Category Archives: Uncategorized

MSF Clock be wrong – RPI MSF transmitter

A friend of mine was asking me about MSF time reception and I realised I only knew some of the basics.  So this sent me on  a hunt for more information.

In the UK the MSF tme signal is sent on a carrier of 60khz from a transmitter in Anthorn Yorkshire with a radiated power if 17KW

17KW sounds large, but this is at 60 Khz, the efficiency of ariels less than 2.5Km (a half a wavelength of 60Khz) long with all round  coverage is going to be much less than 1, probably a lot less than 1. The old Time Signal transmitter at Rugby was in the order of 200KW. I can only assume the new transmitter is of a similar power to get a ERP of 17Kw.

After a little looking around, I discovered the web site of Andy ( who has made a MSF transmitter for 60Khz using a Pc’s sound card using the third harmonic of 20Khz to produce a 60 Khz signal and written the Python code to encode a date time into the MSF protocol.

So with most of the heavy lifting done, I started to think about what I had to hand. Raspberry Pi’s…

My first thought was using the frequency generator built in to the PI to give the 60Khz as used in many PI transmitter projects , but  there were limitations in trying to get 60Khz. So the next thought was a PWM output. A bit of googling gave me the formulae for the frequency of the hardware PWM on a PI


PWMrange is the number of “levels” you can specify for the PWM signal.

After some experimenting I found that you could set the range really small e.g. 2 Which is great if you sent the PWM a 0  it goes off. If you send it a 1 you get 50/50 Mark Space, ideal.  Setting the pwmClockDivisor to 160 gives a 60Khz output.

The Wiring PI Wrapper for Python supports this setup. So setting  the hardware PWM is a case of

io = wiringpi.GPIO(wiringpi.GPIO.WPI_MODE_PINS)

The wiring Pi for Python setup is detailed here

# This script uses PWM on GPIO PIN 18 to transmit an MSF timecode
# Save it as somewhere on your Pi.
# Run it with 'python'
# Requires the Wiring Pi Python Library
# Based on Audio MSF code from 
# by
# PWM output, Frequency and DateTime Code Added by Derek Woodroffe 

# Set the time/date to transmit below.
# The date time startes at the datetime you set regardless of local 
# clock settings
# Use groundhogday=True to repeat the same "day" every 24 hours.
# Your clock(s) should have set its time by around minute 5.
# Some clocks only look at MSF data every 12 hours.
# The day of the week is automatically set to the correct value

import time
import math
import wiringpi
import datetime

#----------------- Carrier  Frequency ------------------------------
#UK tested, others un-tested not sure about the modulation
Freq=60000 #60Khz UK/Japan - 66.66Khz Russia - 77.5Khz Germany/Taiwan

#----------------------- Set inital time ---------------------------
#start with a defined datetime
mmfdt = datetime.datetime(2019,4,1  ,6,1) #datetime year,month,day,hour,min
#Run with current time 
#mmfdt = 
#run 1 hour in the future
#mmfdt =,0,0,0,0,1,0) #timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]])

#------------------------ Groundhogday -----------------------------
#repeat after 24 hours.
#dont repeat 

#------------------------ Parity -----------------------------------
# Set to 1 to transmit proper parity bits
enableparity = 1

def carrier_on(length):
def carrier_off(length):

def minutemarker():
def send01():

def send11():

def send00():

def send10():

bcdlist= [80, 40, 20, 10, 8, 4, 2, 1]

#setup PWM GPIO pin 18 (pin1) Hardware PWM at Freq
#pwmClock divisor=19.2e6/2/Frequency

io = wiringpi.GPIO(wiringpi.GPIO.WPI_MODE_PINS)


    year = mmfdt.year
    month = mmfdt.month
    dayofmonth =
    dayofweek = (mmfdt.weekday()+1) % 7       #0 = sunday, 1 = monday etc.
    hour = mmfdt.hour
    minute= mmfdt.minute

    # Ignore the '0' element in the list as it confuses matters
    # with the timecode
    timecodeA = [0] * 60
    timecodeB = [0] * 60

    # Convert the year to BCD and store in the correct place in the timecode
    temp = year
    for i in range(17,25):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            sum += 1;
            temp -= bcdlist[bcdindex]
        bcdindex += 1

    # Work out the parity bit for 17-24
    if (sum % 2) != 1:
        timecodeB[54] = enableparity

    # Now do the month
    bcdindex=3  #starts at 10
    temp = month
    sum = 0
    for i in range(25,30):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            temp -= bcdlist[bcdindex]
            sum += 1
        bcdindex += 1

    # Do the day of month
    bcdindex=2  #starts at 20
    temp = dayofmonth
    for i in range(30,36):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            temp -= bcdlist[bcdindex]
            sum += 1
        bcdindex += 1

    # Work out the parity bit for 25-35
    if (sum % 2) != 1:
        timecodeB[55] = enableparity

    # Do the day of week
    bcdindex=5  #starts at 4
    temp = dayofweek
    sum = 0
    for i in range(36,39):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            temp -= bcdlist[bcdindex]
            sum += 1
        bcdindex += 1

