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  1. (*steve*)

    Cannot connect to my router

    You can also use a led and a resistor to determine unambiguously which is the transmit pin. This varies a little depending on whether you have real RS-232 or a logic level alternative (the latter is most common these days). Place a 470Ω resistor in series with a pair of LEDs connected in...
  2. (*steve*)

    Cannot connect to my router

    Yes. This is always the first thing to try when RS-232 is not communicating at all.
  3. (*steve*)

    Microwave oven door hole - outer plastic panel

    That part doesn't get hot. And the microwave energy is stopped by the perforated metal shield.
  4. (*steve*)

    Microwave oven door hole - outer plastic panel

    This is an image of the outside of the door isn't it?
  5. (*steve*)

    Transformer identification

    Trace back the wires you disconnected to where they came from. Maybe the board will have some useful information about voltages. Have you checked for a service manual for the mass spectrometer? It may have information about the transformer used. Was the input voltage on the mass spectrometer...
  6. (*steve*)

    Microwave oven door hole - outer plastic panel

    The perforated metal is the shield. The hole is in a part that's mostly cosmetic. Place some duct tape over the hole. It's probably best not to poke your fingers against the metal shield.
  7. (*steve*)

    Bit Banging I2C for communication between Raspberry Pi and PFC8591

    I don't see anything to set the timing. Have you asked on a specialist forum? (see here) It appears you can configure additional I2C ports on the RPI that will be bit-banged by the OS.
  8. (*steve*)

    Bit Banging I2C for communication between Raspberry Pi and PFC8591

    For true simultaneity you need to trigger all the ADCs at the same time, or to hold the inputs at the same time. A series of sample & hold circuits with a common control would allow you to hold at the signals and then read them one by one. It can be even simpler here with an analog mux because...
  9. (*steve*)

    Bit Banging I2C for communication between Raspberry Pi and PFC8591

    An i2c bus can have 127 slaves on it. The PCF8591 can only have 1 of 8 addresses set, so you can only have 8 of them connected to a single bus. Why not use the single bus the RPI has and whatever standard libraries it has. Surely you can find examples of how to talk to this chip?
  10. (*steve*)

    Inductor coil question

    A picture of the old inductor next to the new one would also be useful.
  11. (*steve*)

    Flashing joule thief - beginner

    Have you heard of scrolling? Granted, the instructions are poor (as is typical of Instructables), but I'd be surprised if the inductor is critical.
  12. (*steve*)

    Flashing joule thief - beginner

    I agree, is hard to read the circuit for the first one. But building the second one without a PCB is likely to be more difficult.
  13. (*steve*)

    Identifying Panasonic microwave diode that connects between capacitor terminals (model: NN-MX25WF)

    Maybe. Just be sure that capacitor doesn't kill you (I'm not joking)
  14. (*steve*)

    Can someone tell me why my powerbar/powerstrip didn't blow up

    The wall outlet is 240V If you plug in the Vcc 120V power board into it, it will deliver 240V to any device you plug into it. It's a great way to blow up 120V devices. The 120V power board may also be dangerous if run at 240V. Pretty bad idea any way you look at it.
  15. (*steve*)

    Hi, have anyebody had trouble building the ELENCO 108 AM/FM RADIO KIT

    I'm sorry, I don't understand the problem? A wire as come loose?
  16. (*steve*)

    Hi, have anyebody had trouble building the ELENCO 108 AM/FM RADIO KIT

    I'm not sure what got autocorrected to "big Spring", but I'd really like to see a new, sharp image of the board showing your soldering.
  17. (*steve*)

    Yaesu FRG-7 vintage budget comms. receiver

    It might be useful to start looking at either the ESR of filter capacitors and/or ripple on the power rails (any the rail voltages) This is pretty simple, and while there's nothing specifically pointing to this as a problem, it will give you confidence in the power supply.
  18. (*steve*)

    Crystal Selection

    1 second per year is about 30 parts per billion. A crystal might have a frequency stability of 0.005%, that's 50 parts per million. So roughly speaking, that's 1000 times worse than you need. The frequency stability is typically specified over a large temperature range (say -45degC to...
  19. (*steve*)

    Crystal Selection

    Those things aren't that accurate to begin with, good luck if you expect to get any sort of accuracy like that. The frequency will drift with temperature way more that that. Just pick an approximately correct crystal and see how you go. If that device was any good there would be a means to...
  20. (*steve*)

    Hi, have anyebody had trouble building the ELENCO 108 AM/FM RADIO KIT

    You need to follow the instructions for getting the correct windings of the coil in circuit with the correct phasing. Also, an updated *sharp* image of the big Spring your improved soldering would be great.
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