Search results

Search Forums New Posts
  1. hevans1944

    Morse code led without a micro controller

    It would be tempting to implement this with a fifteen-stage Johnson ring counter, which would be eight dual-D flip-flops (with one flip-flop left over). Maybe use the redundant flip-flop to reset the counter at the end of each SOS sequence, "just in case" a "forbidden state" sneaks into the...
  2. hevans1944

    Morse code led without a micro controller

    The International Distress Signal is a pro-sign consisting of a string of three dits, three dahs, and three dits all sent as one symbol. There is NOT the usual three unit spaces between the three dits and the three dahs, as if these were separate "S" and "O" characters. In other words, Rule 4...
  3. hevans1944

    Morse code led without a micro controller

    Apology accepted, but it was not necessary. Everyone is entitled to their own opinion. And I can also appreciate the desire to make "something from scratch" instead of having to wade into unknown waters trying to program who-knows-what kind of microprocessor. Many years ago, near the end of the...
  4. hevans1944

    Howdy All, I finally made it here

    Ha ha ha. This Extra currently doesn't use ANY of the bands because of the wee antenna problem. The only reason I tested for General and Extra was because I passed Technician first. I think I would have been happy working 2m and up versus long-wave. There are a bunch of repeaters in Dayton...
  5. hevans1944

    Morse code led without a micro controller

    Not "in true diy electronics fashion?" Really? So, what are you using to communicate with us here on this forum? A Tinker Toy set? While it is true that you need a computer, specifically a personal computer, and a programming piece of hardware, specifically a PICkit 3 pod, plus the PIC...
  6. hevans1944

    I need to make two devices compatible with each other

    Good luck finding that here. Have you tried posting to a more specialized forum that discusses satellite remote sensing and communications? That's not anything I know about, but maybe someone here will chime in with suggestions. I assume you want an informed second opinion, not just an opinion...
  7. hevans1944

    Amplification to a constant Vpp

    Yeah! Second that objection! Those cheap skates should look into real-time adaptive audio signal processing with dedicated DSP integrated circuits and programming. This IS the 21st Century! OTOH, I am still waiting for an AI commercial whacker for TV and radio reception... maybe something that...
  8. hevans1944

    Amplification to a constant Vpp

    Still waiting for why, what the application is, and what the OP wants to DO... NOT holding my breath though.
  9. hevans1944

    I need to make two devices compatible with each other

    Methinks you is in over your head on this one, John. The Orbcom OG2 modem is designed for "OEM Systems Integrators" according this blurb on their website. Is that you? Are you a systems integrator coming to a hobby website looking for interface advice? Details on how to interface the Semtech...
  10. hevans1944

    Current sensor for arduino

    Try one of these. Costs a little, does a lot, lasts a long time... easy to interface to PICs or Arduino. There is a (longish) thread here at EP on how to use an Allegro current sensor with a PIC microcontroller for AC sensing, but DC sensing is even easier. Suggest you investigate using the...
  11. hevans1944

    Amplification to a constant Vpp

    Not so fast, Herr Kapp! Ve haf here our newest invention: an hyper-organic fullerine molecule encasing a proprietary high-technology thingamubob that will possibly satisfy the OP's wequest, just as soon as details of the application are posted. Available now, but only in Avogardo's Number...
  12. hevans1944

    Morse code led without a micro controller

    Spot on! The Microchip PIC 10(L)F320 8-bit microcontroller would be ideal for this application. You could even "put it to sleep" between dits and dahs to conserve battery power. Available in a 6-pin SOT-23 surface mount package, you should be able to integrate all the circuitry between the LED...
  13. hevans1944

    Amplification to a constant Vpp

    Let's see if I understand what you are requesting... you have a sinusoidal input "signal" that varies in frequency and amplitude, and you want to produce a sinusoidal output "signal" of the same frequency but with a constant peak-to-peak amplitude. In other words, whatever information might have...
  14. hevans1944

    Electronics help

    You should PM @Ratch for instructions on how to remedy this deficiency.:p
  15. hevans1944

    Howdy All, I finally made it here

    That Jennings VVC would have cost several thousand dollars when it was new, but it was one of two identical VVCs pulled from a surplus Collins military transmitter's final output impedance matching pi-network. This one was connected to the plate of the final (through a DC blocking capacitor) and...
  16. hevans1944

    HMC5883L compass module - Y/Z movement affects each other

    Did you examine the datasheet for the HMC5883L to determine what its maximum cross-axis sensitivity is, and whether that meets your requirements? It is rated ±0.2%FS/gauss, which seems reasonable to me for compass applications. What are you using this for? What do you expect from a transducer...
  17. hevans1944

    Voltage Amplifier

    Except for the high-voltage power transistors (BU 209) with BV(br)ces = 1700 V DC. These "horizontal deflection" transistors have become somewhat rare since television sets no longer require high-voltage fly-back transformers for horizontal deflection of the electron beams in color CRTs, as...
  18. hevans1944

    Howdy All, I finally made it here

    Welcome to EP, Keef. It sez you joined on Mar 1, 2017, but your first post here was yesterday? Jeez, I thought I was good at procrastinating, but that's pretty good. I was licensed as a Novice (KN8UTJ) in 1966 while serving in the Air Force at Kincheloe AFB, MI. Finished my term of enlistment...
  19. hevans1944

    Voltage Amplifier

    Please do! The devil is always in the details though, simple as that may be. Getting an op-amp with a bi-polar ±1000 V DC output isn't exactly rocket science, but it does require some good electrical engineering design. If it can be done while delivering one milliampere (or more) of current...
  20. hevans1944

    Voltage Amplifier

    I don't think it is the same company. Apex Microelectronics Inc. is (and always has been) based in Tuscon AZ and was started in 1980 to satisfy a (then) niche market in high power, high current, op-amps. I don't think they were ever involved in RF amplifiers. Of course Apex is a common enough...
Top