Tag Archives: JT65

New NIST Time Code to Boost Reception for Radio-Controlled Clocks

A recent announcement focuses on consumer use of an enhanced time signal:

The National Institute of Standards and Technology (NIST) is changing the way it broadcasts time signals that synchronize radio-controlled “atomic” clocks and watches to official U.S. time in ways that will enable new radio-controlled timepieces to be significantly more robust and reliable.

This new time broadcast protocol will not only improve the performance of new radio-controlled clocks and watches, but will encourage the development of new timekeeping products that were not practical with the old broadcast system because of local interference or other limitations. For example, appliances such as refrigerators, microwave ovens and thermostats, as well as traffic light timers and sprinkler systems will be able to take advantage of this new phase modulation broadcast.

…..

Link: New NIST Time Code to Boost Reception for Radio-Controlled Clocks.

Could this be put to use for Amateur Radio? Is it accurate enough for time sync sensitive digital protocols like JT65? Would certainly seem to be potential option for a non-internet time sync.

Usually consumer gear only truly syncs one in 24 hours with a sub-second accuracy over the course of a day.

In theory the WWVB service could achieve 0.20 ms accuracy in sync, but this is fairly loose compared to some other time options.

Even at the end 2/10th second accuracy with twice daily full WWVB Sync JT65-HF should work (see: JT65-HF Source Document )

A WWVB receiver as a USB dongle for a non-internet connected PC?

This would seem to be a good workaround for high latency remote connected PCs, as what happens with many satellite ISP services.

You can read more about NSIT Time services at Link: WWVB Radio Controlled Clocks

Food for thought.

73

Steve
K9ZW

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Just the Contact, Nothing More – JT65 Mode QSOs

There are a good many people having a stab at running JT65 ( http://en.wikipedia.org/wiki/JT65#JT65 )

The mode is interesting as it is much about very precise timekeeping as anything. By very carefully syncing the transmitter and receivers software the receiver can complete reception below any normal communication mode.

It sort of reminds me of when I was once asked to be part of a team watching a particular window in a particular apartment building to see if the light was on at a certain time. In the midst of all the noise (all the lights going on & off in the hundreds of windows) that one particular window would be lit up at exactly a certain instance apparently meant something – afraid we were never told exactly what, but it much have been important!

Through timing a sequencing JT65 is hundreds of “little windows” that the software checks in a certain sequence at very specific times. That binary is parsed into a 13 character message from some 47 seconds churning!

I’d originally said I wouldn’t write about JT65 until I had logged 100 JT65 QSOs. Well I am not quite there but I think my thoughts have jelled.

JT65 is a QSO distilled down to nearly the least amount of data to transfer in meeting the most basic requirements for a QSO. Remember a QSO has a certain form – exchange of reports, call signs and such – you can find more on that at: http://en.wikipedia.org/wiki/Contact_(amateur_radio)

Ragchewing is simply not going to happen in a JT65 QSO – there is so little data being moved that conversation gives way to just the contact requirements of a QSO.

JT65HF Main Screen (from Users Manual)

JT65HF Main Screen (from Users Manual)

So what is JT65 good for? Well it does qualify as a QSO you can log and count for awards. It does work when conditions are very sour making even CW a task. It brings a challenge of very accurate clock timekeeping to the ham shack. I’ve found it works a charm as a semi automatic QSO process when doing other shack tasks that would make many modes difficult. It is a pretty fear-free way to try digital communications.

Using JT65HF Software a QSO is pretty well defined. Call CQ, Answer CQ Call, Send Report, Acknowledge and Return Report, RR Confirm and an optional 73. Each 13 character and the wait to decode takes about 48-50 seconds, and the next person doesn’t transmit until on the start of the next minute. A full JT65HF QSO is something like a 6 minute undertaking to exchange only the basics.

Yet what other mode can I work across the USA on 160m at less than 20 watts input (and my 160m antenna is most certainly a negative gain antenna) in awful conditions? Even interesting modes like Throb and Olivia are surpassed for rough condition basic QSO contacts by JT65HF.

Do I “like” JT65HF? When conditions are tough it does meet my needs to just reach out and confirm that I can make a contact. While it doesn’t warm up to my interest to learn about my fellow ham, understand his “operating conditions” and hopefully leave a favorable & friendly impression, it does work when almost nothing else does.

I’m impressed by the technology and cleverness of the mode.

It is also nice to have a communication alternative that is sort of mindlessly “point-and-shoot” and nearing QRP levels.

It is obvious the capabilities of JT65 have kept it alive on terrestrial HF bands for several years now. While it never will displace full conversational digital modes, it is neat and has its place.

I can see having the software on the machine and running some periodically. By the way, you get the JT65HF version of a pile-up as a Wisconsin Station on 160m. Apparently not too many fellow Packer Fans run JT65HF regularly. Here is a manual for JT65HF http://openhpsdr.org/wiki/images/0/0c/Jt65-hf-setup.pdf

Catch you on the air, broadcasting exactly on the top on the minute in JT65HF!!

