Introduced in the 1960s, Secticon clocks are celebrated as revolutionary milestones in both avant-garde product design and electronic horology. Encased in sculptural, organic housings designed by Angelo Mangiarotti, these space-age timepieces are driven by Swiss Portescap constant-force electro-mechanical calibres. Powered by a single low-voltage battery, the Portescap mechanism utilises a transistorised motor circuit to rewind a constant-force escapement, maintaining a classical hairspring balance wheel.
At Harris Horology, our specialised background means we approach these pioneering electro-mechanical pieces with a deep commitment to historical preservation. Operating from our fully equipped London studio, we handle every level of Secticon or Portescap care. We draw directly on our museum conservation and practical repair experience. This ensures your clock retains its absolute historic integrity and mid-century aesthetic charm while returning to flawless, reliable timekeeping health.
For more general clock repair information click here.
These unique precision movements were used by a wide range of high-end manufacturers including Jaeger Lecoultre, Garrard and Wempe. Additionally, many watch brands such as Omega and Universal Geneve utilised them for advertising clocks in window displays where their long battery life and incredible accuracy would guarantee a good representation of the brand. Our workshop combines all the skills and expertise to work on these unique precision movements, with our watch repair, clock repair and specific electric clock knowledge being utilised.
For a deep dive into what makes these clocks special and a photographic teardown take a look at our blog post on these movements here.
Read examples of our other clock repairs on our blog here.
Many high-street jewellers or modern clock centres will declare a dead Secticon clock "unfixable" due to obsolete parts, aggressively pushing to rip out the original movement and replace it with a cheap battery quartz module. We find this practice unacceptable. Ruining a rare Swiss Portescap movement completely destroys the historical and financial value of a Secticon clock. Our workshop operates under a strict preservation philosophy: we repair, re-solder, and rebuild original electro-mechanical assemblies, hand-fabricating mechanical components from raw steel or brass directly at our bench when spares are completely unavailable. If you’ve previously been told that nothing can be done about your Portescap clock, get in touch with us as repair is almost always possible.
Harris Horology is only open by appointment - please initially contact us for an initial discussion about your watch and make an appointment here to bring your clock in to our Brixton studio.
Contact us here for a repair quote.
More about repairs
Preserving Design Icons
Secticon clocks are highly valued for their radical, fluid casework materials—ranging from molded melamine and lacquered plastics to heavy structural ceramics. Over the decades, exposure to sunlight and improper handling can leave these casings brittle, cracked, or dull. We specialize in stabilizing historic mid-century shells, removing surface oxidization, and repairing hairline fractures while carefully preserving the original factory colorways and design geometry.
Clocks worth repairing
Whether you own a classic desktop Secticon teardrop, a rare wall-mounted variation, or an industrial Portescap master-clock assembly, we handle all models with absolute care. Our workshop maintains an extensive international network of new-old-stock components and period-correct replacement transistors, ensuring that any component introduced to your clock matches its original technical era.
Secticon Repairs Near Me
When dealing with rare Swiss electro-mechanical architecture, sending your clock to the nearest local shop is a major gamble. We are deeply committed to premium horological standards and back all full mechanical restorations with a comprehensive 24-month workshop warranty. Our Brixton studio is proudly trusted by mid-century design galleries, private collectors, and museum curators across the UK.
Contact us here for a repair quote.
Reviews
Don’t just take our word for it, trust our fantastic clients. These quotes are taken from our Google reviews:
“It is now a while since I collected my Barwise bracket clock from Harris Horology after a complete clean and refurbishment. In this time, the clock has run faultlessly, keeping accurate time (unprecedented till now). I can only praise the meticulous work done to achieve this, giving a clock made 200 years ago a new lease of life.”
“James repaired a very old and extremely precious wall clock, an heirloom that came with a huge amount of emotional weight, in addition to its financial value. He made a first rate job, his communication and pricing was clear and very reasonable, and he was flexible with regard to the fact I don’t drive. He was also kind and personable to deal with, and I intend to use him in the future. I wholeheartedly recommend him - thank you for a wonderful job.”
“I have taken a selection of watches and clocks for repair since I heard of James Harris from a friend. The quality of service is superb. James is a dedicated and immensely skilful craftsman, and the whole operation at Cornerstone Studios is immaculately organised and executed. Above all, he and his staff clearly care immensely about his work and the results are well worth the cost - especially in the restoration of old and valued family pieces. Such expertise, as well as the personal involvement, is rare to find these days, and I recommend Harris Horology most strongly.”
“I recently sent an old French clock here to be repaired. It has been in my wife’s family for a long time and no one can remember it working. James took the clock, repaired, cleaned and tested it. It was a professional and fantastic job and now keeps excellent time. Just the trip to the workshop is an interesting and rewarding experience in itself as the pace is exactly as you would imagine a clock repair shop to be. I fully recommend this service by people who care and really know what they are doing.”
My Secticon clock has fresh batteries installed, but the balance wheel stops after a short time. What is causing this?
When a battery-powered Portescap movement stalls despite a fresh power source, the issue typically stems from one of three factors: hardened or dried oil inside the mechanical wheel pivots, occasionally an electronics issue, or very commonly the unique rubber drive wheel has degraded and is no longer functional. As part of a full service, the entire movement is stripped down to its components to allow thorough and meticulous cleaning to remove old oils and dirt. After much R&D we have developed our own replacements for the rubber detent wheel, which often is the reason these movements have been condemned as ‘unrepairable’. Now we can fit these while servicing a Secticon or Portescap clock, bringing these incredible movements back to life. We do not sell the wheels on their own.
What type of batteries should be used in a vintage Secticon clock to prevent damage?
Portescap movements were engineered around standard 1.5v cells. The absolute rule for mid-century electro-mechanical clocks is to never leave a battery inside a non-running movement. Old batteries leak highly corrosive acidic fluids that travel up the terminal leads and across any other surfaces, eating away the delicate copper circuits or damaging the delicate mechanical components. Luckily, a small feature of Portescap movements is their clear plastic dust cover. This has thankfully helped protect many clocks which would have otherwise been written off by damage from battery leakage.
Can a vintage Portescap movement be regulated to keep precise daily time like a modern watch?
Yes, exceptionally so. While they do not utilise quartz crystals, Portescap electro-mechanical movements feature highly refined balance wheels and hairspring assemblies that operate with a clever constant-force escapement. Because the pallets deliver an identical amount of energy to the balance wheel with every beat, these clocks are capable of outstanding daily accuracy and consistency that can only be achieved by some exceptional mechanical clocks. We calibrate and regulate these movements using modern electronic timing equipment at our bench with a goal of meeting the factory specifications of +/- 2 seconds per day.