About This Blog

My blog is a showcase and a platform for me to share my efforts and endeavours in electronics and related software. By documenting and cataloguing the projects I create, repairs I undertake, reviews and opinions I present, and making this all available I hope it will be at least interesting, useful and maybe even educational for others. As an (important) aside, I have chosen to use video extensively because I want to learn how to be succinct and talk *normally* when on camera – for some reason I seem to struggle to talk to a camera, I waffle, I say “Er” and “Um” far too many times, I don’t know how to leave gaps and I often say stupid or even wrong things, I generally feel a bit dumb when I am on video – doing this blog is my way of forcing myself to get over it – so apologies in advance if the videos are boring or not engaging, I am working on improving my video presentation skills.

Blog Disclaimer

Because this blog focuses on electronics you should know that I am not “qualified” in electronics or in software development. I have not had any formal education in either subject, what I know I have taught (or somehow know) myself, a fact that I am neither ashamed of – nor coy about. However, you should also know that the lack of formal qualification does not mean I do not take it seriously, I do – I have spent a lot of time learning to use, and a lot of money buying my test gear, machines and other paraphernalia that I use, I am IMHO competent and capable, safe and responsible so in that regard I am a professional engineer so I will do my very best to be accurate and factual with my content. I will of course not expect you to take my word for that, you can make your own judgement about my competence and capability if you do watch or read any of my content.

About Me

You have probably worked this out but just in case, my name is Gerry Sweeney. When I am not relaxing with my family and friends or doing my day job (see below), I love to find interesting ways of combining electronics and software to create new, novel or interesting things and I love to share what I learn with others. It’s true I am a geek – but I am also social, outgoing, I have a sense of humour, I am happy to speak about things in front of large audiences of people, I can hold a conversation about subjects that are not at all geeky. Fact is though, I like to understand how the world around me works and if I can, I like to try and improve on things that need improving. My own worst personal trait is probably my tenacious, often blind desire to do something simply because someone tells me “it can’t be done” – if I think it can be done, I will probably try to do it – I will often fail, and I will openly celebrate failure, but at least I will try.

I grew up in Willesden in London, UK. From a very young age (maybe as young as 7) I was messing with electrical stuff.  By the time I was in my early teens I was that go-to person to fix anything from TV’s, HiFi, watches, domestic appliances, cars, bikes, engines, house electrics, burglar alarms, telephones, CB and amateur radio, video game and slot machines and computers, basically if it was electrical or mechanical and I could take it apart and fix it – I did. I eventually got tired of being the “free community repair man” so I stopped fixing TV’s and turned my attention to a career instead – bizarrely and to the surprise of many that knew me – I did not take up a career in electronics.

By the time computers were becoming popular in the 80’s, its far to say that my understanding of electronics lead me to computing because there was an obvious connection, my first computer was a Sinclair ZX81, I was still at school, I was 15 and while my friends were typing programs into their own ZX81 from a listing in a computer magazine, I was soldering TTL chips into my ZX81 to make it program EPROM’s and wondering how that magical UCLA chip in there worked – no one really understood why I used to do that stuff and sadly, my home town not being a Silicon Valley hotspot, it was difficult to share experiences and network with like-minded people to learn more – I had to figure it out on my own.  I do have some great like-minded friends now and of course thanks to the power of the internet and youtube there are many people I don’t know with who I share this interest with.

This interest in electronics converges now with my software experience all manor of modern-day technology like energy, IoT, EV’s and many other technologies mix electronics with software.

