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History of the manufacturer  

B&K (Precision), Dynascan Corp., Cobra Electronics; Chicago, IL and Yorba Linda, CA

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Name: B&K (Precision), Dynascan Corp., Cobra Electronics; Chicago, IL and Yorba Linda, CA    (USA)  
alternative name:
B&K Manufacturing Company
Abbreviation: bk-precisi
Products: Model types

B&K Manufacturing Co.
3726 N. Southport Ave., Chicago 13, Illinois (1960s)

B&K - Products of Dynascan
1801 W. Belle Plaine Ave., Chicago, IL 60613 (1974)

B&K Precision - Products of Dynascan
1801 W. Belle Plaine Ave., Chicago, IL 60613 (1975)

B&K Precision Corporation
22820 Savi Ranch Parkway, Yorba Linda, CA 92887-4610 (2016)

Cobra Electronics Corporation
6500 W. Cortland St, Chicago, IL 60707 (2016)

Due to the complicated history of brands, company names and subdivisions, all models made by B&K, Dynascan and Cobra Electronics are pooled under this manufacturer entry.

Founded: 1948

For more than 50 years B&K Precision has provided test and measurement solutions to customers from wide-ranging fields including research and development, product design, industrial maintenance, electronic field service, production line testing, and the educational community, among others. Universities and technical schools worldwide have made the instruments standard equipment in their training programs.

B&K Precision helped pioneer the electronic testing industry, and like so many early electronics firms, B&K started in a garage. By 1948, when Americans had begun buying televisions in large numbers, Chicago entrepreneur Carl Korn and his partner Philip Ban responded to the need for maintenance of often-unreliable sets. Frustrated by a lack of equipment to easily test television components, Ban and Korn began making their own devices and opened Central Television Service Company. They soon had a thriving business selling CRT rejuvenators and vacuum tube testers to other television service shops. By 1951, Korn had developed what would become B&K Precision into a company that had branched out into other areas of electronic testing and measurement. B&K engineers broke new ground, earning several patents in the field of television test equipment, and rapidly pushing the company to become a worldwide leader in electronic measurement.
In 1961, Carl Korn placed B&K Precision under an umbrella corporation, Dynascan, comprising a variety of electronics firms. One of those companies, Cobra Electronics, came to dominate the Citizen's Band (CB) radio phenomenon. Choosing to focus on radios, Korn sold B&K Precision. Through an ensuing series of ownership transitions B&K continued to produce high-quality testing and measurement products.
In 1996, engineer Victor Tolan, headed up a new ownership team for B&K Precision that launched a greatly expanded product line. The company also expanded upon its American base to better serve international customers. Company headquarters moved to southern California to provide improved service to Asia. In 2004 B&K expanded its presence in Europe through the acquisition of Sefram Instruments to better meet customer needs in the region.

B&K Precision has come a long way from its days in Carl Korn's garage, but holds fast to the business ideals of innovation, flexibility, and solid customer service that have guided us from our humble beginnings in America, while reaching out to embrace the rapidly expanding global marketplace. We now provide service and support on four continents, and our design team draws upon resources in places as wide-ranging as Romania, Israel, and Taiwan.

In 1948, Carl Korn founded Central Television Service Company to provide repair service for the fledgling television industry. The industry expanded so quickly that service equipment soon became outdated. Thus, Carl and his associates began designing, producing and marketing their own test equipment. Soon, B&K Electronics was born.

1950s and 1960s
Throughout the 50s and early 60s, B&K Electronics, along with many other small electronics companies, joined forces to form Dynascan Corporation. In 1963, Dynascan engineers developed the world’s first citizens band (CB) radio, the Sidewinder, which was shortly followed by the Cobra. With widespread acceptance of CBs in the marketplace, the Cobra name caught on with consumers and eventually evolved into the symbol and brand name for this signature product.

The early 80s were boom years, with the introduction of cordless telephones and radar detectors. The Cobra name soon came to stand for technical innovation. By 1987, the company was propelled exclusively into the consumer electronics market.

