MRD4-SearchScreen.png' alt='3 Phase Motor Rewinding Software Engineer' title='3 Phase Motor Rewinding Software Engineer' />Back to AC Adapters and Power Supplies Table of Contents.Introduction Scope of this Document This collection of information deals with the troubleshooting, repair.Tenders in Andhra Pradesh, E tender Andhra Pradesh, Andhra Pradesh tenders, Andhra Pradesh government tenders, tenders in Andhra Pradesh, Andhra Pradesh govt tenders.Phase Motor Rewinding Software Engineer' title='3 Phase Motor Rewinding Software Engineer' />Convert Tube Receivers to Solid State.Charles. I used an LM 3.The conversion was so simple that I never documented the process.And Ive never had to make any subsequent repairs, either.Once I found that I could make the local oscillator work and track properly with a JFET soldered underneath the 6.C4 socket with a 1.I figured the rest would be easy.And for the most part, it was.For the RF and IF amplifiers, I basically tied the Drain of each 4.That August, two months after losing my job, death took my favorite uncle.Weeks later on Labor day, it came for my mildmannered orange tabby.Ww3Nq.gif' alt='3 Phase Motor Rewinding Software Engineer' title='3 Phase Motor Rewinding Software Engineer' />MOSFET to the previous 6.BA6 Plate connection, G1 to Grid, and Source to ground through a red LED and a parallel RF bypass capacitor.The LED serves two purposes.It lights up so I can say my receiver glows in the dark and therefore is real, and more importantly, it establishes a 2 volt fixed bias on the Source.This bias is needed to drive the MOSFET to cutoff when G2 is brought down to zero volts through AGC and manual RF gain control action.I think I put about 1.LED conducting, regardless of actual Source current, which varies with AGC action.So, Vdd for each MOSFET is fed through each IF transformer winding, just like Plate voltage was for each 6.BA6 in the receivers original design.I think making plug in modules for tube replacements would be difficult.Tubesters and Fetrons were attempts at doing this in the past, and only enjoyed limited success for a variety of reasons.Sometimes its better just to re design a specific circuit based on the general needs of the circuit, not so much the specifics of the active devices originally used.For example, I would be more inclined to design an audio amplifier using an op amp or two, configured for the impedances and voltage gain required, rather than try to design the solid state equivalent of a 1.AX7 that I wish to replace.But getting back to radios, the inputoutput.I would expect such conversion would.MOSFET input impedances are at least as high, and may even be higher, than those of small signal triodes and pentodes of the type used in HF receivers. Corporation Tax Payment By Instalments To Watch . I have not had ANY crosstalk, dynamic range, or intermodulation distortion issues after doing my solid state conversion.I did initially when I used a 4.MOSFET 6. BE6 substitute as a mixer, but those issues vanished after I replaced the 4.LM1. 49. 6 doubly balanced mixer IC.
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