My Career Biography Summary

  • Odd Jobs
  • Auto Electrician/Breakdown
  • Part Time DJ and Band Member
  • Home & Commercial Alarm and Security Systems Install and Servicing
  • Field Engineer, EPOS, Vending and others
  • Computer Field Service Engineer
  • Computer Network Engineer (Novell CNE, Microsoft MCP)
  • IT Contractor (IT projects, infrastructure, and support)
  • IT Manager (people, budgets)
  • Founder, CEO and CTO – Hornbill

About My Day Job

Aside from my family and close friends, the next most important activity in my life is my day job. In 1995 I founded a small B2B software company called Hornbill; I started that company with a friend, with no money, no staff and no work. My goal was to create a successful software company and I had global aspirations, I wanted to create IP and build a close nit team of professionals and experts to work with, I wanted to do that on my own terms which at the time meant no debt, no venture capital or external funding – in other words the company had to make money from day one, and keep on making money to keep the lights on. I have worked tirelessly from that day to this to make that happen – I still run and manage that company today, I am Founder/CEO/CTO and I take that responsibility very seriously, its hard work and has its challenges but I love doing it. Day to day I do everything from operational, strategy, product design and direction, customer escalations, staff management and team management. I drive our product and business strategy, and I have a great team of outstanding people who make it all work. We have about 650 customers globally including some very well known global companies; we invest heavily in R&D and remain financially strong under our own steam. In our most recent chapter, I have taken the company through a long and complicated journey of transitioning to a pure enterprise cloud company, our cloud infrastructure spans locations in Europe and North America and delivers our software as a service for our customers. I feel both proud and lucky to work with a team of some of the nicest, professional and most capable people in our industry, and as a team we get the privilege of working with some of the most outstanding, forward thinking, globally brand recognisable organisations.

If you got this far and are still awake, thank you for reading.


Copyright (C) Gerry Sweeney, All rights reserved.

This content is published under the Attribution-Noncommercial-Share Alike 3.0 Unported license.


  1. Hi, just recently came across this project, will it be available as a kit or maybe the PCB? also there does not appear to be much info about yourself Gerry, would like to learn more about what you do in your day to day job etc

    1. Hi Evan, I am not geared up to sell kits so probably not. However, if there is enough interest I was thinking about ordering a bunch of PCB’s and possibly some of the “expensive-in-one-off-or-shipping” components and making them available to anyone interested – just as a way of reducing the overall cost of the project for anyone (me included) that might want to build one. I will update the about page with more relevant personal information, my day job is quite distant to what I am doing here, my electronics knowledge really comes from way back before my working career took hold.

      1. Wow, Gerry, thanks for sharing your personal information. My interests in electronics as a lad is somewhat similar and later I also worked in IT. I guessed that you had some involvement in IT but to learn you created a successful global IT company is absolutely outstanding.

  2. 80’s teenager, electronics hobby, motorbikes, guitar, modified Sinclair ZX, “um, err” issues when video blogging………but that’s me I’m talking about, not you! I thought I was unique…..no more!

  3. Hi Gerry,

    great blog you have. I have been following for a long time.

    Just curious on your bare board PCBs, where do you get them from? is the manufacturer here in UK?


    1. Hi Sérgio,

      I use ITead Studio and custompcb.com both are in the far east, UK companies seem to be far too expensive. There is no perfect supplier though, best to try a few and find one you like/can work with.


  4. “I have not had any formal education in either subject, what I know I have taught (or somehow know) myself, a fact that I am neither ashamed of – nor coy about. ”

    My grandfather, a British Canadian, had nothing but a public school (government) education to his high school level. From there he self-studied and followed a fascination with electronics, working his way up, through the US depression, to service as radio officer aboard Liberty Ships during WWII and from there to industry. He ended his 45 year electronics career with the latter half at one company, Chase Shawmut, which is now Gould Shawmut, with scores of patents for industrial process and induction heating, much of which is likely still present in common household and industrial fuses today. I have always held his example as most admirable and, not just happenstance, our paths have sometimes met.

    He was, I now understand, a “didactic” learner. Someone who learned how to learn on his own, and did so quite effectively. Personal circumstances place me in the same category, yet minus so much accomplishment. Still, I recognize and appreciate the value of practical knowledge and experience gained over time. It is so unfortunate that experiential knowledge is increasingly downplayed; replaced with encapsulated plug-in self-learning, self-diagnosing systems (as one example). Unfortunate as these are ultimately headless horsemen.

