I did post this further up the thread... "All of the contacts are made of 10% iridium and 90% platinum. The hipp toggle contacts pass between 400-500mA for the pendulum drive coil. Although running a

The contacts in the PO 36 were designed to 'wipe'. That is, that they continued to travel after contacting which led one to wipe over the other thus removing any oxide build up. I am not sure of the c

The GPO used a 200 ohm resistor in series with a 1 micro farad capacitor across the contacts on later type 36 clocks with simple make contacts. The earlier types with make before break contacts had a

I have an old 'tennis racket fly zapper' which broke. I stripped out the electrics and just wired the battery in series with the push button and popped a couple of fly leads on. works very well. With

The one I had in the late nineties had a gear wheel with loads of angled projections on and this was driven by a tiny tuning fork attached to a coil. From memory the fork vibrated and these vibrations

It could be that the hands are unbalanced, the balancing being done on the minute gear wheel as some older gent's clocks are. This would mean that after removal of the hands, the minute wheel would th

Fashions do come and go and so this £645 repurposed clock could well be worth £0 and a trip to the recycle centre in 10-15 years time. My main peeve is the sheer number of system clocks which have bee

It's still on ebay. I would be interested to know exactly what has been 'fully restored'? The dial is screwed, the case is screwed, the hands that should be the most protected look like they went 5 ro

Didn't work in my country, but I found another version which worked for me, YAY!... As to number 1 below, I can fix it not being viewable to some countries by posting this link instead. https://www.da

(Part 2) I knocked this up. Currently the Mark III version, it has proved to be invaluable. It's a PDF laid out in the GPO engineering instructions format as is the rest of the clock site which it wil

Very handy for testing and running pulse clocks. (video) https://youtu.be/LjBVoOipISY

Hi folks Following on from an earlier post which had a question about a stand for clocks, I finally got off my bum and made one that I have been thinking about for some time. Although designed for GPO

If the slave mechs are lubricated, then I can only think that the oil thickens os it gets colder. Sorry, my only guess at this. Simon GPO Clocks

Just enjoying lockdown by restoring an old GPO clock relay unit. I need to take a little care as apparently, GPOtelephones@... cloth cables were doped with arsenic to stop rats chewing them!

These clocks are pretty good at working. Like GPO stuff, very rarely it there something wrong with it. Usually, any damage is limited to bent bits that can be re-adjusted. Great hobby! Simon GPO Clock

Hi Jim, the speaking clock is a TIM2016 Unit that is fed into a MW transmitter. I just turn the radio on for time checks and thought it would be neat for the video soundtrack. I don’t have the TIM uni

It would have helped if I had mentioned what the batteries are running, LOL! Here is a quick vid from this morning. https://youtu.be/6hlWNCP8CXg Simon GPO Clocks

My clock system has two 90 Ah lead acid batteries. The very first thing I did was to put inline fuses on the battery connectors. I also do the same for the isolation transformer if testing an old piec

Sounds like it’s all going in the right direction. Simon GPO Clocks

Hi John, The Synchronome ½ minutes clocks made for the GPO only differed in the resistance of the coil. You may find the following links useful. http://www.lightstraw.co.uk/gpo/clocksystems/pages/b131