Search:

Type: Posts; User: neazoi

Page 1 of 20 1 2 3 4

Search: Search took 0.07 seconds.

  1. Replies
    0
    Views
    101

    Closed: Hantek6254EU does it worth it to buy?

    Hi, I consider buying for a friend the Hantek 6254EU oscilloscope.
    http://www.hantek.com/en/ProductDetail_12169.html

    He owns an HP54520A but it's PSU has broken down. He used it for HF work ...
  2. Closed: Re: 1200 baud data transfer over audio passband of cellphone. Is that possible?

    Just a simple audio cable connected to the hands free socket of the mobile phone and on the other side to the microphone and headphones jacks of the PC. There is no acoustic coupling. Bell 202 is the...
  3. Closed: Re: 1200 baud data transfer over audio passband of cellphone. Is that possible?

    I could possibly, but "regular" users couldn't.
    Anyway I have just tested it. I connected a smart phone from it's hands free port to the PC mic and phones. then I called the smart phone from a land...
  4. Closed: 1200 baud data transfer over audio passband of cellphone. Is that possible?

    1200 baud data transfer over audio passband of cellphone. Is that possible through the use of their codecs? Has anyone actually tried it? There are videos about comms on 300 baud but how about 1200...
  5. Replies
    0
    Views
    171

    Closed: Micto-tel 1200 receiver additional help

    Hi I did not know how to post in this thread after so long https://www.edaboard.com/showthread.php?382299-micro-tel-1200-service&highlight=1200 so regarding this receiver, I noticed that there is no...
  6. Replies
    40
    Views
    3,035

    Closed: Re: HP 54520A Blown Fuse Problem

    UPDATE
    I think I have found the problem. It seems to be indeed these gas discharge tubes. Then I remove both of them completely there is no blown fuse anymore. I have never thought these can fail,...
  7. Replies
    40
    Views
    3,035

    Closed: Re: HP 54520A Blown Fuse Problem

    Can it be the gas discharge tubes near the big electrolytics? These are the only components I have not changed in the HV side. If they fail they could short circuit the output and thus blow the fuse....
  8. Closed: Re: How to unballance this single balanced mixer?

    I suspect that if I apply 9v DC through a limiting resistor (say 1k?) in the left points of the diodes, one diode will conduct DC to ground whereas the other not. So it will be effectively one diode...
  9. Closed: How to unballance this single balanced mixer?

    Hi, how can I unbalance this single balanced mixer so that it can detect AM on down conversion or produce AM if used in up-conversion in a direct conversion transceiver?
    LO is connected to the...
  10. Replies
    28
    Views
    1,599

    Closed: Re: Passing both DC and pulses through a toroid?

    So a big transformer core that is saturated less easily, would allow DC to pass from the primary to the secondary?
    That's really new to me, if I understand this ok!

    - - - Updated - - -



    If...
  11. Replies
    28
    Views
    1,599

    Closed: Re: Passing both DC and pulses through a toroid?

    Thanks a lot!
    Please help me understand the thing with my second question, if the DC is in one direction in one primary winding (assumming no saturation) and if my 0-5V edge is at the opposite...
  12. Replies
    28
    Views
    1,599

    Closed: Passing both DC and pulses through a toroid?

    Hi,
    Suppose I have a toroidal core and I wind one turn of wire through it, as my primary.
    My secondary is also one turn through this core.
    For the next description assume no core saturation at...
  13. Replies
    2
    Views
    275

    Closed: At45db041b vs at45d041

    Hi I have a AT45DB041B connected to the ICSP of the atmega644 and stores data ok.
    I am trying to replace it with the through hole AT45D041 which seems identical to me apart from the 5v requirement,...
  14. Replies
    40
    Views
    3,035

    Closed: Re: HP 54520A Blown Fuse Problem

    I have removed the common mode choke and put wires in it's place. Fuse still blown :( At least the thermistor did not blow, but it may be lust luck.

    I remember I had tested the external RFI...
  15. Replies
    40
    Views
    3,035

    Closed: Re: HP 54520A Blown Fuse Problem

    Hi,
    the problem was not the bridge :(
    after a few seconds or tens of seconds it blows the fuse.
    I have located the problem in it's switching mode PSU module, because when I disconnect it from...
  16. Closed: Re: FSK 1200baud discrete "modulators". What do you think?

    Hm...
    So 3 basic problems have reported to me. One is the phase (which based on the paper, could be ignored with suitable detection scheme), the other is the effectiveness of the detector when...
  17. Closed: Re: FSK 1200baud discrete "modulators". What do you think?

    I should have posted the whole "modem" block diagram before I got you into trouble. Here it is. The RX will use two narrow filters and a simple detector which will convert audio tones to voltage...
  18. Closed: FSK 1200baud discrete "modulators". What do you think?

    Hi
    I want to investigate the possibility of making a discrete FSK 1200 baud modulator operating from 5v and connected to the TTL UART of an MCU. The circuits have to be made as simple as possible...
  19. Closed: Re: Reducing 10K lineat potentiometer to 1K, what about lineatity then?

    are you sure? This is the circuit. The mentioned linear pot/resistance will replace the 47k log one in the circuit.
  20. Closed: Reducing 10K lineat potentiometer to 1K, what about lineatity then?

    Hi I have a 10k linear potentiometer with center detent (lock).
    If I connect a 1k parallel resistor to the potentiometer ends (carbon track ends), I could in theory reduce the value of the...
  21. Replies
    12
    Views
    2,788

    Closed: Re: USB to PS/2 adapter, how does this work?

    I have 3 of these converters, 2 of them are actually for mouse. They all worked with one of the two keyboards. In the other keyboard none of them worked. If they had a converter inside them, I would...
  22. Replies
    12
    Views
    2,788

    Closed: Re: USB to PS/2 adapter, how does this work?

    I have tested it. I took a USB keyboard that I had connected to a PC through a usb to PS/2 adapter and pluged it in the project. It has been powered up (three leds are on in the beginning and then...
  23. Replies
    12
    Views
    2,788

    Closed: Re: USB to PS/2 adapter, how does this work?

    The purpose would be that every USB keyboard could work in the PS/2 port.
    I wondered so, because if that was the case, then USB keyboards (not-combo) would work in a PC PS/2 but not in my project.
  24. Replies
    12
    Views
    2,788

    Closed: Re: USB to PS/2 adapter, how does this work?

    Well this are great news for the project. If the intelligence is inside the keyboard, then USB keyboards can be used with this project IF they support the PS/2 protocol.
    I guess the simplest thing...
  25. Replies
    12
    Views
    2,788

    Closed: USB to PS/2 adapter, how does this work?

    I have an MCU project that accepts PS/2 keyboard. I want to investigate if I could use USB keyboards as well with it using these USB to PS/2 adaptors.

    I think that the conversion from USB protocol...
Results 1 to 25 of 500
Page 1 of 20 1 2 3 4