    So all this to acknowledge and praise the advantage of practical, experiential education. In your case, having seen many of your video presentations, your engineering skills are top notch. You are methodical, careful, curious, and measure twice before cutting. Thanks for your efforts here on behalf of others. Well done indeed!

    1. HI Mark,

      Thats very kind of you to say, I wanted to make sure I did not claim any level of “professional expertise” so that I don’t mislead people. I appreciate the time you have taken to write the comment. Thank you


  5. Hi Gerry. I recently found your channel on YouTube while, like you, trying to self learn electronics. Your presentation skills are great, clear, factual and to the point. I like your style. I would like to know however; where do you get your PCBs made? As someone starting out I find it difficult to find a manufacturer who will make a batch of 10 boards or less when prototyping an idea. Do you ever make your own copper clad boards for example? I live in Ireland so perhaps I can use a company in the UK. I hope to do either electronic engineering or electrical engineering next year as mature student (25) and it would be nice to bring along some boards to show off at the interview, to give the impression of semi professionalism. Anyway I love your channel Gerry and keep the videos coming. Ps. Where are the first 7 power supply videos, they seem to be unlisted? Kind regards Jason aka SeaMonkey.

    1. Hi Jason,

      Thanks for the feedback, much appreciated. I get my boards made in China, I have yet to find a UK manufacturer that can offer anything like the price point or turn-around for low-volume prototype boards, in reality this type of work seems to be outsourced to china behind the scenes. Now while I will tell you who I use I want to caution you that service quality is *very* variable so you should take this as information rather than a personal recommendation – that being said, for boards only they are both pretty good but your communication with them has to be 100% clear and concise, what would appear common-sense often is not the case. For example, I have been ordering a lot of boards from one supplier, always in black. Then on one order, even after stating black numerous times I had shipped to me 100 green boards – not the end of the world but frustrating. In their defence they acknowledged the problem was at their end and they re-made the boards and shipped them to me at no cost, I was still lumbered with another lot of import duty and delays. Thats the sort of thing that can happen so expect that, but board quality is good, turn-around is generally good and actually they are nice people when you talk to them, in reality $80 for 6 boards is not exactly going to make them millions so the service in many ways is reflected in the price and I don;t think thats entirely unreasonable. Anyways, the two companies I have used are ITeadStudio and SeeedStudio – you can google both to find them. They both have on-line ordering capability and they are both reliable board makers and the quality of the boards are pretty good. Hope that helps.


  6. Hi Gerry,

    Thank you for doing this blog, which I found from “that Aussie blokes” blog. I love the fact that you spend time explaining things in detail.

    I work from home and like to have a Vblog on in the background (it either tat or “Loose Women”).

    In response to Jason aka SeaMonkey looking for small runs of 10 boards, I have started using Smart-Prototyping for my PCBs. They do 10 boards 5cm x 5cm delivered to the UK for less then 10 GBP.

    I use Eagle CAD for PCB design, and they have a Design Rules CAM module which you can download to make sure your Gerbers are correctly configured.

    I run a small company manufacturing control PCBs, and I order 10 PCBs for prototyping (which I may use if I have designed my circuit right !), otherwise I make mods and then order in 100’s.

    I rarely use a breadboard as I prefer the ease and time saving element of going straight to PCB (despite the 3 week delivery time).

    Another firm I have used is OSH park, where you get 3 PCBs for a similar price.

    Both companies offer a good quality product, to slightly higher specification than generally offered at the low cost end, in my view.

    My tips would be: Beware of manufacturers adding unrealistic shipping charges at the last moment and check your design out at mayhewlabs using their 3D gerber viewer before ordering.

    I am not associated with any of these companies, other than being a normal customer.


  7. Hello Gerry,
    i had watched a youtube video on your channel about dark side screen problem on imac.
    i have a mid 2010 imac and have a vertical line problem but this is a bit different. if i focus the screen, i see the very very thin lines ( just like moving pixels) i have never removed the imac screen.
    here is the photo:
    what is the problem? any idea?
    thank you

    1. Hi,
      I have not seen that problem before. If the pixel errors are always at the same physical position on the screen then it looks like problem on the actual panel. If the problem moves around the screen and is in different places then most likely a video card/memory problem.

