Eimac

  

©  Tube Collection Udo Radtke, Germany  2015-11-05

Der Name Eimac geht auf die Firmengründer Bill Eitel und Jack McCullough zurück, die im Jahre 1934 das Unternehmen Eitel-McCullough Corp. in San Bruno, Californien , USA, gründeten.

Beide arbeiteten zuvor im Unternehmen des bekannten Röhrenherstellers Heintz & Kaufmann. Sie beschäftigten sich bei H&K bereits mit der Entwicklung einer Senderöhre für den Markt der Funkamateure, also einer Röhre, die bereits bei geringer Spannung eine hohe Leistung erzielt. Daraus entstand die HL-354.

Ihr erstes Produkt unter dem Namen Eimac war die Röhre 150T. Man entwickelte eine ganze Reihe interessanter Röhren und belieferte damit überwiegend das Militär in der Radartechnik.

Ab 1947 betrieb man auch eine eigene Radiostation in FM-Betrieb.

Inzwischen wurden die Fabrikanlagen zu klein und man zog nach San Carlos. Die Fabrik dort wurde am 16.04.1959 eingeweiht.

!965 fusionierte Eimac mit Varian und hieß dann Eimac Division.

 

 

1995 kaufte Leonard Green & Partners das gesamte Geschäft von Varian auf und bildete die Communications & Power Industry (CPI), die auch heute noch in vielen Geschäftsfeldern tätig ist.

  
 

While employed by the small San Francisco, Califonia, manufacturing firm of Heintz & Kaufmann, Bill Eitel and Jack McCullough  convinced company president Ralph Heintz  to allow them to develop a transmitting tube that could operate at lower voltages than those then available to the amateur radio market, such as the RCA 204A or the 852. Their effort was a success and resulted in production of the HK-354. Shortly after in 1934, Eitel and McCullough left H&K to form Eitel McCullough Corp. in San Bruno California.

The first product  were transmitting tubes with the high performance and stable design features that were required by the Ham radio community. The first tube produced under the trade mark "Eimac" was the 150T power triode. Under the leadership of the founders, Bill Eitel and Jack McCullough, the company grew and expanded to meet the needs of the U.S. military during World War II.. The new company thrived during world war II by selling tubes to the U.S. military for use in radar equipment.

Beginning in 1947, Eimac operated FM radio station from their plant.

In need of more space, the company moved to San Carlos. Eimac's San Carlos plant was dedicated on April 16, 1959. In 1965, Eimac merged with Varian Associates and became known as the Eimac Division.

Eimac continued to advance the technology and developed modern, high-power ceramic tubes which incorporate innovative Pyrolytic graphite grids for short-wave and UHF television broadcast. Regarded as a technical innovator, Eimac has become the worldwide leader in broadcast tubes. Eimac designs and produces power tubes for broadcast, communications, radar, industrial heating, semiconductor processing, science and medical applications, with customers located in virtually every country in the world. All Eimac tubes are made in the U.S.

In 1995, Leonard Green & Partners  purchased the entire Electron Devices Business from Varian and formed Communications & Power Industries (CPI)

Eimac, now part of CPI's Microwave Power Products Division

Typen / Types:        (Typenschlüssel / Type Numbering System)   >> 

2-50A, 2-450A, 2X1000A,

3CW40000A5, 3CX800A7, 3CX1500A7, 3CX2500A3, 3CX2700A3, 3CX3000A1, 3-150ZG, 3-200A3, 3-400Z, 3-500Z, 3-1000H, 3-1000Z, 3C24,

4-65A, 4-125A, 4-250A, 4-400A,

4CS250A, 4CX300A, 4PR400A, 4CX250M, 4CX250R, 4CX5000A,

4PR60A, 4PR60C, 4PR400A, 4X500A, 4PR1000A,

5-500A, 5CX1500A, 6C21, 15E, 25T, 35T, 35TG, 50T, 75TL,

100T, 100TH, 152TH, 254W, 250TH, 254W, 304TL, 450TH, 450TL, 527, 8965,

RX21, VT-127A, VT-129, VT-158, Y-180, YU-191A,

rot = Foto eingebaut,  blau = Röhre in Bearbeitung, schwarz oder nicht gelistet = Type fehlt noch
red = tube + picture OK, blue = Tube in process, black or not listed = type missing


 
2-50A 2-450A  

 
2X1000A   3CW40000A5

3CX800A7 3CX1500A7 3CX3000A1

   
    3-150ZG

3-200A3 3-400Z 3-500Z

3-500Z 3-1000H 3-1000Z

 
3C24 3C24  

 
  4-65A 4-125A

4-250A 4-400A 4-400A inside

4-400A inside 4CS250A 3CX2500A3  Var.1

3CX2500A3  Var.2 4CX205R 4CX250M

4CX300A 4CX300A 3CX2700A3

4PR60A 4PR60C 4PR400A

4PR1000A 4X-500A 4CX5000A

5-500A 5CX1500A 6C21

 
15E 25T  

 
  35T 35TG

50T 75TL 100T

 
100TH 152TH  

 
  250 TH = VT-220 254W

304TL 450TH 450 TL

527 8965 RX21

Type 527

They were designed to take the place of the VT127A family of ring oscillators.  They were extensively used through the Korean war.  I think they could get a million watts out of a pair in pulse.  Lots of filament current.

They were on the military “preferred” lists for 1944 and 1945.

 The Navy had an SK-1M and an SR radar, each using four 527s mounted parallel to each other in the midst of tuned / resonant lines.  The four would put out a megawatt (peak pulse) at 210-225 MHz.  There were another four in an AN/TPS-15 radar (the code sounds like a ground-based system).

Eimac, which at the time was mostly skilled artisans rather than analytic types, went through forty-some prototype designs before coming up with the final product.  Postwar, they weren’t particularly interested in reproducing 527s, so Penta Labs, formed in Korea times, did a run of them.

 

VT-127A VT-129 Var.1 VT-129 Var.2

VT-158 Zahl Radar Y-180 YU-191A

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