiokarma.org/forums/index.php?threads/triode-or-pentode.187717/ AudioKarma.org 21 March 2016 4 June 2016 https://web.archive.org/web/20160604034104/http://audiokarma.org/forums/index.php?threads%2Ftriode-or-pentode.187717%2F dead Harman Kardon Citation II - Utilized six 12BY7As (three per audio channel) as pre-amplifiers driving four KT88 tetrode final stage amplifiers (two per channel) in a push-pull configuration. When driven to 60 Watts, this configuration resulted in approximately 40 kHz of audio frequency bandwidth (18 Hz - 40 kHz) extending into the ultrasonic range.Harman Kardon Citation II http://www.highfidelityreview.com/harman-kardon-citation-ii.html High Fidelity Review 21 March 2016Citation II Operation ManualHarman Kardon Citation II http://www.hifiengine.com/manual_library/harman-kardon/citation-ii.shtml hifiengine.com Radio transceivers The tube series' wide-bandwidth characteristics lead a number of manufacturersKemsi Ken Kenwood Hybrid Transceiver FAQ http://www.k4eaa.com/faq.htm Kenwood Hybrid Transceiver Sales, Restoration & Service 4 September 2015Instruction Manual TR-4 Sideband Transceiver R. L. Drake Company 5 http://bama.edebris.com/manuals/drake/tr4/ 4 September 2015 TR4 to utilize later variants, such as the 12BY7A as a transmit exciter and/or receive preamplifier in the RF stages of their radios. This RF design remained in use throughout the 1970s and early 1980s even as the other stages were replaced with Solid State components. Equipment using mixed tube & solid-state technologies came to be known as "Hybrid" or "Hybrid Solid State". Partial list of amateur radio equipment manufacturers using the 12BV7, 12BY7A or equivalents Gonset Communicator GC-105,Communicator GC-105 https://www.radiomuseum.org/r/gonset_communicator_gc_105gc10.html Radio Museum 1 August 2020 G28Gonset 10-meter Fixed-Station Transceiver http://bama.edebris.com/download/gonset/g28/G-28.pdf Boat Anchor Manual Archive 1 August 2020 Trio (later Kenwood) - TS-520, TS-820, TS-530, TS-830, R-820 R.L. Drake Company - TR4, 2-NTBenson George Classic Radio: The Drake 2-NT Novice Transmitter QST 103 9 78–79 Yaesu Musen (later Yaesu) - FT-101, FT-200 (Also resold as the Henry Tempo One)Tempo One http://foxtango.org/ft250/foxtango%20FT200%20Information%20Page.html Side-Band Engineers - SBE-34SBE-34 Specifications http://www.qsl.net/la5ki/org/sb/sbe34s.htm Hallicrafters - HT-37HT-37 https://www.radiomuseum.org/r/hallicraft_ht_37_ht37.html Electronic Test Equipment The Tektronix 555 Modular Oscilloscope utilized a total of six 12BY7 and 12BY7A tubes. Four 12BY7s were specified for the main chassis as vertical amplifiers for the CRT beams (V1014, V1024, V2014, V2024), and one 12BY7A each in the Type 21 and Type 22 time-base modules (V145)Instruction Manual - Type 555 Oscilloscope Tektronix, Inc. Beaverton, OR, US http://bama.edebris.com/manuals/tek/555/ 9-19,9-33,9-39 References Category:Vacuum tubes