Machlett Factory Direct
Machlett HVD1005 High Voltage Diode Board

Machlett HVD1005 High Voltage Diode Board

New Current Production 

Machlett diodes provide the protection necessary in high output microwave systems, and deliver exceptional performance at surprisingly low prices.

History of Machlett Diodes

The problem: Diodes are being run at a load current higher than they can handle and still maintain the junction temperature within the rating. Heat is generated at the diode junction and must be removed by conduction through the lead wires into the copper track on the PCB. The heat is then radiated into the air by the lead wires and traces. The problem is the board design is such that there is not enough surface area to radiate the heat fast enough so the temperature of the lead wires and traces rises and eventual approaches or exceeds the melting temperature of the solder.

The diodes are typically rated for a maximum operating temperature of 150 °C (572 °F) which is above the melting temperature of the 60/40 solder (375 °F) typically used for this type of product. By the time the solder has reflowed the junctions are well beyond the rating for reliable operation and fail. When a diode junction fails it typically shorts which takes it "out of circuit" and reduces the diode count in the string which decrease the voltage hold-off capability of the assembly as well as increasing heating in the remaining working diodes. Once a diode or two have failed the situation becomes critical and a catastrophic failure occurs complete with arcing, smoke, fire, etc.

The Machlett Solution: Our new design uses a combination of MUCH larger trace area and diodes with a lower forward voltage drop, lower junction capacitance, and lower leakage current, all of which are heat generators. The effect of our design is a lower operating temperature due to less heat generation within the diode combined with better heat removal. We are also using the newer style SAC305 solder (lead-free) which has a melting temperature of 221 °C. These diodes come with a full manufactures quality warranty. No other diode in the industry has a warranty.


Characteristics

Machlett diode prices are the best in the industry.

34 kv 4 Amp "Black Stick" style is the most durable in the industry

26-40 kv "Circuit Card" style diodes have the industry's largest copper traces on the board to handle increased current with total reliability

Metal-oxide varistors (MOVs) are available on all styles for added durability

Precise OEM fit for all systems

New diode board assembly upgrades available for any transmitter


No returns, however defective devices will be replaced free of charge for 1 year from purchase date.

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WHY MACHLETT FACTORY DIRECT?

 
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   Once manufactured by Machlett, vacuum tubes undergo exacting quality control measures to further assure reliability. Power tubes and megatrons are first mounted in test fixtures and burned in for 24 hours. This burn-in helps stabilize the internal operating parameters of the tubes before measurements begin. Each device is then tested and graded for technical characteristics specified by Machlett engineers. Only after a component successfully passes these exacting challenges is it labeled and put into stock to be sold.

The Machlett brand has a storied past. Founded in 1897 as E. Machlett and Son as a maker of scientific glass products, the company was a pioneer in the field of X-ray technology and collaborated with the likes of Madame Curie and other leading roentgenologists. Machlett LogoMachlett Laboratories was created in 1934 to produce X-ray tubes, and grew to become the world leader in the field.

Machlett's product line expanded to include transmitting tubes, and also did contract work for the Atomic Energy Commission. The company was acquired by Raytheon Manufacturing Company, as the conglomerate sought to increase its efforts in the area of microwaves. Raytheon had received a patent for a "high frequency dielectric heating apparatus" in 1945.

Raytheon expanded their military microwave technology into commercial applications, introducing a huge microwave oven for hotel and shipboard use in 1947. The Raytheon Industrial Systems division was formed in Waltham, Massachusetts and subsequently acquired appliance manufacturer Amana. In 1967 the "Radarange," the world's first microwave oven designed for home use, was enthusiastically welcomed by the general public.
As part of a parallel universe, Raytheon LogoPenta Laboratories, another tube manufacturer, was acquired by Raytheon in 1973 and the two operated as separate divisions. In 1988 Connecticut-based Machlett, which had manufactured magnetron tubes for Raytheon's microwave efforts, was sold to Varian and absorbed into the California-based company.

About the same time Penta spun off from Raytheon, becoming an independent entity. The company has become a primary manufacturer and distributor of a wide range of electron tubes, covering broadcast, industrial, research, military, medical and scientific applications. Penta LogoIts California facility is ISO 9001:2008 certified. Penta has affiliated manufacturing entities in Europe and Asia.

In recent years Penta acquired the Machlett brand, and has retained the services of a cadre of highly experienced personnel who trace their roots back to the Raytheon Power Tube division. Penta has reinvigorated Machlett's manufacturing and service operations. The company stands unique as the industry's only microwave systems manufacturer that supplies its own magnetrons.

SHIPPING INFORMATION

USA Shipping $19.95 (USPS)

International $49.95 (USPS)