    # Work out the parity bit for 36-38
    if (sum % 2) != 1:
        timecodeB[56] = enableparity

    # Do the hour
    bcdindex=2  #starts at 20
    temp = hour
    sum = 0
    for i in range(39,45):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            temp -= bcdlist[bcdindex]
            sum += 1
        bcdindex += 1

    # Do the minute
    bcdindex=1  #starts at 40
    temp = minute
    for i in range(45,52):
        if temp >= bcdlist[bcdindex]:
            timecodeA[i] = 1
            temp -= bcdlist[bcdindex]
            sum += 1
        bcdindex += 1

    # Work out the parity bit for 36-38
    if (sum % 2) != 1:
        timecodeB[57] = enableparity

    #Bits 53A - 58A should always be 1
    for i in range(53,59):
        timecodeA[i] = 1

    print(str(year).zfill(2) + "-" + str(month).zfill(2) + "-" + str(dayofmonth).zfill(2) + " " + str(hour).zfill(2) + ":" + str(minute).zfill(2)+ " - " + str(dayofweek)  )
    #print("A bits: " + str(timecodeA[1:]))
    #print("B bits: " + str(timecodeB[1:]))

    # Now play the timecode out
    for i in range(1,60):
        if (timecodeA[i] == 1) and (timecodeB[i] == 1):
        elif (timecodeA[i] == 0) and (timecodeB[i] == 1):
        elif (timecodeA[i] == 0) and (timecodeB[i] == 0):
        elif (timecodeA[i] == 1) and (timecodeB[i] == 0):

    mmfdt = mmfdt + datetime.timedelta(0,60) #timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])
    if (groundhogday):
      if (mmfdt-mmfdts>datetime.timedelta(1)):
        #restart day
        print ("RESTART DAY")


io.pwmWrite(PIN,1) turns on the 60 Khz and io.pwmWrite(PIN,0) turns it off.

I replaced all of Andy’s Sound Card Code with functions that mimicked the operation, but used the PWM commands above and a sleep to give me the correct on/off times (yes, sleep is inaccurate, this could be improved)

Adding a short wire to GPIO 1 (PIN18) and placing this near an MSF clock, worked… (it was 4 in the afternoon, and not April 1st 2019)

But if you want some fun, this close is probably not enough 🙂

Note: Transmitting on this frequency is Illegal and It is possible to affect all sorts of equipment that uses MSF. The transmitter below has a range of only a few feet and so is unlikely to cause any unexpected effects, but don’t do this where there is  any medical or industrial control equipment that may use the time signal.

Oh, and your neighbour may get quite miffed if his alarm clock goes off at the wrong time…

So adding some power..

I made an X of 300mm strips of MDF and wound 100Turns of 0.3mm enamelled wire around the structure.

This I drove from a MC4428 mosfet driver. Using both channels together gives a full bridge drive of up to 1.5A and can run up to 24V.

C1 will need to be modified to get your coil in tune. Tuning can easily be done by monitoring the Cap to coil connection and varying the value of C1 for maximum voltage. Beware that the voltage on C1 can get to about 100V when in tune, so keep it away from your PI#s GPIO

(And other things too)

The Circuit generates about 1W of power, but remember the ariel is only a fraction of the 2.5Km dipole required for 1:1 ERP , so the actual  ERP is much lower. Mine will “correct” clocks time at a range of about 4-5 Meters.


Key-In-The-Dark Torch

Key in the dark has been played in Scout groups and youth groups for as long as I can remember.

The idea of the game is one Scout is blindfolded and sat on a chair with a large set of keys underneath. He is “armed” with a torch. Usually a number of obstacles and places to hide are set up around them.  The rest of the scouts need to stealthily get to the keys without the Scout shining the torch on them.  If they are hit by a touch beam they are defined dead and have to either sit out the game, or start from the beginning again. The idea is that any sound made by the scouts in their approach means a torch shone their way.

Of course in practice a torch is not the ideal “weapon” although rules are that the torch is only to be used intermittently, it is basically an infinite resource and is usually shone around with abandon. Plus the operator being blindfold, they have no idea if the touch is on or off. The other main problem is that the torch beam diverges so much that multiple asalients can be cought at once.

So I started to look at alternatives. As 5W leds are cheap I thought of one of these as a source, combined with a 10 x 70mm focal length lens from a watchmakers eyeglass (loupe) in a 20mm tube. I could get a pretty narrow, bright beam.

Mounting the LED on a piece of copper allowed for any heat from the led to escape. 

Of course, I needed a way of switching this, so I used a MC4427 1.5A mosfet driver, purely as it was a single chip solution and mainly as I had one to hand.

I dead bug soldered it, as there were only 4 connections. and glued the driver to the back of the heatsink.

I had had the idea of “charge” to keep down the number of flashes, the idea being that every press of the button would freeze out the user for 0.5 Seconds. To show this, I thought of a number of neopixels along the barrel. So these were attached with some acrylic rings to spread the light out 

Whilst I was thinking about the design of this, I was given an Adafruit Feather Huzzah 

This was ideal, as it had a Lipo PSU and charger built in, and plenty of IO, coupled with a 25mmx9mm LIPO battery it gives loads of power..

Plus If you use MicroPython you got the neopixel support.

