JT65 tips and tricks

and dos and don'ts

31 Mar 2016

I am just going to jump right in here. After using JT65 for a while, I am going to pass along these bits and pieces about JT65 based on annoyances I've seen.

1. Transmit opposite of their CQ. If they transmit CQ on "even" (aka even minutes, like 12:34 or 3:10), you transmit/respond on "odd" (aka 12:35 or 3:11). Most modern programs like WSJT-X and JT65-HF do the offset automatically once you click their name. Some older programs do not. Too often I have seen people, most recently people with the call signs W1JT and N6AS (as well as other "Extra" licensees) transmit even to respond to the other persons even CQ call. This is like using the public restroom and peeing on the shoes of the person next to you, its just rude, don't do it.
Transmitting even to respond to their even within the US is illegal as you are interfering with their transmission as well as preventing others from contacting them.

2. When using JT9, go above 2500. Most people have their programs set so they decode JT65 below 2500 and JT9 above 2500. Sometimes if it is slow people can be found in the 2000-2500 range, but for most busier bands like 20m and 40m, keep the JT9 above 2500. Also, try not to go above 3000 with JT9, since most modern radios using upper sideband cut off at 3000, many times you either will not be seen or they will not be able to respond (at least not without upping their frequency 100-200k). Only downside is these long time RRTY users many times come down as low as x.08MHz(2000 on the waterfall). What some people do is switch to fldigi, transmit on RTTY advising them they are interfering and need to QSY.

3. Repeat 3 times then stop. If you respond 3 times with the same message and they don't respond, stop transmitting (Halt Tx in WSJT-X) and let it run a cycle or two (2-3 minutes), someone else is likely transmitting on top of you and the other person likely cannot decode either of you. Let them finish their QSO and then try again. For some more rare DX like Russia or Uzbekicanistan, it may take you waiting several cycles before you can get them (just like any other rare DX pileups). If you watch the waterfall, many times you can see the other persons signal start just before yours, or you see a tail just after yours ends which can be a "tell tail" sign that someone else is also transmitting at the same time you are.

4. Update your decoder program to something more recent. WSJT-X is now at version 1.6.0, JT65-HF is at 1.0.93. If you are more than 0.2.0 versions off from WSJT-X, or 0.0.5 versions off in JT65-HF, then its time to update. Older versions may not have the updated "decoder" code to separate and decode nearby overlapping signals, or may not have the automatic odd/even setup.

5. If you use JTAlert or some cluster setup, don't just jump on when you see a new call sign, state or country, instead of getting a contact, you will likely be interfering with someone else's QSO, delaying you (and them) getting that contact even longer.

6. Stay off "1000". The 1000 mark is what is used for tuning, so if you want to call CQ, drop your bar so the right side is just below 1000 (850 or so), or move up a little so the left side starts around 1100. Try to leave the 950-1100 section open for people to tune. If you don't, then do not be surprised when you miss out on contacts as someone else properly uses 1000 as their tuning spot.

Hopefully this helps and feel free to contact me if you have any questions or comments.

73 de K4ISR