And what is the name of the app? Where to find it? Thanks

 

If the iOS version has the same name as the Android version, then it's called Junghans MEGA.

 

Yes, also Junghans MEGA in the Apple app store, but I just searched for Junghans, that gives the same result. Glad to know there is also an Android version.

Just to be complete, the app transmits the time AND the date.

 

I tried using the Android version of the app to sync one of my MultiBand 6 G-Shocks (a GW-M850). I turned the volume up all the way on my tablet and placed the watch near one of the speakers, positioning it so it could get a strong (L3) signal. It took quite a while -- longer than the normal (4 minute) nightly sync -- but eventually it ended successfully, setting the received indicator on the watch. Unfortunately it set my watch back to standard time prematurely, so I'm not sure the app handles the U.S. DST flag data correctly (standard time starts on Sun Nov 1 at 2 AM). Also, the watch ended up about 0.3 second slow compared to another freshly-synced MultiBand 6 G-Shock (a GW-9110).

 

How does it compare to the Clock Wave app? I've used Clock Wave for quite a while and never had issues like you described.

 

The instructions in the app say: "The following special feature applies to the United States, Canada and Mexico: The Junghans MEGA [they mean the watch model] receives Pacific Standard Time after a succesful time synchronisation. As there are different time zones in the USA and the time changes of summer and winter time depend on the respective state, it may be necessary to set the time zone manually."

From this I deduce that when you select USA in the app, it sends a WWVB signal with the DST cue off, so you can't use your Citizen with DST setting Auto, but have to select DST On/Off in the watch yourself.

The instructions also say it will take "approx. 5 minutes (no longer than 15 minutes)" to sync. I think it took about 5 minutes in my case.

The 0.3 second difference compared to another freshly-synced (to what?) watch can have many reasons. All I can say is that my watch ended up perfectly in sync with the time displayed in the app, so my watch created no delay by itself. It might differ from a watch synced to a tower through the air because of the distance to the tower and/or because of lag in your device receiving NTP time, etc.

 

Thank you Citizenpromaster. Is good to now another way ( or app) to sincronize.
JJYEmulator works well for me ( PMD56-2951) but I will try this too.

Enviado desde mi Mi 9T mediante Tapatalk

 

Thanks a ton CP. Fortunately all my watches currently sync to a tower but there’s no telling when that might change and it’s good to know such an app is out there.

 

Actually the Junghans Mega App was released about the time Junghans released the Meister Mega. October 2018, IIRC.

 

True, the app is not that new, but it has flown under the radar of most people with radio controlled watches.

 

Man, this app worked great on my PMD56-2861, 2864, and 2951. Got them all synced up in about 2 minutes!

 

I can't quite wrap my head around how this works. If the watch is supposed to receive shortwave radio signals, how does audio from a cell phone create a sync? Or can the cell phone somehow generate radio frequency signals in the same band as the watch receives?
It clearly works for people, but I'm just trying to understand what is going on. Thanks!

 

The audio through the speaker or headphones generates a magnetic field that the watch can pick up. WWVB operates at 60 kHz on longwave, which is the third harmonic of a 20 kHz audio signal.

 

Yes, it is important to note that the audio/sound itself (air vibrations) is not of use, it is the audio signal, the electric current in the wire to the speaker (and in the speakers' voice coil), or the current in the wire of attached headphones, that generates a magnetic field around the wire and it is the third harmonic of the 20 kHz electromagnetic wave (60 kHz) that propagates from the wire/conductor, or in the case of the German 77.5 kHz signal, perhaps the fifth harmonic of 15.5 kHz, that can be received by the antenna in the watch. This magnetic field is always created by the current in the wiring to/in the speaker (and in a speaker with a voice coil this magnetic field interacts with a magnet so that the cone moves, creating vibrations in the air we perceive as sound). Harmonics can occur 'naturally', like when you pluck a guitar string, the string vibrates at the fundamental frequency and several harmonics, or overtones. The specific make-up of the overtones gives a musical instrument (and our voice) its timbre. However, in this case the (odd-integer) harmonics are what make up the square wave that is output by the DAC (digital-to-analog-converter).

As GaryK30 pointed out, 60 and 77.5 kHz is longwave radio, shortwave radio is in the MHz range.

 

OT Now I’m wondering how many other amateur radio operators are on here. Just got my license this summer.

 

OT Now I'm wondering how many other amateur radio operators are on here. Just got my license this summer.

There are at least a couple. WatchUSeek Watch Forums I only operate the radio in my car though...

 

Thanks for the explanation! To the radio experts: Sorry I confused SW with LW. I think of WWVB as something I pick up on my "shortwave radio," not really thinking about what band it actually is on!
What a neat idea to use speaker current as a signal.

 

Yes, whoever thought of that had a stroke of genius! When these emulators first appeared, some people on WUS thought the video demonstrations were a hoax lol

Later on, Clock Wave was developed by a Chinese brainiac, he even joined WUS to promote it (Clock Wave, a tool which can calibrate radio controlled...), but unfortunately for him there is now the Junghans app as a free alternative to Clock Wave (€ 2,29 in the Dutch app store).

You can even build your own transmitter at home using txtempus software and a Raspberry Pi, like WUS member FerrisAus did: My experience with txtempus (DIY alternative to radio...

 

I am having trouble getting my old U600 Skyhawks to sync. I have tried the iphone and ipad so far. Any pro tips for getting these to sync?

 

U600 is three band so you can try for Country Germany and USA and Japan. Then put the volume of your device on max and put the watch as close to the speaker as possible. If all you get is reception Low, then you have to find a way to amplify the signal.

 

I tend to make a 2 to 3 cm loop /coil of my wired earbuds, turn the volume all the way up, and tuck the watch in the loop with a 9 o'clock side facing in the earbuds.