Realising that the operator would be blindfolded, I wanted some feedback so they would know when the torch was used. After trying a solenoid, I found this had two problems. 1. It was power hungry. 2. It took up a load of space.  So I went back to a large’ish vibration motor (also to hand)

I had decided that the whole thing should fit in a tube no more than 40mm in diameter, so I laser cut some supports and hung the whole lot from two m3 threaded bars. After many attempts I finally got the acrylic into pieces that would support the electronics and battery and assembled the whole thing together. 


Of course, I’d forgotten the buttons. These needed to be at the front, but so the case could be removed they needed to connect at the back.

After a couple of attempts with internal wiring, that got cought up either putting it together or taking it apart. I eventually put the wires on the outside, covered the whole handle, wires and everything in leather and connected the buttons with a cable at the back.

The USB cable for power (and programming) currently exits out of the back, but is soon to be replaced with a micro socket.  There is also a small switch for the units power.

The next addition was a burst fire mode, you get 5 shots in quick succession, but it takes longer to recharge.

I also added an auto power off, if left for 60 seconds.

Circuit Diagram 

Download (SVG, 21KB)

Final Touches…

End plate with USB charging port and On off switch.

Unfortunately as I take the power for the motor, Neopixels and the main LED straight from the battery Powering down is a two stage process. First you press and hold both buttons. After a few seconds everything is turned off. Then you can switch off the uP. I do it this way as  I don’t have to switch everything on to charge it.

The finished Torch


import machine, neopixel, time, utime

np1 = neopixel.NeoPixel(machine.Pin(12), 8)
np2 = neopixel.NeoPixel(machine.Pin(13), 8)
LED5w = machine.Pin(14, machine.Pin.OUT)
B1 = machine.Pin(5, machine.Pin.IN, machine.Pin.PULL_UP)
B2 = machine.Pin(2, machine.Pin.IN, machine.Pin.PULL_UP)
vib = machine.Pin(4, machine.Pin.OUT)



def fire(fx):
   for x in range(0,fx,1):
      for a in range(8):
def charge(cx):
  for a in range(8):
def vibrate():


while(B1.value() or B2.value()):
  if not B1.value():
    if(not B1.value()): 
  if not B2.value():
    if(not B2.value()): 
  if ((utime.ticks_ms()-start) > OffTime*1000):
    for a in range(7,-1,-1):

for a in range(7,-1,-1):

Nottingham Gaussfest 2018

What a great day at Papplewick Pumping station. The change of venue caused some teething problems with space and I caused some problems with exhibitors names (no change there!) Over 140 visitors, three film crew’s on the day and 12 Exhibitors.


The pumping station were great in sorting out our rather strange needs and were over the moon about the attendance (they ran out of bacon in the cafe, apparently the indication of a good day). All proceeds from the day went directly to the Pumping station.

Photos from the day, If you, or your equipment is missing, please email me a picture/video. It was such a busy day I missed a lot of things.

Derek’s (my) Equipment

Sam’s Equipment

Tony/Leicester Hackspace

Alex’s Equipment

Dave’s Equipment

Jason’s Equipment

Roger’s Equipment

Chris’s Equipment

Chris with his Florescent tubes and small radio

Chris’ Battery powered Tesla coil

Andrews Equipment


After a number of valiant attempts and a few disasters. Earl unfortunately failed to get his coil working. This was a great shame as the travel and effort he put in was huge. I would have loved to see his coil in action again. I especially wanted to see his bottle cap bank in action.

Robert’s Jacobs ladder


Papplewick Pumping station

A superb venue, although a bit cold, mitigated by a superb on site Cafe…

Flashing Light Prize 2017 – 2

Flashing Light Prize 2017 second entry

So I had a better idea… and as far as I know there is no restrictions on entering twice.

This time, I needed some thing more impressive. I’d been tinkering with a demonstration of lighting a bulb with a single connection for a while, so I tied it in with that. Unfortunately the only (working) tesla coil that I have that has enough power (actually RMS current at the topload) is the Aetheriser. So that is the coil I had to use.

A quick test with a long filament lamp proved the idea workable, but the free connection got a bit warm (e.g. too hot to touch) so I added a brass ball protection to the free end

The large ball on the other end gives stability and stops the lamp from falling over.

The stills from the video.

and the last one of the failed cap end..


My other entry to Flashing Light Challenge 2017

Tales of a cheap Chinese laser cutter – External info Links

External Links that I have found useful.

Laser alignment guide (Just add Sharks but applicable to most lasers)

0xFred All sorts of good K40 tips

So I bought a cheap Chinese 40W CO2 Laser Cutter and it’s actually OK (Part 3)

Mikes Electric Stuff – Cheap Chinese Laser cutter – A really early K40 blog

40 Watt Chinese CO2 Laser Upgrade with RAMPS & Arudino

Legend of the Cheap Chinese Laser Cutter – Applied Absurdity

My experiences Tales of a Cheap Chinese Laser cutter – Pre-Checks

PIZero Tesla Coils at the RI Christmas Lectures

Earlier this month it was my great honor to be invited to demonstrate the PI zero tesla coils at the Royal institution Christmas lectures.

