Search results

Search Forums New Posts
  1. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Please post a schematic of the output of the radio connected to your LM386 circuit and fix the problems:
  2. Audioguru

    Multimeter testing led

    My Fluke multimeter has a maximum output voltage of about 3.0V for a diode test. It lights and shows forward voltage for most colors 1.8V to 2.5V but not some white and blue LEDs that have a forward voltage of 3.5V.
  3. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Why are you here on this English language forum where you do not understand what I say and I do not understand what you say? You do not know the simple basics of electronics and are trying to make a radio that you never learned anything about. You do not know the simulation program and are also...
  4. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    You make too many mistakes:
  5. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    The IF carrier frequency is still not 10.7MHz. C3 still does not connect to ground. You wrongly calculated the value of C6 so it cuts most low and mid-low audio frequencies. The polarity of C7 is probably backwards.
  6. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Why am I correcting your errors when the book schematic I post shows you how to do it?
  7. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Why is your new carrier frequency 10MHz instead of 10.7MHz? Why is the audio modulation frequency 3MHz instead of 1kHz? Why does your 'scope show 5MHz? Why is the audio output from the diodes still shorted when I showed you many times how the output from one diode is grounded and the output from...
  8. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Michael, you do not know what you are doing. I am ready to quit trying to help you.
  9. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    You made your schematic with the parts too far apart then the text is too small to see. Also you did not right click on the schematic part of the simulation then select "View" then select "Zoom to Fit". The large sinewave that is slowly reducing its level is 667kHz. Why? You still have some...
  10. Audioguru

    Inserted 9v battery wrong way into fire alarm, expected damage?

    Maybe the smoke detector has no 9V battery jack designed to prevent contact when the battery is backwards, but has just two cheap contacts.
  11. Audioguru

    4017 IC

    Some of the LEDs in my solar garden lights have a very short clear case with a rounded top that has the chip very close to the top. Then its light is VERY wide angled.
  12. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    I am glad to see that you turned around the diodes so that are not conducting all the time. Now you have the anodes of the diodes not connected to the transformer. Also you have coil L4 and C10 shorted to the positive supply with C5. The schematic does not have a positive supply so it will not...
  13. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Today, where will you buy 10.7MHz IF transformers and a 10.7MHz discriminator transformer or a 10.7MHz ratio detector transformer? They might have the tuning capacitor inside. Crystal filters replaced IF transformers years ago. You want to know the values of WHICH rc? You posted a txt file...
  14. Audioguru

    Multimeter low voltage diode check output upgrade?

    It will light an LED. Then you measure the forward voltage across the LED with a voltmeter. Do not connect the LED with backwards polarity.
  15. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    Will you buy 10.7MHz transformers and a discriminator? They were sold 40 years ago but not today. Today an FM radio uses crystal filters instead of transformers. Digikey has 10.7MHz IF bandpass crystal filters and crystal filter discriminators.
  16. Audioguru

    Inserted 9v battery wrong way into fire alarm, expected damage?

    My smoke detectors are made so that a 9V battery cannot physically be installed backwards.
  17. Audioguru

    Multimeter low voltage diode check output upgrade?

    My Fluke multimeter uses a 9V battery and its diode test lights up only some LEDs dimly. The current is so low that the forward voltage display is useless. Use a new 9V alkaline battery with a 360 ohm series resistor instead.
  18. Audioguru

    Hello, can somebody help wich transistor is like bfg520

    I did not say anything resonates at 5.1MHz. I said your signal generator in the simulation wrongly produces 5.1MHz instead of the correct 10.7MHz. Your schematic has more errors. The black and white schematic I posted is correct and widely used. It clearly shows the tuning capacitors parallel...
  19. Audioguru

    BMS for Lithium Iron phosphate battery bank LiFePo4

    The very important specification called "Capacity" is missing from this cheap Chinese junk. It gives the spec's for a "protection circuit" but does not say it has one. EDIT: Sorry. I see that it is a BMS, not a Lithium ferrous battery. Some of us say "protection circuit" and others say "BMS".
  20. Audioguru

    The Fathom-Sound Project

    Thanks for making some corrections I recommended. But I repeat, "Your LM386 mixer and power amplifier is missing the important series RC at its output that is shown on every circuit in its datasheet that prevents high frequency oscillation and heating." The ICs need important supply bypass...
Top