We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissable in your locale.

Author Topic: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020  (Read 110 times)

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 24441
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« on: January 22, 2020, 1141 UTC »
My first time catching this station, fairly weak signal, with a lot of the RFI crud that is characteristic of the modern longwave band.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 120 ft T2FD/ 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #1 on: January 22, 2020, 1148 UTC »
Which antenna were you using?

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #2 on: January 22, 2020, 1157 UTC »
Iíve got traces of a weak carrier on 40 kHz at 1152Z, but no where near strong enough to ID.

Iím using my KiwiSDR and a 1000 ft LOG.

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 24441
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #3 on: January 22, 2020, 1248 UTC »
Which antenna were you using?

This was using the KiwiSDR and 670 ft sky loop. Just checked now, and it seems to be gone, probably too late. I might try again tomorrow morning with a few other antennas.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 120 ft T2FD/ 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #4 on: January 23, 2020, 1151 UTC »
I listened again this morning.  You could just tell something was there ó without the waterfall it would be unnoticeable.  Strongest fade in was at 1121Z.  I need to try again a little earlier.

Some of the guys in my local ham club have been working JAís on 160 meters the past few days.  The solar minimum has been helpful for the low bands.
 

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #5 on: January 23, 2020, 1203 UTC »
BTW, the magic time for an ID is 15 and 45 minutes after the hour when they send JJY in morse.

It is going to be tough to verify what I am hearing is actually JJY.  On the French and German time stations I was able to get a correct time decode using the Kiwi decoders, so I was confident of what I heard.  This signal is so weak that a decode would not be possible, even if the Kiwi JJY decoder worked (it isnít operational yet).

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #6 on: January 24, 2020, 1124 UTC »
Not a trace of a signal this morning.  What was new was a RFI signal that wasnít present the previous two mornings.  The VLF spectrum was remarkable quiet until about 0600 local when a wandering RFI signal started up.  It went away for a little while, and then came back.  I suspect a neighbor has a grow light or something...

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 24441
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #7 on: January 24, 2020, 1306 UTC »
No luck this morning either. I had a signal on 40 kHz that sounded like it was producing two beeps per second.
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 670 ft horizontal loop / 500 ft northeast beverage / 58 ft T2FD / 120 ft T2FD/ 300 ft south beverage / 43m / 20m / 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline NJQA

  • Full Member
  • ***
  • Posts: 118
  • Midland, VA
    • View Profile
Re: JJY Japan 40 kHz Time Station 1140 UTC 22 Jan 2020
« Reply #8 on: January 25, 2020, 1118 UTC »
It has been a long time since JJY was on SW but they may have used something like two beeps/second there.

You donít usually see AM or CW keying on VLF though.  The antenna BW (because they antennas are so short compared to the wavelength) is extremely small and it becomes difficult to build an efficient antenna that has a BW wide enough to support AM modulation.

On-off keying (CW) is also difficult, particularly at power.  I think JJY is a 50 kW station.  Keying a large load on and off is hard on the electrical system and the power supply.  Still, from what I read JJY does send a CW ID, so they apparently do that.  WWVB uses a modulation scheme that raises and lowers power.

Most VLF stations today use a MSK.  It is efficient, has a constant carrier, and works with antennas with narrow bandwidths.  I donít know what JJY uses but MSK would be my first guess (and I emphasize that I am guessing.)