All best and 73

Steve
K9ZW

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For Want of Nail, Nothing Like an Upgrade to Peak Interest, and Playing with Go-Kit Gear

In the run up to Dayton my Shack Computer had been acting up. Latency Spikes and gremlins that were giving PowerSDR no end of grief. Thought a decent dual-core Dell, I was even considering replacing the machine.

Troubleshooting found only erratic symptoms. The underlying cause(s) just weren’t easily found.

On return from Dayton middle son Winston KC9FVR/AG asked if we could run up the station so he could try some PSK31, having been reading the Digital HF book bought at the ARRL booth. We couldn’t get things to run very smoothly and after a very rapid shutdown in response to a sudden lightening storm powerful enough to set fire to buildings only 10 blocks away, the system would no longer recognize the Flex-5000A hardware.

Utilities and Testing showed that the OEM Dell Firewire card gave up the ghost.

Quick research at the Flex-Radio Knowledge Center & Forum Archives identified the best cards for performance and roughly $25 later a card was on its way rushing from Amazon.

Took the downtime to do ALL updates – from BIOS to any driver/software/system update that could be done. Also left the machine running a very in-depth anti-virus scan which ran overnight (all clean enough to pass).

The new card was truly PnP (Plug-n-Play) and despite having a different chipset than advertised (putting it into an OK-class rather than preferred-class for PowerSDR use) the system quickly reinstalled the “Found New Hardware” of the Flex-5000A.

Operator error led me to fight with VAC (Virtual Audio Cables) and settings – trouble I could have avoided by a simple reboot.

Once running it was lickety-split to help Winston KC9FVR/AG put a handful of PSK31 QSOs under his belt.

The drive that comes from a fresh license upgrade and an experimenter’s mindset had Winston KC9FVR/AG quickly asking – can I run fldigi from my Linux Thinkpad using some of your other gear?

So to the garage to raid the go-kit stash.

Up went the 20m Hamstick Dipole on 12 feet of surplus cameo-poles and a trial of a Small Wonder Labs PSK-20 I had ended up with somewhere along the way.

We had little joy with this setup, and it is uncertain if the PSK-20 is needing repairs or if we were struggling with Linux sound issues.

So out came the SGC-2020 Transceiver and the NUE-PSK Modem. This combination hadn’t really been used. The NUE-PSK modem had come back a few weeks ago from a full update at Midnight Solutions bringing it up to Version 5 with all the add-on features, and the transceiver had been run but once.

Plugged in the SGC-2020 and cabled up the NUE-PSK and “PING” we were on the air just that quick.

Winston KC9FVR/AG complete a QSO and then declared the micro-keyboard “worse than texting” and dug out an old full sized IBM clicky-clicky keyboard which worked wonderful.

Of course we weren’t about to read the manuals any further than the absolute basics to get things running, so we were hand-typing everything. Macros are for sissies (or for those who read the manuals).

Winston KC9FVR/AG downloaded a PSK31 app for his Android Phone and it was neat to see it decode from the speaker’s sound output.

I ran a handful of QSOs (it is sure a lot easier to type “K9ZW” than what it took him to type “KC9FVR/AG”) before we put the station away (took ten minutes to pick up everything and store it again.)

My go-kit HF gear did digital just fine! Power needs are such that I think I could get more than 12-18 hours of full duty out of each of the gell-cells I have set aside from their storage charge levels, and days if they were topped off first.

Remember that “spark of interest” that comes with a fresh license upgrade? Well it was back down to the shack to run a couple 20m & 160m JT65 demo contacts before promising each other that we would run some Hellschreiber on the weekend.

A couple things learned – in terms of the station the dead firewire card really put the main station out of commission. “For want of a Nail” they say the battle was lost, and for want of a working firewire port the station was off the air. Critical Key Component Dependency is not unique to an SDR setup, as most stations lack backups for mission critical items. Almost nobody has a spare for each item in their station.

Then the joy of seeing an inquisitive mind wanting to explore amateur radio shouldn’t be missing from an operator’s life. It was wonderful to help Winston KC9FVR/AG explore digital-HF and heartwarming that he would only let this father retire for the evening by making a promise for “more radios, more!” on the weekend!

And lastly that it is great fun to pull out the go-kit gear and give it a whirl. Couldn’t think of a finer father-son activity to put one’s work day aside.

73

Steve
K9ZW

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Just a Little Bit Longer – June 2012 to Add a Second

A neat thing happens this leap year – we’re getting a “Leap Second” in June! Brought to my attention by QRZ.com I wanted to see what this all was about.