  8. Hey Gerry, wondered if your going to continue with any electronics projects or other stuff
    anytime in the future!


    1. Hi Evan,

      Yes I will be fore sure. Unfortunately work commitments have taken over my life of late but I have a stack of projects to make videos around and will get around to them soon. Dont give up on me just yet 🙂


  9. Hi Gerry

    I just watched your 2013 youtube about Rubidium reference and also the Oscilloquartz OCXO.

    I have just bought a Navicom OCXO which I think is the same device (type 8663) and I too am impressed with its performance. I would like to chat more with you on this OCXO if you can spare the time.

    I have also built a 10 MHz freq reference by locking a PLL to the BBC Radio 4 Long Wave carrier and compared this to a UBlox NEO7 GPS module – both seem to be very good freq ref sources.



    Bill Hall
    C Eng, Fellow IET
    Wakefield, West Yorks

    1. Hi Bill,

      Thanks for watching. Nice idea PLL locking onto a broadcast signal, they generally have very good frequency references. Happy to talk about the OCXO if you like


  10. HI Gerry
    I am interest all concern about precise clock.
    My ability is not the same as you but I work hard
    to have a better understand.
    Recently I have read about your 10mhz ocxo clock
    built with max6198 and Isotemp ocxo.
    Do you thing it is possible to implant it on
    a standard nixie clock or cheap C51 led clock
    instead of the 32 000 hz crystal ?

    Charles (Quebec city)

    1. HI Charles,

      Yes sure it would be possible, you would need to implement a divider circuit to get you down to 1Hz so a few 74LS90’s or something like that which is quite common amongst DIY clock building projects. You will end up with one hell of an accurate timepiece doing that – you will never have to set the time again 🙂


  11. Hi Gerry,
    The ocxo I purchased over a month ago is performing 100% frequency remaining within a few cycles of my rb ref unit. It has made my hp53181a into a useable accurate counter. With the standard ref osc it would have been more use to calibrate it as a thermometer. I highly recomment your plug & play kit for upgrading hp 531xxx counters, also very professionaly designed & constructed .Thank you Gerry.
    Kind Regards,
    Paul Dixon,

    1. HI Paul,
      Thanks for the feedback, I appreciate it. I am really glad you like it. When I designed it, I was really just playing around, I was so disappointed with the stock oscillator in the HP counter I had I felt compelled to do something after I realised how poor the stock oscillator was, other than that counter is self is really nice and warranted some time and investigation. I never imagined I would sell as many of these as I have, there are many HP 531xx counters now sporting this upgrade module, I am delighted to have been able to create something that is of use to so many other hackers, makers and enthusiasts.

  12. Hello – I enjoyed your ‘dark side screen’ YouTube video – I wondered if you had any ideas on why an iMac 27inch would suddenly go to blank screen randomly – and the only way to get the screen back is to press the power button to ‘sleep’ then power button again to ‘wake’ Is this a sign that something is slowly going and needs replacing (such as video card) any ideas?

  13. jerry – just paid you for a HP5131 board – I hope you still have them in stock. Paypal details have my address.

    please confirm, wont order the parts until you do.

    many thanks

    Happy christmas and New year

  14. Hi Jerry,

    Great vids.

    Have you done a disassembly of the A1419 5K Retina screen unit? There are so many of them with cracked glass and intact LCDs, a repair video would be great.



    1. Hello John,

      I am afraid I have not, I know they are stuck using adhesive, so once you remove the screen you will need to buy an adhesive kit to put it back together.

  15. Hello Gerry,
    I just came across your blog and YouTube channel. I am interested in your programmable power supply. I am a DYI’er and am currently starting work on initial designs (peppered with probable failures I’m sure). Have you done any additional work on it?

    Looking forward to any help, advice and direction. Thank you in advance for your help.