The Christmas lectures were a Christmas institution when I was growing up and they formed a great part of my education, especially the ones by Eric Lathwaite. This year is their 80th televised Christmas Lecture, I’m sure in that time it has inspired the lives of many many children to investigate science, and long may it continue to do so.

Behinds the scenes at the lectures was incredible, the organised chaos that was happening was untrue. There were 20+ experiments in the lecture (the first of three) and moving them in and out of the theater was a very well choreographed scientific dance.

I have every admiration to the RI and Windfall Films that produce it.

Walking in to the theater and standing where Faraday and not to forget, Tesla himself had lectured, I can’t explain the feeling. Oh, and the 350+ kids watching you… No Pressure…

The theater is incredible, it’s so much smaller than it looks on TV, add three cameras, a lecturer and 10+ support staff (dressed in black), it doesn’t leave much room for demonstrations that need a couple of meters exclusion zone for safety.

What will be featured on the lecture on Boxing day, not a clue, as is usual with any filming, its down to the final edit.

Even if I don’t make it on to the show, watch anyway well worth it for kids of all ages.

Behind the Ri Christmas Lectures- Show 01, 2016 Mark Parker – Standup Maths (warm up guy)

This Lecture is the first to go out BBC4 20:00 Boxing day 2016

The video is now available at



Details of the PiZero Tesla coils 

Talk for Derby Geekeasy 11-8-16

HV talk in the Furnace inn in derby for Derby Geekeasy @geekeasyderby

Thanks to the people at the Derby Geekeasy for a great night, plus a special thanks for the staff of the furnace inn for being very accommodating (and having excellent beer)

Videos (thanks to Glyn)

If you would like a HV or Tesla talk in the Nottingham, Derby or Leicester area, please contact me.
The Wimshurst Machine

Wimshurst – Pinpong ball particle accelerator

Wimshurst – Bottle motor

Part 2 – Tesla coils

Code to write to I2C YwRobot display from PI command

Compile with  gcc -o i2c_lcd i2c_lcd.c -l wiringPi

i2c_lcd -i  init display
i2c_lcd -c  clear display
i2c_lcd -1:2:3:4 “text”  print text to line 1:2:3:4