The actual announcement:

INTERNATIONAL EARTH ROTATION AND REFERENCE SYSTEMS SERVICE (IERS)

SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE

SERVICE DE LA ROTATION TERRESTRE
OBSERVATOIRE DE PARIS
61, Av. de l’Observatoire 75014 PARIS (France)
Tel. : 33 (0) 1 40 51 22 26
FAX : 33 (0) 1 40 51 22 91
e-mail : services.iers
http://hpiers.obspm.fr/eop-pc

Paris, 5 January 2012

Bulletin C 43

To authorities responsible
for the measurement and
distribution of time

UTC TIME STEP
on the 1st of July 2012

A positive leap second will be introduced at the end of June 2012.
The sequence of dates of the UTC second markers will be:

2012 June 30, 23h 59m 59s
2012 June 30, 23h 59m 60s
2012 July 1, 0h 0m 0s

The difference between UTC and the International Atomic Time TAI is:

from 2009 January 1, 0h UTC, to 2012 July 1 0h UTC : UTC-TAI = – 34s
from 2012 July 1, 0h UTC, until further notice : UTC-TAI = – 35s

Leap seconds can be introduced in UTC at the end of the months of December
or June, depending on the evolution of UT1-TAI. Bulletin C is mailed every
six months, either to announce a time step in UTC or to confirm that there
will be no time step at the next possible date.

Daniel GAMBIS
Head
Earth Orientation Center of IERS

 Observatoire de Paris, France

Any place with a neat name – “SERVICE INTERNATIONAL DE LA ROTATION TERRESTRE ET DES SYSTEMES DE REFERENCE” – just has to be doing something cool!

As they describe:

Measuring the irregularities of the Earth’s rotation

The variability of the earth-rotation vector relative to the body of the planet or in inertial space is caused by the gravitational torque exerted by the Moon, Sun and planets, displacements of matter in different parts of the planet and other excitation mechanisms. The observed oscillations can be interpreted in terms of mantle elasticity, earth flattening, structure and properties of the core-mantle boundary, rheology of the core, underground water, oceanic variability, and atmospheric variability on time scales of weather or climate. The understanding of the coupling between the various layers of our planet is also a key aspect of this research.

The science surrounding their work must be interesting indeed! Space, Fluids, Gravity, Drag Aerodynamics, and more all rolled into one.

Their website is: http://www.iers.org/

For Amateur Radio about the only glitch may be a one time difficulty syncing JT65 (and similar time synced) protocols briefly. Would expect the rest of us won’t notice the difference.

Wonder how you log a 61 second long transmission in that one minute??!!

73

Steve
K9ZW

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The JT65 Mode – Minimalistic Contacts at a Glacial Tempo

Over the last week I’ve run some JT65 contacts, mostly on 160m.

These are truly “asleep at the wheel” style contacts, where 99% of what happens is one key click away with a key click needed ut once every two minutes, with any thirteen character message reception also spaced with two minutes in between.

Imagine Texting with only 13 characters allowed in slow motion with carried pigeon delivered texts!

On the upside it is a fun way to make some very long haul on not many watts.

I’ve found that the State of Wisconsin is very underrepresented on 160 meter JT65, which adds a bit of fun.

It is a stretch to put a JT65 contact in the same category as a full dialogue style QSO with freeform two-way dialogue.

JT65 is NOT a conversationalist’s mode. It is much more like contest contacts in slow motion with QRP power.

One of the keys is not expecting too much. You are not going to find out anything other than the other person’s Call Sign, Maidenhead Grid and Their Signal Report. Very simplistic content.

Next is getting a good time sync. Your computer needs to be accurate in respect to WWV to allow the software to work. Some variance may work out, but not a huge amount.

Last is to have something else to do in your shack. Believe me watching the software while it receives or transmits for 47 seconds on alterating minutes (one receive then the next transmit) is not going to keep you engaged!

Yet it is fun and the very low power is satisfying.

Hope to see you on JT65 perhaps 160m?

73

Steve
K9ZW

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K9ZW Joins the JT65 160m Affray

Decided I should give the JT65 mode a whirl after hearing how much success Scott W9JSB was having.

As I had earlier been on the 160m SSB Every Night Net, I thought I would see if there was any JT65 on 160m.

What a surprise as at 1.838 there is a raft of stations – at least that is what it sounded like “by ear.”

Downloading the JT65 software was easy – setting up things to work with PowerSDR and the Flex-5000A was a bit roundabout but doable.

The result was QSOs from the start!

Here is a screen shot of the software running (you can click to see a larger version):

K9ZW in a JT65 160m QSO with N4UPX

K9ZW in a JT65 160m QSO with N4UPX

All told I only made Eight JT65 160m QSOs – they take several minutes each – here is the calls and reports:

WA3WZR -17
N4UPX -08
WB2HTO -3
K4JJQ -08
VE9DX -03
N6KMR -10
K0IDT -04
W5GW -12

Went right back and added another ten QSOs:

AB8KZ
W9OL
KB3MOW
KJ4IZW
KA1QW
WT9S
KD8EZS
N4UFO
N4WD
WB4FSD

JT65 is a rather unusual mode in that it is about making the contact, and just about anything else is “chatter” and generally technically a difficultly.

Here is a descriptive and history of the mode: http://en.wikipedia.org/wiki/WSJT_(Amateur_radio_software)

The Project’s Homepage is at: http://sourceforge.net/projects/jt65-hf/

Flex had an article on configuration that was based on an older versions, but helped: http://kc.flex-radio.com/KnowledgebaseArticle50362.aspx

Definitely an interesting mode and I am sure I will play around with it a bit.

Hope to meet you on 160m JT65 sometime soon!

73

Steve
K9ZW

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