Tag Archives: JT-65

Changing Band Conditions

For the past three or four months I was having great success early in the morning with 40m JT-65 contacts to Asia on the 1/4 wave vertical antenna. The band would be great at around 6:45 am and be open till around 8:30 am. Japan especially would be easy to make contacts with on JT-65.

I have been noticing a definite shift in early morning 40m to Asia. First, I should note that JT-65 activity has dropped off quite a bit now that FT-8 is getting so rapidly popular. Just in the last few weeks I have noticed a drastic reduction in the number of JT-65 spots showing on pskreporter. The second observation is that the band seems to open to Asia a bit later now from about  7:30 am to about 8:30 am.

So this morning I started out trying JT-65 and made two contacts to Japan but there were very few signals on the waterfall. FT-8 had much more activity overall. I switched to FT-8 and started calling CQ DX and the first response was from Indonesia. The next 8 QSO’s were from Japan.

Overall, I have mixed felling about this. I enjoy the early morning pace of JT-65. I can check my emails while checking the bands. FT-8 takes quite a bit more work and attention. One other effect is that FT-8 is a bit more difficult to close a weak signal QSO. It is easy for the signals to drop below the noise floor and disappear between transmissions.


IC-7300 setting to work with WSJT-X (and others)

I prepared a short how-to on setting up and ICOM-7300 with WSJT-X for working digital modes. If you can get this working, other digital software can be easily configured in a similar fashion. The file can be found on the “Projects” page or from this link:

ICOM 7300 Setup with WSJT-X

More on the 20m Vertical Beam

The vertical beam is definitely directional. Unfortunately, I have no way to measure the gain. What I have noticed is that when I run this antenna on JT-65 I see much stronger reports from the direction the beam is pointed to versus the backside. Same goes with WSPR results. The antenna is also receiving well based on yesterdays WSPR challenge results as well.

I did some A/B switching between the beam and the 20m vertical while running JT-65. The beam sees signals coming in from Europe (very weak just above the noise floor). These disappear entirely when switching in the vertical. This could make a very nice antenna for next field day as it is easy to setup and from my QTH would cover much of the US my pointing due north.

Here is a picture of the antenna deployed in my backyard:


These pictures show how everything is connected:


At the feedpoint I have the homebrew 1:1 current balun. Each vertical element has two 18 foot radials laying on the ground. The two radial sets are connected by an 18.7″ ft wire. Pretty simple really.

ICOM 7300 – First Impressions

I spent some time playing with the new IC-7300 transceiver this weekend on various modes. My first comment is that having used an IC-7100 for some time I was instantly familiar with about 90% of the IC-7300 controls. Most of the buttons are labeled the same and many of the setting menus are also the same. First thing I installed was a headset adapter so I can use the Koss SB-45 headset. I needed a plug adapter (which I luckily had on hand) to plug in my Vibroplex paddles. Rig control via Ham Radio Deluxe was fairly straightforward as the USB drivers are the same as the IC-7100.  I started operating on 20m during the North America QSO party on Saturday with the 1/4 wave verticals.

My first impressions are that the rig works well (and possibly better) than the IC-7100 on SSB. My signal reports were solid 59’s and occasionally 59+ all across the USA. Also made some DX with favorable reports.  Receive options make it easy to adjust RF gain controls and filters to help clean up the signals. I like the overload indicator which tells me to back off on the preamp or RF gain or both. The main learning curve for me thus far is in using the scope screen. Once you play with this awhile you get used to operating more visually. You can see whats going on across the whole band and find signals to tune into or find dead spots where the frequency is open. It is also easy to switch in the audio monitor to hear what you are transmitting.

Also tested digital modes JT-65, FT-8 and PSK31 after configuring the software for the rig. The audio scope helps look at the signal quality on digital modes. I did not find any notable differences in using the 7300 vs the 7100 on digital.

So overall I am impressed by the new rig especially on SSB Phone. I’ll likely expand on this review as I get some more time on the rig but I am happy with what I have seen thus far.

The IC-7100 is now setup as my base VHF/UHF rig and I hope to play with DSTAR on it for the first time sooner rather than later. I will continue to have it connected to my PC for rig control and can switch in HF when needed.

Exploring a New Digitial Mode: FT8

Joe Taylor is testing a new digital mode called FT8. The development version of WSJT-X software now supports this mode. FT8 ( Franke-Taylor design, 8-FSK modulation) works similar to the more familiar JT-65 and JT-9 modes except the T/R cycle completes in just 15 seconds thus greatly reducing the time to complete a QSO. The bandwidth of the signal is 47 Hz and the decoding threshold is -20dB.


I downloaded the development version this morning and tried FT8 on 40m. There were just a few signals but I did close my first QSO. Pskreporter showed my signals was also being received in Australia this morning. Some things to note: Logging may not work and I understand that LoTW does not recognize FT8 as of yet. Also, the software autoexecutes the T/R sequence once the QSO starts. You have less than 2 seconds to select the station to respond too!