[code]]czoyNTpcIiNpbmNsdWRlICZsdDtzdGRsaWIuaCZndDtcIjt7WyYqJl19[[/code] [code]]czoyNzpcIiAjaW5jbHVkZSAmbHQ7c3RkYm9vbC5oJmd0O1wiO3tbJiomXX0=[[/code] [code]]czo2OTpcIiAjaW5jbHVkZSAmbHQ7c3RkaW8uaCZndDvCoMKgIC8qIFN0YW5kYXJkIGlucHV0L291dHB1dCBkZWZpbml0aW9ucyAqL1wie1smKiZdfTt7WyYqJl19[[/code] [code]]czo2MjpcIiAjaW5jbHVkZSAmbHQ7c3RyaW5nLmgmZ3Q7wqAgLyogU3RyaW5nIGZ1bmN0aW9uIGRlZmluaXRpb25zICovXCI7e1smKiZdfQ==[[/code] [code]]czo2OTpcIiAjaW5jbHVkZSAmbHQ7dW5pc3RkLmgmZ3Q7wqAgLyogVU5JWCBzdGFuZGFyZCBmdW5jdGlvbiBkZWZpbml0aW9ucyAqL1wie1smKiZdfTt7WyYqJl19[[/code] [code]]czo2MDpcIiAjaW5jbHVkZSAmbHQ7ZmNudGwuaCZndDvCoMKgIC8qIEZpbGUgY29udHJvbCBkZWZpbml0aW9ucyAqL1wiO3tbJiomXX0=[[/code] [code]]czo2MDpcIiAjaW5jbHVkZSAmbHQ7ZXJybm8uaCZndDvCoMKgIC8qIEVycm9yIG51bWJlciBkZWZpbml0aW9ucyAqL1wiO3tbJiomXX0=[[/code] [code]]czo2ODpcIiAjaW5jbHVkZSAmbHQ7dGVybWlvcy5oJmd0OyAvKiBQT1NJWCB0ZXJtaW5hbCBjb250cm9sIGRlZmluaXRpb25zICovXCI7e1smKiZdfQ==[[/code] [code]]czoyNDpcIiAjaW5jbHVkZSAmbHQ7dGltZS5oJmd0O1wiO3tbJiomXX0=[[/code] [code]]czozMTpcImNoYXIgKiBsb2NrZmlsZT1cImkyY19sY2QubG9ja1wiO1wiO3tbJiomXX0=[[/code] [code]]czoyMjpcIiBpbnQgaTJjX2FkZHJlc3M9MHgyNztcIjt7WyYqJl19[[/code] [code]]czo4OlwiIGludCBmZDtcIjt7WyYqJl19[[/code] [code]]czoyMTpcIiBib29sIGJhY2tsaWdodD10cnVlO1wiO3tbJiomXX0=[[/code] [code]]czoxNTpcIiBpbnQgbGFzdF9kYXRhO1wiO3tbJiomXX0=[[/code] [code]]czoyMDpcInZvaWQgaW5pdF9sY2Qodm9pZCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyNjpcIiB2b2lkIEkyQ1dyaXRlRGlyZWN0KGludCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyODpcIiB2b2lkIEkyQ1dyaXRlRGlyZWN0QmwoaW50KTtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiB2b2lkIGxjZF9zdHJvYmUodm9pZCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiB2b2lkIGxjZF93cml0ZShpbnQpO1wiO3tbJiomXX0=[[/code] [code]]czoyOTpcIiB2b2lkIGxjZF9wdXRzKGNoYXIgKiwgaW50ICk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMzpcIiB2b2lkIHRlc3Rfd3JpdGUodm9pZCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyNjpcIiB2b2lkIGxjZF93cml0ZV9jaGFyKGludCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMjpcIiB2b2lkIGxjZF9jbGVhcih2b2lkKTtcIjt7WyYqJl19[[/code] [code]]czoyNjpcIiB2b2lkIGxjZF9jdXJzb3JvZmYodm9pZCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMjpcIiB2b2lkIGNoZWNrbG9jayh2b2lkKTtcIjt7WyYqJl19[[/code] [code]]czoyMjpcIiB2b2lkIGNsZWFybG9jayh2b2lkKTtcIjt7WyYqJl19[[/code] [code]]czoyNDpcIiB2b2lkIEFsbExpbmVzKGNoYXIgKiApO1wiO3tbJiomXX0=[[/code] [code]]czozNDpcInZvaWQgbWFpbihpbnQgYXJnYywgY2hhciAqYXJndltdKXtcIjt7WyYqJl19[[/code] [code]]czoxNzpcIiB3aXJpbmdQaVNldHVwKCk7XCI7e1smKiZdfQ==[[/code] [code]]czo0ODpcIiBpZiAoZmFsc2U9PShmZD13aXJpbmdQaUkyQ1NldHVwKGkyY19hZGRyZXNzKSkpe1wiO3tbJiomXX0=[[/code] [code]]czo1OTpcIiBmcHJpbnRmKHN0ZGVycixcIkNhblwndCBvcGVuIGkyYyBvbiBwb3J0ICVpXFxuXCIsaTJjX2FkZHJlc3MpO1wiO3tbJiomXX0=[[/code] [code]]czo4OlwiZXhpdCgxKTtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoxMzpcImlmIChhcmdjPT0xKXtcIjt7WyYqJl19[[/code] [code]]czoyMDpcIiBwcmludGYoXCJVc2FnZTpcXG5cIik7XCI7e1smKiZdfQ==[[/code] [code]]czozOTpcIiBwcmludGYoXCJpMmNfbGNkIC1pwqAgaW5pdCBkaXNwbGF5XFxuXCIpO1wiO3tbJiomXX0=[[/code] [code]]czo0MDpcIiBwcmludGYoXCJpMmNfbGNkIC1jwqAgY2xlYXIgZGlzcGxheVxcblwiKTtcIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBwcmludGYoXCJpMmNfbGNkIC0xOjI6Mzo0IFxcXCJ0ZXh0XFxcIsKgIHByaW50IHRleHQgdG8gbGluZSAxOjI6Mzo0XFxuXCIpO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBwcmludGYoXCJcXG5cIik7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2OlwiaW50IGk7XCI7e1smKiZdfQ==[[/code] [code]]czo2NzpcIiBmb3IgKGkgPSAxOyBpICZsdDsgYXJnYzsgaSsrKcKgIC8qIFNraXAgYXJndlswXSAocHJvZ3JhbSBuYW1lKS4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLWlcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMjpcIiBpbml0X2xjZCgpO1wiO3tbJiomXX0=[[/code] [code]]czoxNzpcIiBsY2RfY3Vyc29yb2ZmKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLTFcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiBsY2RfcHV0cyhhcmd2W2krMV0sMSk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLTJcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiBsY2RfcHV0cyhhcmd2W2krMV0sMik7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLTNcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiBsY2RfcHV0cyhhcmd2W2krMV0sMyk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLTRcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiBsY2RfcHV0cyhhcmd2W2krMV0sNCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLWNcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBsY2RfY2xlYXIoKTtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo2ODpcIiBpZiAoc3RyY21wKGFyZ3ZbaV0sIFwiLWZcIikgPT0gMCnCoCAvKiBQcm9jZXNzIG9wdGlvbmFsIGFyZ3VtZW50cy4gKi9cIjt7WyYqJl19[[/code] [code]]czoyOlwiIHtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBjaGVja2xvY2soKTtcIjt7WyYqJl19[[/code] [code]]czoyMTpcIiBBbGxMaW5lcyhhcmd2W2krMV0pO1wiO3tbJiomXX0=[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoxOlwifVwiO3tbJiomXX0=[[/code] [code]]czoxMjpcImNsZWFybG9jaygpO1wiO3tbJiomXX0=[[/code] [code]]czoxODpcIi8vwqDCoCBpbml0X2xjZCgpO1wiO3tbJiomXX0=[[/code] [code]]czoyMDpcIiAvL8KgwqAgbGNkX2NsZWFyKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiAvL8KgwqAgdGVzdF93cml0ZSgpO1wiO3tbJiomXX0=[[/code] [code]]czozNjpcIiAvL8KgwqDCoCBsY2RfcHV0cyhcInRlc3Qgc3RyaW5nXCIsMyk7XCI7e1smKiZdfQ==[[/code] [code]]czozNDpcIiAvL8KgwqDCoCBsY2RfcHV0cyhcIkxhc3QgbGluZVwiLDQpO1wiO3tbJiomXX0=[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyMTpcInZvaWQgY2hlY2tsb2NrKHZvaWQpe1wiO3tbJiomXX0=[[/code] [code]]czozOTpcIiBpZiggYWNjZXNzKCBsb2NrZmlsZSwgRl9PSyApICE9IC0xICkge1wiO3tbJiomXX0=[[/code] [code]]czoyNTpcIiBwcmludGYoXCJMb2NrIEV4aXN0c1xcblwiKTtcIjt7WyYqJl19[[/code] [code]]czo1NTpcIiB3aGlsZShhY2Nlc3MoIGxvY2tmaWxlLCBGX09LICkgIT0gLTEgKXt1c2xlZXAoMTAwMDApO31cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czozNTpcIiBGSUxFICpmcCA9IGZvcGVuKGxvY2tmaWxlLCBcImFiK1wiKTtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyMTpcInZvaWQgY2xlYXJsb2NrKHZvaWQpe1wiO3tbJiomXX0=[[/code] [code]]czozOTpcIiBpZiggYWNjZXNzKCBsb2NrZmlsZSwgRl9PSyApICE9IC0xICkge1wiO3tbJiomXX0=[[/code] [code]]czoxODpcIiB1bmxpbmsobG9ja2ZpbGUpO1wiO3tbJiomXX0=[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czozMTpcInZvaWQgSTJDV3JpdGVEaXJlY3REKGludCBkYXRhKXtcIjt7WyYqJl19[[/code] [code]]czoyMjpcIiBkYXRhPWRhdGEgJmFtcDsgMHhGRjtcIjt7WyYqJl19[[/code] [code]]czoyMjpcIiBJMkNXcml0ZURpcmVjdChkYXRhKTtcIjt7WyYqJl19[[/code] [code]]czoxNjpcIiBsYXN0X2RhdGE9ZGF0YTtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czozMDpcInZvaWQgSTJDV3JpdGVEaXJlY3QoaW50IGRhdGEpe1wiO3tbJiomXX0=[[/code] [code]]czoyMjpcIiBkYXRhPWRhdGEgJmFtcDsgMHhGRjtcIjt7WyYqJl19[[/code] [code]]czoxNjpcIiBpZiAoYmFja2xpZ2h0KXtcIjt7WyYqJl19[[/code] [code]]czozNDpcIiB3aXJpbmdQaUkyQ1dyaXRlKGZkLGRhdGEgfCAweDA4KTtcIjt7WyYqJl19[[/code] [code]]czo3OlwiIH1lbHNle1wiO3tbJiomXX0=[[/code] [code]]czoyNzpcIiB3aXJpbmdQaUkyQ1dyaXRlKGZkLGRhdGEpO1wiO3tbJiomXX0=[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyMjpcInZvaWQgbGNkX3N0cm9iZSh2b2lkKXtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiB1c2xlZXAoNDAwKTtcIjt7WyYqJl19[[/code] [code]]czozNjpcIiBJMkNXcml0ZURpcmVjdCgobGFzdF9kYXRhIHwgMHgwNCkpO1wiO3tbJiomXX0=[[/code] [code]]czoxMzpcIiB1c2xlZXAoNDAwKTtcIjt7WyYqJl19[[/code] [code]]czozMDpcIiBJMkNXcml0ZURpcmVjdCgobGFzdF9kYXRhICkpO1wiO3tbJiomXX0=[[/code] [code]]czoyMDpcIiAvL8KgwqAgdXNsZWVwKDQwMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyNTpcInZvaWQgbGNkX3dyaXRlKGludCBkYXRhKXtcIjt7WyYqJl19[[/code] [code]]czo0NTpcIiBJMkNXcml0ZURpcmVjdEQoKGRhdGEgJmd0OyZndDsgNCkmbHQ7Jmx0OzQpO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czo0NTpcIiBJMkNXcml0ZURpcmVjdEQoKGRhdGEgJmFtcDsgMHgwRikmbHQ7Jmx0OzQpO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czozMDpcInZvaWQgbGNkX3dyaXRlX2NoYXIoaW50IGRhdGEpe1wiO3tbJiomXX0=[[/code] [code]]czo1NDpcIiBJMkNXcml0ZURpcmVjdEQoKChkYXRhICZndDsmZ3Q7IDQpJmx0OyZsdDs0KSB8IDB4MDEpO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czo1NDpcIiBJMkNXcml0ZURpcmVjdEQoKChkYXRhICZhbXA7IDB4MEYpJmx0OyZsdDs0KSB8IDB4MDEpO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoxODpcInZvaWQgdGVzdF93cml0ZSgpe1wiO3tbJiomXX0=[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHhDMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiBsY2Rfd3JpdGVfY2hhcihcJ1RcJyk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiBsY2Rfd3JpdGVfY2hhcihcJ0VcJyk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiBsY2Rfd3JpdGVfY2hhcihcJ1NcJyk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMTpcIiBsY2Rfd3JpdGVfY2hhcihcJ1RcJyk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyMDpcInZvaWQgaW5pdF9sY2Qodm9pZCl7XCI7e1smKiZdfQ==[[/code] [code]]czoyNDpcIiAvKsKgwqAgUG9ydCBkZWZpbml0aW9uc1wiO3tbJiomXX0=[[/code] [code]]czozOTpcIiBhZGRyLCBibCxzdHJvYmUscncscnMswqDCoCBkNCxkNSxkNixkN1wiO3tbJiomXX0=[[/code] [code]]czo0MjpcIiAweDI3LCAzLCAywqDCoMKgwqAgLCAxLCAwLMKgwqAgNCwgNSwgNiwgN1wiO3tbJiomXX0=[[/code] [code]]czozOlwiICovXCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiAvL3NldCA0IGJpdCBtb2RlXCI7e1smKiZdfQ==[[/code] [code]]czozMTpcIiBJMkNXcml0ZURpcmVjdEQoMHgzMCk7IC8vd3JpdGVcIjt7WyYqJl19[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiB1c2xlZXAoNTAwMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiB1c2xlZXAoNTAwMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiB1c2xlZXAoNTAwMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoyMzpcIiBJMkNXcml0ZURpcmVjdEQoMHgyMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiBsY2Rfc3Ryb2JlKCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNDpcIiB1c2xlZXAoNTAwMCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNjpcImxjZF93cml0ZSgweDI4KTtcIjt7WyYqJl19[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHgwOCk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHgwMSk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHgwNik7XCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHgwQyk7XCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiBsY2Rfd3JpdGUoMHgwRik7XCI7e1smKiZdfQ==[[/code] [code]]czoxOlwifVwiO3tbJiomXX0=[[/code] [code]]czoyMjpcIi8vIHB1dCBzdHJpbmcgZnVuY3Rpb25cIjt7WyYqJl19[[/code] [code]]czo0MjpcIiB2b2lkIGxjZF9wdXRzKGNoYXIgKiBzdHJpbmdpbiwgaW50IGxpbmUpe1wiO3tbJiomXX0=[[/code] [code]]czozNDpcIiBpZiAobGluZSA9PSAxKXtsY2Rfd3JpdGUoMHg4MCk7IH1cIjt7WyYqJl19[[/code] [code]]czozMzpcIiBpZiAobGluZSA9PSAyKXtsY2Rfd3JpdGUoMHhDMCk7fVwiO3tbJiomXX0=[[/code] [code]]czozMzpcIiBpZiAobGluZSA9PSAzKXtsY2Rfd3JpdGUoMHg5NCk7fVwiO3tbJiomXX0=[[/code] [code]]czozMzpcIiBpZiAobGluZSA9PSA0KXtsY2Rfd3JpdGUoMHhENCk7fVwiO3tbJiomXX0=[[/code] [code]]czoxNjpcImNoYXIgYnVmZmVyWzIyXTtcIjt7WyYqJl19[[/code] [code]]czo5OlwiIGludCBhPTA7XCI7e1smKiZdfQ==[[/code] [code]]czozNzpcIiBmb3IoYT0wO2EmbHQ7MjA7YSsrKXtidWZmZXJbYV09XCcgXCc7fVwiO3tbJiomXX0=[[/code] [code]]czo0OlwiYT0wO1wiO3tbJiomXX0=[[/code] [code]]czoxNDpcIiBib29sIG9rPXRydWU7XCI7e1smKiZdfQ==[[/code] [code]]czoxMTpcIiB3aGlsZShvayl7XCI7e1smKiZdfQ==[[/code] [code]]czoyMDpcIiBpZihzdHJpbmdpblthXSE9MCl7XCI7e1smKiZdfQ==[[/code] [code]]czoyMzpcIiBidWZmZXJbYV09c3RyaW5naW5bYV07XCI7e1smKiZdfQ==[[/code] [code]]czo1OlwiIGErKztcIjt7WyYqJl19[[/code] [code]]czoyNDpcIiBpZiAoYSZndDsxOSl7b2s9ZmFsc2U7fVwiO3tbJiomXX0=[[/code] [code]]czo3OlwiIH1lbHNle1wiO3tbJiomXX0=[[/code] [code]]czoxMDpcIiBvaz1mYWxzZTtcIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBidWZmZXJbYV09MDtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoxMzpcIiBidWZmZXJbYV09MDtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo0MjpcIi8vwqAgcHJpbnRmKFwiQnVmZmVyICVpOiVzXFxuXCIsbGluZSxidWZmZXIpO1wiO3tbJiomXX0=[[/code] [code]]czoyNzpcIi8vwqAgZm9yIChhPTA7YSZsdDsyMDthKyspe1wiO3tbJiomXX0=[[/code] [code]]czozNjpcIiAvL8KgwqDCoCBsY2Rfd3JpdGVfY2hhcihidWZmZXJbYV0pO1wiO3tbJiomXX0=[[/code] [code]]czo3OlwiIC8vwqAgfVwiO3tbJiomXX0=[[/code] [code]]czo1OlwiIGE9MDtcIjt7WyYqJl19[[/code] [code]]czo0MTpcIiB3aGlsZSgoYSZsdDsyMCkgJmFtcDsmYW1wOyAoYnVmZmVyW2FdKSl7XCI7e1smKiZdfQ==[[/code] [code]]czoyOTpcIiBsY2Rfd3JpdGVfY2hhcihidWZmZXJbYSsrXSk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyODpcIi8vIGNsZWFyIGxjZCBhbmQgc2V0IHRvIGhvbWVcIjt7WyYqJl19[[/code] [code]]czoyMjpcIiB2b2lkIGxjZF9jbGVhcih2b2lkKXtcIjt7WyYqJl19[[/code] [code]]czoxNjpcIiBsY2Rfd3JpdGUoMHgxKTtcIjt7WyYqJl19[[/code] [code]]czoxNjpcIiBsY2Rfd3JpdGUoMHgyKTtcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyNTpcInZvaWQgbGNkX2N1cnNvcm9mZih2b2lkKXtcIjt7WyYqJl19[[/code] [code]]czo0MDpcIiBsY2Rfd3JpdGUoMHgwYyk7IC8vY3Vyc29yIGFuZCBibGluayBvZmZcIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czozMTpcInZvaWQgQWxsTGluZXMoY2hhciAqIGZpbGVuYW1lKXtcIjt7WyYqJl19[[/code] [code]]czoxMDpcIkZJTEUgKiBmcDtcIjt7WyYqJl19[[/code] [code]]czoyMDpcIiBjaGFyICogbGluZSA9IE5VTEw7XCI7e1smKiZdfQ==[[/code] [code]]czoxNjpcIiBzaXplX3QgbGVuID0gMDtcIjt7WyYqJl19[[/code] [code]]czoxNDpcIiBzc2l6ZV90IHJlYWQ7XCI7e1smKiZdfQ==[[/code] [code]]czoyNjpcImZwID0gZm9wZW4oZmlsZW5hbWUsIFwiclwiKTtcIjt7WyYqJl19[[/code] [code]]czoxODpcIiBpZiAoZnAgPT0gTlVMTCkge1wiO3tbJiomXX0=[[/code] [code]]czo0MzpcIiBmcHJpbnRmKHN0ZGVycixcIkNhbnQgb3BlbSAlc1xcblwiLGZpbGVuYW1lKTtcIjt7WyYqJl19[[/code] [code]]czoyMDpcIiBleGl0KEVYSVRfRkFJTFVSRSk7XCI7e1smKiZdfQ==[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo4OlwiaW50IGw9MDtcIjt7WyYqJl19[[/code] [code]]czo3ODpcIiB3aGlsZSAoKChyZWFkID0gZ2V0bGluZSgmYW1wO2xpbmUsICZhbXA7bGVuLCBmcCkpICE9IC0xKSAmYW1wOyZhbXA7IGx7WyYqJl19Jmx0OzQpIHtcIjt7WyYqJl19[[/code] [code]]czo4OlwiaW50IGE9MDtcIjt7WyYqJl19[[/code] [code]]czoyMzpcIiBmb3IoYT0wO2EmbHQ7bGVuO2ErKyl7XCI7e1smKiZdfQ==[[/code] [code]]czoxNzpcIiBpZiAobGluZVthXSE9MCl7XCI7e1smKiZdfQ==[[/code] [code]]czozMjpcIiBpZiAobGluZVthXSZsdDtcJyBcJyl7bGluZVthXT0wO31cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czo0OlwibCsrO1wiO3tbJiomXX0=[[/code] [code]]czoxODpcIiBsY2RfcHV0cyhsaW5lLGwpO1wiO3tbJiomXX0=[[/code] [code]]czoyOlwiIH1cIjt7WyYqJl19[[/code] [code]]czoxOlwifVwiO3tbJiomXX0=[[/code]