    Best Regards,

  16. DEAR,

    2 x HP/Agilent 53131A-010/GS OCXO Option Bare PCB’s Rev 1F £23.50

      1. Hi Gerry,
        I’m a new subscriber to your blog, but have been following some of your projects over the past couple of years.
        Right now, I’m particularly interested in the HP 53131 OCXO project. Would you be willing to share the PCB design files? I’d like to add a couple more OCXO models to the board (for my own use). I seem to have collected more than a few different brands and models over the years, and would like to put them to use. Your board could easily be modified to my purpose.


  17. Dear Gerry,
    Got this far, still awake, but more correctly absolutely blown away by your story! Amazing the similarity/parallels amongst us geeky folk and how we came up thru the ranks over the years. Thank you for sharing and your videos. My order for your rev 1G – Agilent 53131A unit, just went in. Best regards from down under. Tony.

  18. Just came across your video about 27″ iMac 2011 left side of screen flickering or dark. great soldering job. I have repaired two, success. Just got same machine, broken display, bookshelf fell on it. Complete write-off. data on HDD was fine.
    question is, have you ever had the chance to completely eviscerate or disembowel the 27″ display?
    Requires COMPLETE disassembly, all of the layers inside of the display, just to get to the LED strip on bottom of display.
    I have some picts but did not make a video.

    Wife says I have to much time on my hands.
    I look forward to hearing from you.
    Thanks from beautiful, on fire, Northern California
    Bill Peart
    Chico Cal

    1. Hi Bill,
      I have not, I actually have a 27″ computer here with the exact same fault and my plan was to do that full screen teardown but never got around to it sadly 🙁

  19. Good morning Gerry, I’m Marco, I have a problem with M9712B30 500v 30A 300W, can you help me?
    A 14D201K varistor is mounted on the instrument input in position Y3 in parallel with the input, as the instrument goes up to 500v it appears to have been mounted incorrectly at the factory.
    While a 14D751K varistor is mounted in position Y1 which is connected between positive input and ground, is it possible that they were reversed at the time of assembly?
    if you have this tool can you check how yours was assembled?


  20. Hi Gerry, congratulations.
    I am perhaps your elder reader but like you, with a deep passion by electronics and a “former” workaholic.
    You are very descriptive and a good writer, a rare characteristic of “good” engineers.
    During my professional life all dedicated to technology, and inside the same company for 40 years I begin my career with the portuguese representative of HP caring about measuring instrumentation in very poor installations and reduced technical resources so after one year I was candidate for a job with Philips.
    Then I was luck finding a big mistake on the examination 10 points test sheet.
    Immediately admitted the mistake was reported to Philips International (NL), I was promoted and send to Netherlands to get a B.Sc.
    Today, 81 years old, living in Lisbon retired as director after some years as Area manager for MEA, I have pensions from Portugal and Netherlands, a family and two hobby rooms.
    Therefore I never was dedicated to other fields like my car engine or painting, overall I’m not the kind of energetic person although the many projects were I was evolved.
    Best regards and success
    Rui Figueiredo

  21. Hi Gerry, hope you’re doing well.

    I also found your blog via your YouTube content and “about” section. Echoing posts made by others, your descriptions of processes, circuits, modifications, et al are excellent, and it was fun watching your videos.

    Having spent a bit of time working in Avionics for the US government, I really appreciate your taste in equipment. During that time, I experienced many different makes and models of test equipment while setting up and using test stations for component level repairs and calibration. Much of what you use are favorites of mine, and I’ve been picking up some pieces for a home test bench too. Lately I’m refurbishing some old stereo amplifiers.

    I’m also professionally involved with software and broad technical architecture these days. Quite similar interests since the 80’s.

    Take care,

    1. Hi Mike,
      Thanks for the comments and feedback. Unfortunately my day job has been all-consuming over the last few years, I plan to get back to this blog and projects at some point.
      I too have been recently building a collection of vintage HiFi gear, just completed a full Pioneer SPEC system, RT-909, RT-707, SPEC-1, SPEC-4 and hoping to get a PLC-590. Never enough time for these things 🙂


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