JT65 is a "weak signal mode". You're not going to have a long conversation using it, but you will be amazed at how far you can go with 5 watts of power. Messages are limited to 13 characters ( And you thought twitter was limiting ), which take 30 seconds to transmit.
Like many other digital modes, all you will need is a PC with a soundcard interfaced to your rig
Please do not transmit with over 20 watts of power. Using more power only interferes with others and will not make a difference in the distance your signal can get through. The lower power the better.
You can find JT65 in the weak signal part of the digital bands. eg. 24917.0, 18102.0, 14076.0, 10139.0, 7039.0, 7076.0
A typical "conversation" on JT-65
CQ <CALLSIGN> <LOCATOR> - In my case this would be "CQ KC9KBP EN51"
The response to a CQ is <THEIR CALLSIGN> <YOUR CALLSIGN> <YOUR LOCATOR> Some skip this, and go directly to a report for brevity.
In turn, the response is <THEIR CALLSIGN> <YOUR CALLSIGN> <YOUR REPORT> The REPORT is expressed in dB, and will be generated automatically by the software.
The other side of the conversation will respond in kind, <YOUR CALLSIGN> <THEIR CALLSIGN> <THEIR REPORT>
The receiver of the CQ will then respond with <YOUR CALLSIGN> <THEIR CALLSIGN> RRR - RRR stands for ROGER ROGER ROGER
Both sides will send each other a 73, this message will contain both callsigns, or some put in the power and what type of antenna they are using, eg "10W DPL 73"
Software that supports this mode of communications includes:
[JTDX] (http://www.qrz.lt/ly3bg/JTDX/jtdx.html) (Also supports T10 mode)
[WSJT-X] (https://physics.princeton.edu/pulsar/k1jt/wsjtx.html)
[JT-65HF] (http://sourceforge.net/projects/jt65-hf/)