JMH/JMH2/JMH4 Japan Meterological Agency Radio Fax

JMH/JMH2/JMH4 are a set of radiofax stations transmitting from Tokyo, Japan. They had many more transmitters formerly – hence the “gaps” in the numbering, luckily they haven’t discontinued the service altogether.

Transmissions are all made at 5kW, and all three frequencies (center) at 3622.5khz, 7795khz and 13988.5khz have been heard from Sydney, Australia. Generally, the 7795khz is the best frequency, with 13988.5khz only available for limited periods, and 3622.5khz is severely affected by noise and static.

Unfortunately, I haven’t been able to find any contact at JMA for QSL requests – so I won’t get a QSL for this one, but that’s okay. Receiving the images are most of the fun anyway! Transmissions consist of white-tone for tuning, followed by a short start tone, then regular phasing. During the image, the margin is negative (black), and end of transmission is marked by a short stop tone followed by black for about 5 seconds.

Lets start off with the “unusual” faxes. Time will be given in local time (UTC+11) for the end of the fax. All reception done on JMH2 at 7795khz.

Test Fax – 6th Feb 2013 ending 0010


Test Fax – 7th Feb 2013 ending 0009


Test Fax – 8th Feb 2013 ending 0009


This is a test fax – note how over the case of several days, the propagation is completely different and the quality of the fax varies significantly! I guess it reinforces the need to be patient and persistent if you want to get a good copy!

Trouble Fax – 5th Feb 2013 ending 0403


Trouble Fax – 5th Feb 2013 ending 0321 trouble_20130205_0403

Normally a rare sight – these are trouble faxes which are sent when there’s something wrong with the system. In fact, I was able to receive three of them – but I’ve put the two clearest ones up here.

Regular Faxes

Surface Analysis – 5th Feb 2013 ending 0158


Sea Surface 100m Temperatures – 6th Feb 2013 ending 0135


Unknown – Pairs of Charts 1 – 8th Feb 2013 ending 0450


Unknown – Pairs of Charts 2 – 8th Feb 2013 ending 0521


Unknown – Pairs of Charts 3 – 8th Feb 2013 ending 0532


Unknown – Pairs of Charts 4 – 8th Feb 2013 ending 0543


MTSAT Satellite Image – 6th Feb 2013 ending 0627


Mean Sea Surface Temperatures – 6th Feb 2013 ending 0315


Ice Conditions – 6th Feb 2013 ending 2138


Unknown – Four Charts – 7th Feb 2013 ending 0608


48h Surface Prognosis – 7th Feb 2013 ending 2118


24h Wave Forecast – 7th Feb 2013 ending 2259


24h Wave Forecast – 7th Feb 2013 ending 0648


Wave Analysis – 7th Feb 2013 ending 2328


Unknown – 7th Feb 2013 ending 2059


Unknown – 5th Feb 2013 ending 2138


Which covers all of the different sorts of charts that I have seen when monitoring JMH stations.

About lui_gough

I'm a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!
This entry was posted in Radio and tagged , . Bookmark the permalink.

Error: Comment is Missing!