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  1. alfa88

    Vacuum Tube Clock

    1st off I tried searching the forum but it didn't seem to work. I tried a google search and found plenty of Nixie clocks. Nixies are not vacuum tubes! Anyhow, I was contemplating maybe building a Nixie clock but instead of ICs or even discrete transistors using vacuum tubes. Has anyone ever...
  2. alfa88

    Need Help Finding Vintage Molex

    My eyes are practically bleeding trying to source 60s-70s vintage, chassis mount, male Molex connectors. Note the side view. The connector slips through a rectangle hole and is locked in place. Pin dia. is 1mm x 1mm, spacing is 4mm .
  3. alfa88

    Solid State Solution for Fried Autotransformer

    A tale of woe. It started when I bought a tube tester years ago. It was in pretty poor shape but it powered up. Somehow when I pushed a few switches(I shoulda read the instructions 1st)and my new toy was dead. So I tossed it into the corner and forgot about it. Fast forward. I unwrapped the...
  4. alfa88

    Seeking Front Panel Silkscreen Alternatives

    Has anyone had success transferring an image from laser printer to a blank painted chassis?
  5. alfa88

    Knightkit 400(A) or Lafayette TE-15 Assembly/Maintenence Manual

    I could use the above. I'm in the throws of restoration of a rusty old wreck and sure could use the assembly manual. I have the user manual but since this was a kit I'd feel warm and cozy with the assembly manual. I do have the user manual; I just don't want to fork over $ for an EBay copy for...
  6. alfa88

    Datasheet or Databook Wanted

    I'm trying to fix a remote controlled ceiling fan. The receiver's triacs got changed and now the motor spins up but several functions aren't doing their thing. I'm sort of guessing that a multi-legged DIP named RH7600RA-3 may have been compromised by the shorted triac and that it's some sort of...
  7. alfa88

    Eico 324 inductors

    I'm restoring an EICO 324 Sig Gen and while I find the documentation is readily available a closer look reveals that the actual inductor values are missing and simply referred to as coil "A" through coil "E". Not that I need to change them but it would be nice to know.
  8. alfa88

    Need Help Analyzing Constant Current Source

    Attached is a schematic of a multimeter section of a SWTP Universal Digital Equipment kit (70s vintage). The circuits in violet are what I suspect are the cause of a malfunction. Fortunately I was able to find a functioning unit and found several discrepancies in the original schematic. The...
  9. alfa88

    Sensistor vs Thermistor

    I've been remastering a 70s vintage digital multimeter kit and I've managed to find replacements for most of the parts but one of the parts is called a sensistor. I sort of assumed that the part is the same thing as a positive coefficient thermistor. Opinions?, Guidance?
  10. alfa88

    Display Lens Source

    I've been restoring some old equipment and run into a brick wall trying to replace the damaged front panel display window. One meter uses Nixie displays and has an amber colored window, the other uses a 7 segment led display and would need a red tint. The thickness should be ~ 0.9mm/.035" . I...
  11. alfa88

    Desire datasheets for obsolete Signetics FFs, Nor

    Does anyone have datasheets for LU321A, LU322B and LU380A? I can glean some info from a schematic but some pin-outs are missing and there'll be some tracing to do. Datasheets might be helpful should I need substitutions. They are JK Flipflops w/S-R, JK Flipflops w/R, and Quad Nor respectively.
  12. alfa88

    Southwest Technical Products Corporation

    Years back I posted a query regarding SWTPC 's Universal Digital Test Equipment. For all you young bucks this stuff was all the rage and they constantly had diy articles in the electronic magazines. Their prices were way better than Heathkit though their finish was somewhat lacking. Anyhow I...
  13. alfa88

    Vacuum in a Can

    In anticipation of my receiving an order of a couple H.P. Friedrichs' books I've been contemplating how to achieve a vacuum for some of the projects. There are those CO2 cartridges so I wondered if anyone has come up with a vacuum cartridge. In lieu of that is there a low cost alternative to...
  14. alfa88

    Sound Bar

    I started looking into a sound bar for my TV but stopped right in my tracks after I realized that there seems to be no provision for linking the TV's remote control power, +/- volume and mute functions. I don't want another remote control to keep track of or to be pressing buttons as if it were...
  15. alfa88

    iPad MDM Software

    I have the task of evaluating Meraki MDM software that will wirelessly manage the school's iPads. The big requirement is that kid's wont be able to remove management profiles that keep the things 'G' rated and location services intact should the iPad walk away. About a year ago Apple came up...
  16. alfa88

    PoE Part Recomendation

    I got a new security camera system from Costco and it seemed like a good idea at first but now I'm having 2nd thoughts. The dongle that comes from the camera has a threaded end with an O ring and one would assume that is for a watertight connection. The problem is the mating side isn't included...
  17. alfa88

    Velleman K8048

    Okay so I got Velleman K8048 the problem is I misplaced the disc that came with the kit. The Velleman website has the driver and assembly directions but that's about it. I'm wondering if there's some tutorial and sample code on the disc. I have no idea where to go from here. Anybody have...
  18. alfa88

    Chicken/Egg Question

    1st. off I'm a newb. with microcontrollers. I've got a Parallax Basic Stamp that I literally blew the dust off of. I was experimenting with turning on and off LEDs and found out that 2 ports were bad. I then found out that the processor in a BS2 is a PIC 16F57. The chip is relatively cheap but...
  19. alfa88

    Semi Newb Advice Request

    I am about to ask for a B'Day gift. I am thinking of getting into Aurdino/PIC controlled things. I want to program a main chip and plug it into the device in question using a minimum amount of 'through hole' parts. 1st. project: the infamous 4X4 RGB Cube.
  20. alfa88

    My Power Supply Saga

    Am I unclear on a concept or what? I'm trying to put together an adjustable 1-15V power supply. I tried a lm317 with a Voltage follower. Didn't work out so I'm going with a LM338. The most I can get out of it is 2A. I made sure the bottleneck wasn't the transformer to bridge section by loading...
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