In 1993, the corporate name was formally changed from Dynascan to Cobra Electronics Corporation with the NASDAQ stock trading symbol of COBR. Cobra Electronics identified the need for unique products and renewed its focus on product innovation and high-impact merchandising. This new strategy began paying impressive dividends in 1997, when the company registered double-digit revenue growth and a five-fold increase in earnings.

In January 1998, James (Jim) R. Bazet  was named president and chief executive officer of Cobra Electronics Corporation. Under Jim’s leadership, the company continued to improve revenue and earnings.

Proving that providing quality products and service does not go unrecognized by customers, Cobra Electronics was the top performer in the CB radio, radar detection and two-way radio categories by the year 2000. Moving into the 21st century, Jim Bazet and the executive team focused on Cobra's global presence. In 2003, in addition to maintaining a leadership role in its core categories, Cobra Electronics entered two new growth categories—marine electronics and mobile navigation.

Cobra Electronics Corporation has grown and prospered over the past 50 years to become a leading designer and marketer of consumer electronics products. Once a small television repair business located in founder Carl Korn’s garage, Cobra Electronics products can now be found in more than 75 countries and 55,000 storefronts globally and continues to grow throughout the world.

Today’s product offerings include a large array of devices for anyone from professional drivers and driving enthusiasts to outdoor recreational and boating enthusiasts

This manufacturer was suggested by Wolfgang Scheida.

Some models:
Country Year Name 1st Tube Notes
USA  74 PAC-24   Dynascan PAC-24 Power Station; 12 VDC, power supply for CB base station operation (Cobra ... 
USA  66 B+K Precision CRT Tester / Rejuvenator 470   Dynascan Picture Tube Tester / Rejuvenator Model B+K Precision 470. 
USA  65 Sweep/Marker Generator 415   B&K Dynascan 415 Sweep/Marker Generator; Universal Tool to align a TV RF and IF Circuit, S... 
USA  65 Television Analyst 1077B   Containes a flying spot scanner to generate test patterns on the tv being serviced. Genera... 
USA  70 Radio Analyst 970   Radio Analyst for Transistor Radios with built-in power supply, audio generator, 250kHz to... 
USA  56 Rejuvenator Tube Tester 400   4.5" meter. TV picture tube tester. 
USA  56 Dyna-Quik Tube Tester 500 6AT6  Dynamic mutual conductance tube tester. Checks RF, IF, AGC, and critical sync tubes direct... 
USA  71 Dyna-Jet Tube Tester B&K 747 2N5458  Gehäuse in Form eines Aktenkoffers mit Tragegriff. Vollständiger Modellname: Dyna-Jet soli... 
USA  65 Dyna-Jet 606 6BN8  B & K - Emission Tube Tester (shorts and quality test) - Provavalvole ad emissione (contro... 
USA  75 Solid-State Tube Tester 667 2N5458   
USA  66 Dyna-Jet Tube Tester 707 6BN8  Complete name: B&K Dyna-Jet dynamic mutual conductance tube tester. 
USA  57 Dyna-Quik 650 6AT6  B&K dynamic mutual conductance tube & transistor tester; add-on panel 610 with rotary swit... 


Further details for this manufacturer by the members (rmfiorg):

Cobra Group (CB units) ~1975tbn_us_dynascancorp_address.jpg

Forum contributions about this manufacturer/brand
B&K (Precision), Dynascan Corp., Cobra Electronics; Chicago, IL and Yorba Linda, CA
Threads: 1 | Posts: 1
Hits: 2965     Replies: 0
Fernsehservice in den USA und in Europa
Wolfgang Scheida
  1 Fernsehservice in den USA und in Europa

Alle ehemaligen Techniker und auch Sammler und Restauratoren von Fernsehgeräten kennen die standardmäßigen Reparaturwerkzeuge wie etwa den Wobbler, Testbildgenerator, Trenntrafo und das Bildröhrenregenerierungsgerät.

