Welcome to my website, where you'll find a selection of electronics and audio projects; sections devoted to Hi-Fi, including BBC, Rogers and ATC loudspeakers and old Musical Fidelity amplifiers; plus a guide to PIC programming; and a selection of DIY projects.

What's new?

Recent updates and latest news:

  • Kaiweets KM602

    Kaiweets KM602

    The multimeter that thinks it's a smartphone! It has a massive, high contrast colour display and a rechargable battery. It also includes a "smart" mode that automatically decides between voltage, resistance or continuity. Let's see how well it works...

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  • New ISP

    Latest News

    I have changed my ISP, so my old Force9 email addresses no longer work. I apologise to anyone who has recently tried to contact me using those addresses - please follow the "Contact Me" links to get in touch again.

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  • Budget Multimeters

    Budget Multimeters

    Not everyone can afford or justify expensive professional equipment in their hobby workshops, but while cheap multimeters are plentiful, are they any good? What are the potential problems with cheap multimeters? Which ones should you consider?

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  • Time Electronics 1030 Micro Cal

    Time Electronics 1030 Micro Cal

    This unit is a precision hand-held voltage and current source that is incredibly neat and compact, and is still hand-made in the UK after more than 25 years of production. I present a review, tear-down, technical investigation, and restoration. Enjoy!

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  • AD584 Voltage References

    AD584 Voltage References

    Curious about those cheap voltage references that are all over eBay, I ordered up a batch for investigation. Measurements and full schematics are included as part of the reviews.

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  • Statistical DVM Reference

    Statistical DVM Reference

    A precision voltage source is a useful addition to an electronics workshop. This simple design uses a "statistical reference" and offers 10 output voltages with significantly better than 0.1% accuracy. Output protection and a low-battery indicator is included.

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  • Trialling a new contact mechanism - Update

    Latest News

    Things seem to be working reasonably well. I have tidied up the code, and added some JavaScript to validate the form interactively before it is submitted (it's also checked on the server because some people disable JavaScript). I've also opened up the Guestbook...

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  • Trialling a new contact mechanism

    Latest News

    For many months now, visitors have been unable to get in touch via the contact form. This is because I was using a simple script provided by my ISP, but they took it down because of security concerns. I'm experimenting with an alternative - let's see how it goes...

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  • Radiometer SMG40


    This is a pretty obscure bit of vintage test gear that is used for setting up stereo radio receivers. This article includes a brief look at the basics of FM stereo broadcasting, a good look inside the unit, and details of the repair.

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  • Transistors in Vintage Radios

    Vintage transistors

    An overview of the transistor types that were commonly fitted to vintage radios that were encountered on the UK market, including details of failure modes and possible fixes and substitutions.

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  • Replacing Volume Controls in Hacker Radios

    Replacing Hacker Volume Controls

    What to do when switch cleaner isn't able to provide a permanent cure - a guide to restoring or replacing worn volume controls in Hacker radios. Of course, the advice applies to many other types of vintage electronics.

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  • Mains Distribution Unit

    Mains Distribution Unit

    A simple project that started out as an investigation into cheap mains voltage/current modules. I incorporated a modified one into a mains distribution panel that is for "equipment under test", complete with monitoring outputs.

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  • Active Speaker

    Active Speaker

    Updated: I recently revisited this project, and spent quite a bit of time taking measurements of the performance. As a result, a different (and available) drive unit has been fitted, along with a high-pass filter switch...

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  • Stirling Broadcast SB-88

        Broadcast SB-88

    Loudspeaker review: the SB-88 from Stirling Broadcast is a brand new two-way loudspeaker designed by Derek Hughes.

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  • New Website Home!

    Latest News

    This website has a new permanent home - please update your bookmarks!

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  • BBC and Rogers Loudspeakers

    Rogers and BBC loudspeakers

    This section has had a lot of updates in light of research and submissions from visitors. The complicated story behind the LS3/6, Spendor BC1 and the Rogers Export Monitor is clarified, and details of several other BBC and Rogers speakers have been added.

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  • Musical Fidelity A1

    Musical Fidelity A1

    This section has been subject to several minor updates and corrections, and there are finally some details of the B1 on the "Other Models" page. I'm also hoping to expand the information about the B200 in the very near future.

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