Morse code test oscillator

Simple Morse code test oscillator for Morse practice – A Simple (& cheap) soldering project


I designed this for a Scout group as a simple soldering project Electronics Badge and as part of the Communication Badge.

With care the parts can be sourced for under £2.50 each.

20160427_172802 20160427_172810 20160427_172820 20160427_172754

The boards can be ordered from OSH Park and cost £2.20 for 3
Order from OSH Park





1 x 3mm Led
1 x 1K(or 300R)
1 x Sounder (10 mm pitch) max diameter of 12mm
1 x CR2032 vertical battery holder
1 x CR2032/LR2032 battery
1 x Push button 5mm pitch x 7.5mm pitch

Some Electronic expertise needed, and of course a good soldering teacher.

This project uses Lithium Button batteries, please note the warnings here – Do Not short out the batteries, and Do Not swallow them.

Morse Code

Morse Code decoding “tree”



If you wire two boards together (wire the two sounders together with a long bell-wire cable, be careful to get them both the same way around) you can make a telegraph system with a button and sounder at each end. Then you can practice sending and receiving for real….


Construction details are here



Lichtenburg figure test

Test of transformer choice and wood type for reliable Lichtenberg figures.

Obit – 20Kv 20mA

Both pieces of wood lightly soaked in water (only) just before test.

wood – 4mm MDF

20160420_190448 20160420_190445

Wood length 18″ – each pattern ~6″ across.


Course grained 3 ply

20160420_192526 20160420_192530

Burns only continued in line with the grain. Test abandoned.