My First JT9 SOTA

Today KK1W, N1FJ, and myself activated Berlin Mountain, W2/EH-001. Jim and Frandy did CW and I figured I’d do JT9 to do something different. I set everything up, Jim spotted me, and I had my first QSO with M0TAZ on my second CQ. I thought I was off to a great start, but then on subsequent CQs I saw responses coming in on the waterfall but wasn’t getting any decodes. It took me about fifteen minutes of calling CQ to realize, “Hey, I think my clock my be off.” Sure enough, the clock on my netbook managed to gain three seconds overnight while the laptop was off. I’m thinking to myself, “now this is an easy fix.” I pull up a UTC clock on my phone and crack open Windows 10’s date and time settings. “Hmmm…” Windows 10 no longer lets you set the seconds on the clock. I fire up the hotspot on my phone (I’m lucky I had enough service to do so) and managed to get Windows to sync with Ahhh, everything’s synced up, and I’m getting decodes. Life is good. Except now, I ran into a new problem. This netbook (about 8 or so years old, 1.6 GHz Atom, 2 GB RAM) struggles decoding signals on a busy band (and my how busy and open to EU 20 was today). It was still decoding up to 10 seconds into the tx cycle! Luckily, JT9 is resilient enough to still be decoded even if you get a late start on your tx cycle. Now we’re cooking. I make it through 7 QSOs and as I’m sending my 73 on the 7th, the radio shuts off. I managed to kill my 6.6 Ah LiFePO4. I wasn’t expecting JT to be way more draining than SSB, but with a 100% duty cycle 50% of the time (so does that average to 50%?), it makes sense. Luckily, KK1W had a spare LiPO kicking around, so I cut back the power from 50 W to 25W and managed to make 3 more QSOs on 40 (I think at least two were chasers!).

I ended the afternoon with 10 QSOs and quite a few lessons learned:

  • My netbook’s CMOS has some really bad time time management. If I continue to use it, I need to figure out a way to sync time from the summit.
  • Microsoft decided that we have no reason to set seconds manually any more in Windows 10.
  • I need a new netbook that can better decode on busy bands. This thing is great for browsing but it has some issues on busy bands. Yeah it’s great on power, but Intel most likely threw away some instructions that would have helped decodes on these early Atoms.
  • I need to do some battery drain measuring to figure out the optimal tx power for my Ft-100D and my battery for the higher duty cycle of JT9 vs SSB.

All in all, I’d call the activation a success. I got to play with a new mode and get some chasers excited. I also learned a few things about portable JT mode operations. My question to everyone is this: Has there been a JT mode SOTA activation before, or am I the first?

Thanks for reading!

73 de Nick K1MAZ


Hi Nick,

Congratulations on what I think is the first JT9 activation. I know there has been at least 1 JT65 activation but I am fairly sure this is the first JT9. Its a shame I wasn’t aware of your activation as I would have definately been on the look out as it is my preferred mode from home.

I dont suppose you took a snapshot of the pskreporter map when you arrived home did you? Would have been the first thing I did to see how well it worked :grinning:

I had been considering it myself, but the main issue is using an old netbook with similar intel atom processor being slow on decode. One way around this (maybe, I havent actually tested it) is to run WSJT-X in dual JT65/JT9 decode mode and tune higher than normal say 14.079 and then set the split decode frequency so that it doesnt try to decode any JT9 below your transmit point. The initial frequency of 14.079 should see no JT65 receptions to decode and therefore will only try to decode anything above the “blue line”.

There are apparently some tweaks you can make in Win 10 so that you get the old Win 7 clock, which hopefully allows you to set the seconds value.

Hope that some of that made sense.


Windows 10 does allow the setting of seconds:

First turn off auto time setting:

Then scroll down to additional date, time and regional settings:

Then click on set the time and date:

Followed by the change date and time button:

And finally you can change seconds here:

More steps than before but it’s still possible in Windows 10.

Then of course you could simply open a command prompt and type TIME !!!

Easiest to sync time on summit is GPS!


Thanks for the JT9 Activation, Nick.
I was waiting for you to come on the air. When you did, I discovered my software was not working (I had not used it in months, but don’t know why it failed). I uninstalled and reinstalled. I figured I had missed you, but I guess our problems coincided. I was no sooner back on the air than I saw your CQ. Thanks for the digital points.

73 George N1GB

I saw your spot while activating NPOTA from Saratoga. I tried to do a Park to Summit call, but discovered that JT9 is not included in FLdigi’s large suite of modes. Maybe next time.

I heard W9BS in Florida working MW6XBE/P on 40m JT65 this morning at 0650 UTC. I don’t know if the MW6 was a SOTA station, because I couldn’t hear him - skip too long. I see from PSK Reporter that MW6XBE/P heard me at 0640! (I looked him up on and his home QTH is Bristol.)

Walt (G3NYY)

JT-9 is a weak signal mode so 25 or 50 watts is not really necessary. Try it next time with 5-10 watts and it should still be as good and save the battery life a bit.

73 Glyn