Author Topic: The great DX mode: JT65A  (Read 18495 times)


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The great DX mode: JT65A
« on: July 04, 2013, 05:33:50 PM »
I posted this message in the Technical forum, because of the technical information I have at my JT65A webpage.  I think that I should post this here, as well... I hope you don't mind the duplication.

If you have not yet tried out JT65A, I'd like to introduce this digital mode to you.  The links, below, give the technical and operational details.

Have you ever wondered how much of the noise you hear on the HF bands is actually comprised of signals too weak to be copied? JT65A is a weak-signal digital mode that allows you to pull great DX out from under the noise on the high frequency spectrum. The JT65A communications protocol was conceived and first implemented by Joe Taylor, K1JT. Joe, a Professor Emeritus of physics at Princeton University, shares a Nobel Prize with Russell Alan Hulse (ex-WB2LAV) for the discovery of the first pulsar in a binary system as well as the first confirmation of the existence of gravitational radiation in the amount and with the properties first predicted by Albert Einstein. Joe has contributed to the amateur radio community in much the same way, changing the playing field for weak-signal operation.

( See a video where I use JT65A: )

JT65A is actually a "sub-mode" of Joe's original JT65 protocol, which he designed to optimize EME contacts on the HF and VHF bands. JT65 includes error-correcting features that make it very robust, even with signals much too weak to be heard. It was later realized that this protocol, with some adaptation, would also be very usable for terrestrial HF communications.

I have a page dedicated to information regarding JT65A:

Join the Facebook community for JT65A here:
73, Tomas David Hood / ARS NW7US = Heliophile / Omaha, NE

Web: and

Twitter: Space WX: @hfradiospacewx NW7US: @NW7US
Contributing editor, Propagation Columns: CQ Amateur Radio Magazine, CQ VHF, Popular CQ VHF


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Re: The great DX mode: JT65A
« Reply #1 on: July 04, 2013, 07:08:15 PM »
^ Those are very helpful pages on this mode. They got me up and running quickly and properly. Thanks for putting those out on the web.

I've been keeping an eye out for your call sign but haven't seen you yet. One of these days though.


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Re: The great DX mode: JT65A
« Reply #2 on: August 25, 2013, 08:05:17 AM »
Its a great mode.  Ive been using it for about 3 years and it gets better all the time.  Ive been running JT9 the last couple of weeks, and its awsome also.  It works wanders with very low power.  First Dx on JT9 was SV2CBN.  :)   Im running WSJT-X  V1.2 r3563      using my IC-7600 and Mosley yagi @60', but lots of verticles and dipole used all over the world with huge success...   73 and Good Dx

Dennis N0SMX
Elizabeth Colorado
« Last Edit: August 25, 2013, 08:08:17 AM by N0SMX »