Über die Produkte der Fa. Dynascan

alias B&K wurden mir Testgeräte für den Amerikanischen TV Reparaturmarkt ersichtlich wie man sie bisher für Europa nicht kannte. (Zeitraum etwa 1940 bis 1980)


Um unabhängig von der Ausstrahlung eines Fernsehtestbildes zu sein, gab es die B&K Television Analyst Modelle 1075, 1076, 1077B die im wesentlichen einen Flying Spot Scanner (Bildabtaster) also eine Bildröhre mit beschriebenen Strahlraster (nach US Norm) hatten. Davor war ein einfaches Testbild als Folie eingelegt. Eine vor der Röhre befindliche Photomultiplikatorröhre lieferte den Bildinhalt an einen HF Generator mit dem der angeschlossene Fernseher getestet werden konnte.

Zusätzlich beinhaltet dieses Gerät auch noch Signalausgänge (wahlweise für Transistor und/oder Röhrengeräte) zum Test von Zeilentransformatoren sowie Rastersignale zur versuchsweisen Einspeisung in die Fernsehschaltungen.

Was mag der Grund sein weshalb dieses Prinzip in Europa als Testbildgenerator nicht bekannt ist?

Wir kennen nur die ersten Philips und Nordmende Linien-, Punkt- und Gittertestbildgeneratoren mit einem eigentlich höheren Röhrenaufwand als der B&K um die vielen Multivibratoren oder ähnliche Schaltungen realisieren zu können.

Oder war es in den USA erforderlich ein eigenes Testbild zu haben da die Sender keines (oder nur sehr kurz) ausstrahlten?

Bei uns wurde erst etwa um 1985/90 die Aktion rettet das Testbild ins Leben gerufen. Davor war es ebenfalls als stundenlanges Rahmenprogramm für Techniker und geometriebegeisterte Zuseher auf Sendung.

Solche Allroundgeräte die auch noch Zusatzfunktionen können dürften jedenfalls nicht in die Europäische Technikphilosophie passen. (Stichwort Die Tragbare Radiowerkstatt aus 1948).


Der VHF/UHF/ZF Wobbler:

Wie groß die Zahl der TV Techniker diesseits und jenseits des großen Teichs tatsächlich war die einen Tuner/ZF Verstärker wirklich verstehen und abgleichen konnte sei dahingestellt.

Faktum ist aber, dass der ZF Kreis und die Tuner mit Ehrfurcht betrachtet wurden an denen man möglichst nicht "herumdrehen" sollte, da man sonst ein "Problem" hat und wenn überhaupt dann maximal ein Techniker pro Werkstatt als allwissendes Orakel Rat und Abhilfe bieten konnte.

Auch hier zeigt B&K ein Niveau, welches bei Grundig und Normende jener Tage vergeblich gesucht wird:  Der B&K Television Sweep/Marker Generator Model 415

Ein Wobbler mit aufgezeichneter ZF Kurve mit festen Markenfrequenzen (gemäß US-Norm - bei uns wären es die 33,4/38,9 etc.) die als Lämpchen auf der Kurve aufleuchten und wahlweise ein- und ausgeschaltet werden können.

Hier lässt sich ebenfalls nachvollziehen, dass ein Techniker dieses Anwendungsprinzip einfacher beherrschen kann als die bei uns übliche endlose Herumkurbelei am Abstimmknopf.




Erwähnen kann man in diesen Zusammenhang den in Europa üblichen Einbau von 8V Klingeltrafos um die Mobilisierung letzter Reserven aus der Bildröhrenkathodenemission zu erwirken.

Die Techniker in den USA brauchten dazu lediglich einen Adapter mit eingebauten Transformator - den sogenannten TV Britener (auch unter anderem Namen bekannt) dazwischenfügen.

 -  Der Grund:

In Europa hatten wir zumeist 300mA Serienheizkreise - während in den USA Transformatorgeräte mit 6,3 V Parallelheizung üblich waren.


Wenn Sie vertiefende Hintergrundinfos wissen so teilen sie uns diese bitte mit.


W. Scheida 25.2.2006



B&K (Precision), Dynascan Corp., Cobra Electronics; Chicago, IL and Yorba Linda, CA
End of forum contributions about this manufacturer/brand


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