Friday, March 18, 2011


JT65A is a wonderful mode, and JT65-HF by Joe Large W6CQZ is a wonderful program that makes it enormous fun to operate. True, the mode only allows the exchange of signal reports, though a very brief amount of extra information (such as power and antenna) can be sent in a custom message. But so many contacts using other modes also only result in the exchange of such limited information. On the other hand, there is a certain magic in seeing faint musical tones sent by a faraway station translated into a message on your screen. Many people have said that JT65A is addictive. I agree.

If there is one problem with the mode, it is that the 50 second transmit cycles where nothing is decoded on to the screen until the end makes it easy for your attention to wander. I'm ashamed to admit it, but many is the time someone has replied to my calls and I missed it because my mind was elsewhere. So I was really pleased to discover an add-on for JT65-HF written by Laurie VK3AMA called JT-Alert. One of a pair of add-ons he has written (the other is a kind of macro tool for custom messages) it watches the decoded text and sounds an audible alert when a CQ call is received or when a station replies to your call. You can have different sounds for the two alerts, and the audible alert is optional and can be disabled. The tool can dock to the bottom of the JT65-HF window (as in the screenshot above) so the two function as one program.

I have been monitoring for activity on ten metres, which is dead most of the time. It would get pretty boring sitting in front of a blank window for hours at a time but I have set the CQ alert to a loud klaxon which will bring me running to the shack from wherever I am in the house if/when a call on 10m is received. It's a really useful tool (though it does get a bit annoying when working on 20m and my XYL isn't so keen on it either!)

I made a number of nice contacts on 20m using JT65A today, including CO2VE (Cuba), PJ2MI (Curacao) and LU6AM (Argentina). I also worked a fellow blogger, David K2DBK. Unfortunately my custom message to David didn't get sent as I got caught by a quirk in the JT65-HF program that was pointed out to me later by members of the JT65-HF support group. Apparently if you start a message with 73, those two characters are sent as a special shorthand sequence and the rest of the custom message is ignored. I had actually read that in the documentation, but I'm afraid due to the onset of senility RTFM often isn't the answer as I FTFM (Forget The Frigging Manual) immediately after I've read it. Oh well.  :(


David, K2DBK said...

It was really great to work you today Julian, and fun to see the screen from the other side. I'd run into exactly the same issue as you due to the long lag between having to pay attention, and am just about to grab a copy of JT-Alert myself. I've made a couple of really great contacts over the last few days, working VK3AMA on just 25w for my first-ever digital contact with VK (he told me he was running the same power to a 3 Element long path when we worked, via email), a 3D for a new mode some nice UA's and a smattering of other less-rare but still fun stations. And, of course, you.

Darn it, almost missed someone calling me while I was typing this. I'd better get JT-Alert quick!

Paul Stam PAØK said...

Hello Julian, nice contacts! Indeed, JT65A is very addictive. It's my favourite mode at the moment. The JT alert would be nice, but I still work with, old fashion way, the VOX and mic. So with a alert, that message goes into the air also. I disabled all computer sounds to avoid unwanted messages into the air. I like the slowness of JT65. Just right for me. How much power did you use for the contacts you made? For DX-ing I use 30 watts. I avoid to use much more, because it is not really necessary. I worked the Philippines with 5 watt JT65. Have a nice weekend, 73 Paul

Unknown said...

Hi Paul. I dodn't mention it but I agree, the slow pace of JT65A is one of the best things about it. If I go on the radio often I'm wanting to relax. Dealing with a pile-up is the last thing I want to do.

Normally I use 30W with this mode. But W3BI sent that he was using 5W ERP, which is better than 1,000km per watt.

Sivan said...

Thanks Julian for pointing out the availability of alerts. I was too was missing this feature. I also find it difficult to concentrate on what's going on when I have to wait 2 minutes to see if the other station replies. Same for finding that magic moment when somebody interesting shows up on 10m.

Jeff Davis, KE9V said...

Nice post Julian! I have enjoyed following your exploits with these exotic digital modes.

73 de Jeff, KE9V