About Me

Lets start with the basics. My name is John. I currently live in New Zealand.

I have a number of interests including photography (stereophotography included), computer programming, electronics, flying and model aircraft.

I develop software for a living.

Contact me by sending an email to .

Written by John in: |


  • Isaac Scott

    Hay im trying to find police frequincys in mount maunganui my radio has MHZ and KHZ would u be able to help me i see u have on ur site a lidt but i dont know if it is MHZ or KHz?

    Comment | 10 June 2009
  • Stumbled into your blog. Impressive. First, please respond to this so that I know I’ve succeeded in contacting you. Thanx.
    All the best.

    Comment | 6 August 2009
  • Debi Jacka

    Just found an amazing aerial shot of yours of Piha/Lion Rock. As a fundraiser the Piha SLSC are doing a calendar this year and I would really really love to include that photo as one of the “Month” shots. Wasnt sure how to get in contact and ask permission so hopefully this gets to you in time as we are putting what photos we have together but we have nothing like that aerial shot.Amazing.
    Tks Debi

    Comment | 30 August 2010
  • Hello John, thank you for nice article regarding TX20. Iam currentlu using it with my Atmel chip and getting readings nicely. My CRC error rate is around 2 %, is this reasonable value for TX20 data packets ??

    Comment | 3 August 2011
  • Damian

    Could you do a post on how the actual violet wand circuitry work with schematics explained. I have been searching the internet like crazy to no avail. Can’t find anyone else with hands on technological experience.

    Comment | 19 January 2012
  • George

    Hi John, I read your countdown hard hat article and love it. Could you please post a “how to” for the electronics and programming, I’d like to make a countdown timer with my arduino duemilanove. Thanks

    Comment | 25 January 2012
  • Hi John, Did you connected the Raspberry PI GPIO to the La Cross Sensors ?. any code ? . Thanks

    Comment | 12 October 2012
  • tom

    Any progress on your violet ray repair?

    Comment | 28 January 2013
  • John

    Hi John.
    Do you know if we can still get to hear the police in any part of Otago using the unbidden 93xlt analogue scanner.

    Comment | 4 March 2013
  • Olearius

    Hi John, unfortunately your Email-adress above did not work, so I contact you here.

    Have seen your cheap tally counter modified to a counter for machinery on
    and I am impressed.

    I also purchased a very small and cheap tally counter like this

    I wanna modify that tally counter in such a way that it will work with a piezo disc as knock sensor; one knock – one count.

    You know, when tipping or knocking on such a piezoelectric disc a voltage is generated like seen in that video:
    I wanna count these electric impulses caused by the knocks.

    The piezo disc don’t need to be housed in the casing of the tally counter; disc is located outside the housing but need to be connected with the board of the tally counter.

    I am not well gifted in electric things, so maybe I ask ask you: How would you realize such a knock counter?

    Could send you also some pics of the disassembled tally counter (in that email I don’t attach pics because I don’t know if my email will land in your spam folder).

    Thank’s in advance for your valued reply and kind regards.


    Comment | 2 October 2014
  • Alfie

    Greetings not sure if this went through the first time
    for ST John Ambulance nz

    Chief Complaints

    1 Abdominal Pain / Problem
    2 Allergies – Reactions to Stings / Bites etc
    3 Animal Bites / Attacks
    4 Assault / Sexual
    5 Back Pain Non – Traumatic / Non – Recent
    6 Breathing Problems
    7 Burns / Explosions
    8 Carbon Monoxide / Inhalation / Hazmat / CBRN
    9 Cardiac or Respiratory Arrest / Death
    10 Chest Pain
    11 Choking
    12 Convulsions / Seizures
    13 Diabetic Problems
    14 Drownings / Scuba Diving Accident
    15 Electrocution / Lighting
    16 Eye Problems / Injuries
    17 Falls
    18 Headache
    19 Heart Problem
    20 Heat / Cold Exposure
    21 Hemorrhage / Lacerations
    22 Machine Accident / Inaccessible Incident / Entrapments
    23 Over Dose / Poisoning ( Ingestion )
    24 Pregnancy / Child Birth / Miscarriage
    25 Suicide Attempt / Psychiatric
    26 Sick person
    27 Stab / Gun Shot Wound / Penetrating Trauma
    28 Stroke ( CVA )
    29 Traffic / Transportation Accident
    30 Traumatic Injuries
    31 Unconscious / Fainting ( Near )
    32 Unknown Problem ( Man Down )
    33 Inter – Facility Transfer / Palliative Care
    34 Automatic Crash Notification
    35 Health Care Practitioner Referral
    36 Flu Like Symptoms
    37 Inter – Facility Transfer / to Medially Trained Callers

    Comment | 14 June 2015
  • Nice blog John. Thanks for sharing. I chuckled when I saw Isaac Scott’s misspelling of “list” in the comment from 2009. T minus idiocy and counting. 😉

    Comment | 22 December 2016
  • Ian

    New Zealand Uniden BCD325P2-AU or BCD996P2 Owners

    Hi all. I’m thinking of buying either of the above. I would like to hear from anyone here in New Zealand, who has experince with these and wether they are suitable or not for the New Zealand Freqs Etc. I live in Christchurch. I have a Uniden and AOR, but would like to purchase a Digital Scanner. Are either of the above sitiutable and have you had any problems so far, or anything that might shine a light for my understanding Etc.
    There’s next to nothing (that I am aware of ) here in New Zealand to find out about these scanners and their suitability

    Thanks Ian

    Comment | 9 January 2017

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