Pro tip: if you have a JDM watch, set your device to UTC first. Then the watch will think it's home time is UTC, and it's easy to do offsets based on where ever you are.

Here's a bunch of watch as I used to own syncing together. The 2951 is the only one I have left. And that's just because I haven't gotten around to listing it yet. :-D

 

I tend to make a 2 to 3 cm loop /coil of my wired earbuds, turn the volume all the way up, and tuck the watch in the loop with a 9 o'clock side facing in the earbuds.

Pro tip: if you have a JDM watch, set your device to UTC first. Then the watch will think it's home time is UTC, and it's easy to do offsets based on where ever you are.

Here's a bunch of watch as I used to own syncing together. The 2951 is the only one I have left. And that's just because I haven't gotten around to listing it yet. :-D

Excuse the Noob question... just tried it with two Gs and no dice .. tried five times... just holding the phone close the the watch.

Are you connecting the wired earbuds to the phone? I am guessing this is to amplify the signal or somehow create an antenna.

 

I tried again with an External speaker .. no dice again. I'll have to find my wired earbuds.... ever since my wife got me the airpods.... wired ones are lost/forgotten.

 

Wow! Thanks for all the help.
I wanted to revive this thread anyway, as it is an awesome citizen WUS thread.
(a bunch of grown men huddled around a phone hoping and praying that their JDM watch syncs to a home-made RF signal)
Count me in

 

Here is how I did it this time, I just put the watch on the back of my Bose Soundlink II with both my iPhone and Bose on max volume, and I moved the watch around until I got High reception (as indicated by the seconds hand pointing to the red H), so I guess the amp circuit is somewhere near where the watch is in this picture. I was able to take this picture with my iPhone while syncing, because you can actually 'exit' the app and it will continue to transmit.

Syncing only took a couple of minutes this time. Last time I was holding the watch near the speakers on the front at a point that gave me High reception, but this is obviously easier. The two cables you see are power (the battery is pretty much dead) and AUX to connect phone to speaker, though I don't see a reason why it wouldn't work with a Bluetooth connection.

Again, since this is a JDM watch that only 'speaks' JJY and doesn't have World Time shenanigans, I select Country > Japan in the app, and that is all there is to it.

The funny thing is, I don't think that back in 2006 (when this watch was released) any of the engineers at Junghans, Citizen, Bose or Apple ever imagined someone using an Apple smartphone and a Bose portable speaker to sync a Citizen JJY radio controlled watch with an app from Junghans!

 

Last night my AS4050 only got Low reception from DCF77 in Germany, so I decided to see how easy I could get High reception without using my Bose. First I tried a loop of the AUX cable, but the watch got no reception at all. Then I decided to look up where the antenna is, that differs per caliber, and for the E670 it is at the 6 position (see image).

So I simply put the watch with the 6 position next to my iPhone speaker, volume max, Country > Germany (imagine the piece of toilet paper is my iPhone) and I got High reception!

On for example the U600 / U680 (below image) the antenna is at the 9 position, so be sure to check the manual for your watch, since a few cm more distance can be the difference between succesful reception and no reception, since the signal strength weakens with the square of the distance from the starting point (inverse-square law). In the above photo the antenna might be 2 cm from the speaker/wiring, and if I turn the watch around, it will be twice the distance (4 cm), and thus one-fourth the signal strength, which was not very strong to begin with.

I then tried syncing my PMV65 with U680, placing the iPhone speaker near the antenna, and I only got Low reception and it failed to sync, but after moving around a bit, I did get High reception and it synced within a couple minutes.

Those with a sharp eye will notice that the order (clockwise) of the reception strength is H > M > L for the E610 (PMP56) / U600 / U680 and L > M > H for the E670 (AS4050).

By the way, in case anyone had a brain fart, you have to force reception on your watch, otherwise nothing will happen ;-)

 

JJYEmulator+ Xiaomi 9T ( volumen max.) + PMD56-2951= WORKS FINE TO ME.

Enviado desde mi Mi 9T mediante Tapatalk

 

I have an old hand-me-down iPhone 5S, and I imagine the RF output will vary for different smartphones/tablets.

 

So @aafanatic, did you get it to work? Or is it just syncing at night to WWVB?

 

just some dumb question. can anyone detail step by step how to do this with an H145 movement?

my watch cant seem to get the audio signal from my phone even on max volume. do i need to do this on a quiet place? even though my watch is at +1 from the app, i would like my watch to be in sync with my phone and with my gshock

 

Try this tutorial and consult the H145 manual for how to force reception and for the location of the antenna. https://www.citizenwatch-global.com/support/pdf/h144/e.pdf

 

Just came across this app yesterday and was pleasantly surprised. I don't have a problem getting a direct sync on my Casio, but it's good to have a backup method which could come in handy when traveling. I've tried the Junghans app and it works great with my phone and watch. A couple of notes:

1. One big advantage of this app over the WWVB app is Junghans actually uses the NTP time rather than the phone time. The other apps I've seen use the phone time which at least on Android can be quite a bit off from NTP time.

2. On my Pixel if I turn the volume all the way up the app clicks for a second and then my phone reboots. I'm assuming it's overdriving the speaker. If I lower the volume a bit I can still easily hear the clicks and it works fine with no reboot.

3. I see some have a problem getting their watch to sync. On my Casio Lineage the instructions say to point the 12 o'clock position toward the radio transmitter, so I place the watch with the 12 closest to the phone speaker. In that Youtube video it appears Junghans suggests placing it with the 8 closest to the speaker. So it can vary depending on the watch brand and where the antenna is most sensitive. Here's a pic of what works with my Casio and Pixel phone with the bottom phone speaker firing forward: