Results 1 to 8 of 8

Thread: visible cw monitor (for deaf)

  1. #1
    gnuuser's Avatar
    Join Date
    Apr 2020
    Location
    NW Pa,USA
    Posts
    159

    Default visible cw monitor (for deaf)

    Im currently researching and possibly designing a module that can be plugged into the earphone jack of a cw radio with filtering to pick up the strongest signals and convert the code pulses to light a small led.
    so im just throwing this idea out there.
    ( I have a couple of deaf friends who are interested in this idea and want to learn morse code)
    for example on the pixie kits there is an led that lights when the key is depressed but nothing for a received signal.
    but i dont want this to be just pixie! but to be able to be used on any cw radio!

    i know they have decoders packages but thats not what they want.

    i know these have been made before but a quick search doesn't turn up much of anything.
    and a lot of them are based on telegraph (wired alone)
    Im so old dirt was my apprentice

  2. #2

    Default

    I like that idea. What is plan? Are you going to use an active band pass filter centered around 700Hz using an op amp? At the 600 to 800Hz frequency of audible CW, I would guess that you can use a buffer and drive the LED directly without audio wave rectification as the human eye cannot see that fast of a flash. It may appear dimmer than an LED on steady, but I don't think a blindingly bright LED is necessary. Should be a simple and fun project!

    What about using a magnetostrictive-based audio transducer like Terfenol-D to make a device they can hold a finger on and feel the code or place behind the ear like a bone oscillator?
    Last edited by brandon lind; Thu 7th Jan 2021 at 18:37.

  3. #3
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,319

    Default

    Did you say something about not over-complicating things?

    The "UI" could be as simple as a "galvometer" style needle for tuning and its backlight flashing in time with the tuned frequency.
    Attached Images Attached Images

  4. #4

    Default

    So I started in on building an active filter just to see how easy it was to do this. Admittedly, I started with K4ICY's schematic http://www.k4icy.com/cwfilter.htm with the intention of replacing the final filter stage with a buffer to drive the LED while utilizing a single LM324AC quad op amp and, of course, once I started soldering, I opened my drawer and realized I was completely out of 10nF caps.

    Being I have already pulled out all the needed resistors, I will be waiting for amazon to replenish my parts drawer with cheap Chinese capacitors instead of changing resistor values. I have a shed full of old electronics and likely have a bunch of 103 ceramics around here, but I don't have the ambition to scavenge 8 of them.

    If I get bored tomorrow, I might gut some old cobra19's and get this finished. I'm losing interest in hoarding junk for parts and wish I could find someone to strip all my scrap electronics and sort the parts!

  5. #5
    Super Moderator 5B4AJB's Avatar
    Join Date
    Mar 2008
    Location
    Meneou, Cyprus
    Posts
    2,319

    Default

    Quote Originally Posted by brandon lind View Post
    strip all my scrap electronics
    I use a blowtorch for through-hole components, do it outside and forget about the board but the components come off double-time...

  6. #6
    gnuuser's Avatar
    Join Date
    Apr 2020
    Location
    NW Pa,USA
    Posts
    159

    Default

    Quote Originally Posted by brandon lind View Post
    So I started in on building an active filter just to see how easy it was to do this. Admittedly, I started with K4ICY's schematic http://www.k4icy.com/cwfilter.htm with the intention of replacing the final filter stage with a buffer to drive the LED while utilizing a single LM324AC quad op amp and, of course, once I started soldering, I opened my drawer and realized I was completely out of 10nF caps.

    Being I have already pulled out all the needed resistors, I will be waiting for amazon to replenish my parts drawer with cheap Chinese capacitors instead of changing resistor values. I have a shed full of old electronics and likely have a bunch of 103 ceramics around here, but I don't have the ambition to scavenge 8 of them.

    If I get bored tomorrow, I might gut some old cobra19's and get this finished. I'm losing interest in hoarding junk for parts and wish I could find someone to strip all my scrap electronics and sort the parts!
    i know what you mean!
    usually i store equipment for a short time before stripping them out. (but then kick myself in the butt a few weeks after scrapping the chassis)!
    worst part is trying to find old tube based ham equipment that doesn't cost an arm, a leg, and the left nut too!
    too often some sellers put useless junk with 1 or 2 good (Maybe) parts and charge absurd prices for them.
    Im so old dirt was my apprentice

  7. #7

    Default

    Ok, I built it.

    Forgive my mess of a desk. I didn't put the parts on a board as I didn't want to waste one of the few I had left on it so I built it into a ball of components with no board (hot glue may have been involved too). I sound funny as I had my teeth pulled out. I bet if I had found some slower code, it would have been easier to copy the blinking lights.

    https://youtu.be/m14yuta0Tlw

    ...and don't ask why I have a beaker of phenol sitting on my solder station lol

    it does look cool with slower code!
    Last edited by brandon lind; Sun 10th Jan 2021 at 03:11.

  8. #8
    gnuuser's Avatar
    Join Date
    Apr 2020
    Location
    NW Pa,USA
    Posts
    159

    Default

    that looks so cool !
    Im so old dirt was my apprentice

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •