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  1. CDRIVE

    VHF booster

    Personally, I don't know why anyone would bother building one. They're very inexpensive to purchase (off the shelf) but if you insist on building it post the schematic. Edit: Oops, I just saw your location. You folks are still driving around in 1957 Chevy's that look like they just rolled off...
  2. CDRIVE

    12v Switch Mod

    Is your turn signal switch a left - right rocker switch?
  3. CDRIVE

    Valve (tube) amplifier schematic help

    I looked it over and all seems correct except the missing filter cap. Chris
  4. CDRIVE

    Valve (tube) amplifier schematic help

    I haven't looked it over thoroughly enough to answer your second question. RE, your first question: You can power the filament from AC, DC and pulsating DC but only filtered DC is acceptable for the plate supply. Unless you like the sound of Ummmmmmmmmm! Chris
  5. CDRIVE

    What value of resistors do I need and a sanity check

    Which is why I bailed from this topic early. This thing is a liability attorney's wet dream. :eek: Actually, this is only partially true. If there isn't a deep well to suck dry they're not interested at all. Anyone here have a deep well? :rolleyes: Old Canadian expression: CYA! ;) Chris
  6. CDRIVE

    Motor control diy

    Be careful with your microswitch selection. Many switches are rated for AC current with no DC rating listed. The DC current rating will be about 1/3 the AC rating but this is a guess. Input welcome. ;) Chris
  7. CDRIVE

    Motor control diy

    Here's a few things to keep in mind.. There is no way to guarantee that the cord isn't going to twist. It probably will. All target transits that I've used moved at least half the speed that yours will be. They also bobbed up and down and swung laterally as they traveled. They also twisted...
  8. CDRIVE

    Valve (tube) amplifier schematic help

    Your Bridge doesn't have a filter cap. You're feeding the amp 120Hz pulsating DC. BTW, glad to see you're not trying to power it from a 9V battery. The filaments would suck it dry in short order. Chris
  9. CDRIVE

    Valve (tube) amplifier schematic help

    Then his circuit should drive it OK if the input level is kept below 80mV My Dad's old SX42 has a humorous history. Remind me to recount it in the members lounge. It's a hoot! ;) Believe it or not there's a segment of our society that fervently believe that our micro technology is not a...
  10. CDRIVE

    Valve (tube) amplifier schematic help

    Actually 1 one millionth of a Farad = 1uF; not small. Since a Farad is huge we generally work in uF, nF and pF. Tube inter-electrode capacitance is in the very low pF range. Same applies to BJT and FET junctions. However, since Vacuum Tubes and FETs are high impedance devices a very small...
  11. CDRIVE

    Valve (tube) amplifier schematic help

    Yes, to some extent. When I added the output network to my spice run the output started clipping on the positive excursions. I'm guessing that the input Z to the power amp is going to be about 10KΩ but I'm not an expert on guitar amps, so it's a guess. My point being that VR3 would have to be...
  12. CDRIVE

    need help with latching relay circuit

    Yes, no problem. Gotta hit the sack. Chris
  13. CDRIVE

    Valve (tube) amplifier schematic help

    This amp will provide the biggest bang when the input Z to the power amp is >=100K. That doesn't mean that it won't drive a 10K input though. It will but not without distortion. A low input Z like 600 Ohms would be totally out of the question though.
  14. CDRIVE

    need help with latching relay circuit

    With the proper relay the Pololu is easily capable. I was too lazy to draw the Pololu so I just copied and pasted it but it's clear enough for you to see the relay interface.
  15. CDRIVE

    Valve (tube) amplifier schematic help

    Spice is a simulation software. It enables the user to animate or simulate a schematic as though it was a physical circuit. The simulation results were impressive with an unloaded voltage gain of 60. The 12AU7 still rocks! The design will do what you want it to do. ;) What device will this...
  16. CDRIVE

    Valve (tube) amplifier schematic help

    I couldn't resist spicing your circuit. Probably the deep affection and memories that tubes bring to mind. My spice model didn't allow for a 9V filament, so the results are with a 12V filament voltage. Anyway with a 2KHz 100mV signal input it output 6VPP. This measurement was made directly to...
  17. CDRIVE

    Valve (tube) amplifier schematic help

    Not exactly. A 12V car battery can deliver enough current to turn a 1/2 inch drive socket wrench white hot and weld it to the chassis.
  18. CDRIVE

    Valve (tube) amplifier schematic help

    This is possibly the most politically incorrect statement ever put to print. It's also one of the funniest and most honest things ever put to print! Hell, no one can deny it drives the point home! ;) Steve, if this question is ever asked again don't be surprised if you find your writings being...
  19. CDRIVE

    Motor control diy

    Thanks for pointing that out Kris. I've modified that schematic to reflect a 1A fuse. This is one of those times that I wish I had paid more attention to the transit mechanics of some of the ranges I've used. For one thing, you're point of cable sag has me thinking about that. I do know that...
  20. CDRIVE

    Motor control diy

    I liked Kris's idea of having both limit switches at the Home end but I didn't think it could be done until I started drawing this. Give a look. Chris
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