This page documents the Junghans Mega 1, the first radio-controlled watch.
Junghans Mega 1 FAQs
- Does it still work? Yes! The Mega 1 uses standard radio time signals to synchronize an internal quartz clock once per day. This system is likely to be operational for a very long time. Later Mega models used other time signals as well, meaning that they work better outside Europe and synchronize faster.
- What about the battery? Junghans equipped the Mega 1 with a standard 3 Volt coin cell battery, CR2025. These are widely available and last 2-3 years in the watch.
- Can I replace the strap? The strap is proprietary and contains the antenna for the watch, so it is not practical to replace it with a third-party alternative. But it lasts a long time and OEM replacements are still available. And although it has an unusual attachment, it is easy to work with.
- Why does my watch show an “S” on the screen? This is “sleep mode”, and allows the watch to conserve battery power.
- Why does my Mega 1 show the time but not the date? Mine had the same issue – it synchronized the time but not the date in the USA. Then I brought it to Europe and it discovered the date! Perhaps the modern US time signal is not completely compatible with the Mega 1 after all.
- How can I improve time signal reception? I found that mine received the time much better with the band laid out flat rather than buckled. It also picked up the time better outside and in an airplane (!) than inside my house. And it takes it a while to synchronize and must be perfectly still for that to happen. Leave it flat on a shelf overnight and see if that helps.
- What is a Citizen Wave Receiver? Since it’s difficult for radio controlled watches to “hear” the 60 MHz signal in some places, Citizen produces a passive device to amplify them. It’s a tuned inductive coil wrapped around a soft iron core and focuses the signal to about 1 meter on either side of it. By all accounts, the Citizen Wave Receiver RCW/SU-3 really works well!
- Will the Mega 1 correct for different time zones? The Mega 1 does not correct for different timezones on its own – that’s what the two outer buttons are for.
Junghans Mega 1 Models
Although widely referred to as having a ceramic case, no production Mega 1 models were made in ceramic. All cases are coated brass.
There were six models of the Mega 1 in catalogs, each with its own slightly-different crystal, strap, and clasp. Shorter replacement straps were also available.
| Reference Number | Case Color |
|---|---|
| 026/0010xxx | Chrome |
| 026/0011xxx | Bright titanium |
| 026/0012xxx | Matte titanium |
| 026/0013xxx | Matte anthracite |
| 026/0014xxx | Dark blue |
| N/A | Grey (not produced) |