Working 40m and 17m this Weekend

I reconfigured what has become my main antenna, the 40m 1/4 wave vertical. This is still a temporary installation but I am growing increasingly happy with the results I am getting. I frankly can’t remember the last time I used the horizontal end fed. I have had to roll up the radials on occasion to mow the yard and have not yet deployed my permanent radials. Currently I am using the 30 foot travel mast from SOTAbeams to support the vertical wire and have four 27 foot radials deployed. I am using my homebrew 1:1 current balun at the feedpoint and running to the shack with 50 ft of RG-8X.

If I get the chance I’ll start operating around 6:30 am local time on 40m JT-65. I can usually snag several contacts in Japan with the occasional contact into Australia, Indonesia or the Philippines. The action is over by about 7:30am local time as the band closes quickly after sunrise.

Saturday afternoon, I was checking the bands and came across a strong VK station on 17m SSB. We exchanged signals reports in the 54 to 55 range. I moved over to JT-65 and found that there was DX activity including another VK contact. Today Sunday I am finding about the same conditions, great 40m propagation to the far east in the early morning and some light DX into Europe & South America on 17m in the late afternoon.


Transmit Power Using JT-65

I came a cross a very helpful web page in determining the amount of power needed for JT-65. It is called dbCalc and allows you to enter your transmit power and signal report and then calculates what your report would have been with other transmit power levels. I tried this out today on 40m JT-65, lowered my power in half and still made several DX contacts to Japan and Argentina.  You can easily measure how your signal is doing at a given power by sending a CQ and then checking the Pskreporter reports. Feed these into dbCalc and you can optimize your power settings for given band conditions. I suspect that in most cases operators are using a lot more power than necessary to make JT-65 contacts which makes it harder for weaker signals to get through.

40m QSO’s with 1/4 Wave Vertical

Most of this week was sent collecting WSPR data on the 40m 1/4 wave vertical. The vertical is holding up better to the breezy days after placing some duct tape on the joints of the travel mast. The vertical radiator is a 32 foot length of insulated #14 speaker wire. There are only four 27 foot ground radials deployed at this time. There is a 1:1 current balun at the feed point and about 50 feet of coax to the shack after that. Here is the SWR plot:


SWR is under 1.5:1 across the whole band with a resonant point 7.125 MHz. This antenna has been a solid performer on 40m without a tuner. I am noticing that the band starts opening up to DX about an hour before dusk. Last night I made several SSB contacts with Europe after 10pm local time.

Switching to 40m JT-65 at that time was very interesting as well  as the propagation conditions can be somewhat visualized with pskreporter. I really tested the JTDX software last night and have gotten the hang of the user interface which is subtly different from WSJT-X.  I set the IC-7100 with AGC-off and the bandwidth filter set to 3.6 kHz. Rather than search and pounce, I would look for a quiet spot at the extremes of the band and call CQ DX. This strategy worked well with many European stations answering. Over time, I can see my signals fading on the pskreporter map as eastern Europe’s morning progresses. As dawn approaches in Western Europe, stations start coming online and start to see my signal. At the same time, the opposite terminator starts approaching New Zealand and Australia and my signals starts picking up there as well. I knocked off at about midnight local time and picked up at about 7am and repeated. This time JA stations were answering my CQ and I was running a JT-65 “pile-up” with several JA stations calling at the end of a QSO.

Very pleased with the antenna performance on this band. 20m is acceptable through a tuner but the WSPR data indicates some degradation in performance over a resonant vertical or even the end fed antenna.

Operating this Weekend with a 1/4 Wave Vertical

The winds have died down a bit here at the QTH and the travel mast has been up about a week now. The duct tape on the joints may have something to do with it. On 40m, the antenna is a winner. Made contacts on SSB to Europe in late afternoon early evening on Saturday. Making JT-65 contacts into Japan is like shooting fish in a barrel on early mornings. On 20m, I run the antenna through the tuner and also made some DX into Europe and the South Pacific. I switched between the vertical and the horizontal DXtreme end fed antenna and found that the vertical can definitely hear signals that the horizontal cannot. Propagation conditions seems to be shifting these past couple of weeks. 40m is solid into Asia early morning and Europe in the early evening. 20m has been weak in the morning but picks up in the late afternoon. 17m has been really hurting lately with some small windows opening up from time to time. All in all a good weekend of radio activity.

Hints on setting up Receive on WSJT-X and JTDX

I spent some time reading the manuals for WSJT-X & JTDX to ensure that I was optimizing recieve. This seems to have improved after making the following changes:

  1. Make sure the PC is set for 16-bit 48,000 Hz sound card sampling.
  2. Turn off AGC
  3. Properly set microphone level. This is a two step process. In my case, I dropped the microphone level in Windows to 1%. Then using the Connectors–>ACC/USB AF Level control on the rig, dropped the level until I could get to 30dB receive with the slider at mid-scale. In my case the AF level was set to 10%.

These changes have helped with receiving weak signals. JTDX in particular typically decodes 15 to twenty stations when the band is busy.