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NCX-1000 update protective circuitry around 8122 or leave it stock?

John VE3PCN All Messages By This Member #76 Hi, ? Anyone modified their NCX-1000 output section to better protect the expensive 8122 tube? ? Several expert source provide direction how to extend the operating life of the tube and to reduce SSB distortion. ? Example is the output section described here: ? HF Circuits for a? Homebrew Transceiver? By Mark Mandelkern, K5AM ? QEX magazine NOV/DEC 2001 ? John VE3PCN
Douglas L All Messages By This Member #77 开云体育 The only thing I’ve done, in my case with my NCL-2000 amplifier which uses two 8122 tubes, is to install a series glitch resistor in the B+ line. ? By the way, 8122 tubes are plentiful as surplus, NOS or good used. They show up on eBay at least weekly. There’s no need to pay the $1200 or so from Burle. They were used by the thousands in civilian and military shipboard transmitters. ? One of my NCL-2000 amps had a blower failure when I got it. The tubes were blackened with heat. I replaced the blower, fired up the amp and believe it or not, the tubes still worked with full output.? I’ve got about 16 spare 8122’s I purchased cheap from various sources, including a NOS matched pair for which I paid about $150. Yet, I’ve never had to use a spare. 73, Doug/WA1TUT? toggle quoted message Show quoted text On Jan 1, 2025, at 3:34 PM, John VE3PCN via groups.io <strupatjp77@...> wrote: ? Hi, ? Anyone modified their NCX-1000 output section to better protect the expensive 8122 tube? ? Several expert source provide direction how to extend the operating life of the tube and to reduce SSB distortion. ? Example is the output section described here: ? HF Circuits for a? Homebrew Transceiver? By Mark Mandelkern, K5AM ? QEX magazine NOV/DEC 2001 ? John VE3PCN

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