ZS2EZ JT65 HF OPERATIONS

INTRODUCTION
After many years of VHF-only use, experimentation with JT65 on the HF bands proved that this mode was eminently suitable for weak-signal work on the sub-30MHz bands. A number of useful guides for use of JT65 soon appeared, most notably K3UK's Bozo Guide to HF JT65A and The BARTG guide to starting with JT65A on the HF bands

Despite these guides making the use of JT65 easier, many users longed for a more straightforward solution. This was addressed by Joe Large W6CQZ and his excellent JT65-HF software. JT65-HF is based on the code from the WSJT Project, but utilises a number of unique elements that make it uniquely suitable to HF operation. This software turned JT65 into an extremely popular mode on the HF bands - easy to use, requiring only simple stations and minimal power, it fast became the mode of choice for the "little pistol" stations. Sadly health issues forced Joe Large to abandon development of his software, but several other variants are now starting to appear from European authors.

During 2013 Joe Taylor K1JT released his WSJT-X program. This version of the now-famous WSJT comprises 2 primary modes - JT65 and JT9 - and is geared exclusively to the HF users. While this is very much a work in progress with new modes added regularly, it has taken the mode to a whole new level. Combined with Laurie VK3AMA's outstanding JT-Alert  addon (which also works with JT65-HF), the mode merges very well with most major logging software too.

The updated version of WSJT-X (version 1.7.1) requires users to compile ("build") their own installer files. Detailed instructions for doing this can be found here. WSJT-X 1.7.1 includes the new FT8 experimental mode.

During 2016, UA3DJY launched JTDX, a recompiled version of the opensource WSJT-X code optimised for HF use. This has gained extensive popularity and use on the HF bands, and is currently my application of choice. JT-Alert also supports JTDX.

SOME CONSIDERATIONS FOR USING JT65 ON HF:
JT65 is indeed an FSK mode in that it transmits distinct single tones from a tone set of 65 values. But.. JT65 is NOT TRANSMITTED using FSK. It uses AFSK and this is a critical distinction. Avoid ALC action if possible with an AFSK signal. Much like any other audio input to an SSB transmitter JT65 can generate a poor signal if over driven. JT65 is a weak signal mode. Its primary purpose is to facilitate EME (Earth->Moon->Earth) communications. For use on HF you need to re-think your power levels. Often a few milliwatts will do amazing things. Some situations call for much higher power levels, but in day to day HF usage, 10 to 20 watts is probably enough, if not too much.

MY ACTIVITY
ZS2EZ has been active in JT65 on the HF bands for some time now. Due to the slow QSO rate (at best a full QSO takes 6 minutes) it is very much restricted to lengthy operating times (which in recent months have been few and far between) but the mode does provide some astonishing surprises... and can be very rewarding!! I am currently working towards my WAS on JT65 (with confirmations via LoTW), and hope to complete this during 2017. Over the past 12 months I have been active on all modes from 80-10m, and when operating I log on to VK3AMA's HamSpots website.

I will gladly respond to sked requests for any band in JT65!!

Below is my table of US States worked and needed in my quest for WAS via JT65!

WAS on JT65 : My next operating goal

My contacts table:

STATE QSO
Alabama
WA4MIT
Alaska WL7CG
Arizona
WT9S
Arkansas
AE5DB
California
KG6WIK
Colorado
WB4CIW
Connecticut
W1VT
Delaware NY3C
Florida
AD5ZA
Georgia
WA4RG
Hawaii
KH6OO
Idaho
N7ESU
Illinois
WU9Q
Indiana
N9WKW
Iowa
AA0N
Kansas
WH6IO
Kentucky
K9AAN
Louisiana
AA5AU
Maine
W5KF
Maryland
AI1W
Massachussets
KT1B
Michigan
N8ABY
Minnesota
WB0SOK
Mississippi
KG5GCC
Missouri
W0MRM
Montana
Nebraska
K0IDT
Nevada
WB3JFS
New Hampshire
K1CF
New Jersey KI4KWR
New Mexico
AB5Q
New York
W2DX
North Carolina
K4MU
North Dakota
K0IDX
Ohio
KD8LCD
Oklahoma
N5AQ
Oregon
W7YES
Pennsylvania
KB3MOW
Rhode Island
K1QN
South Carolina K0PT
South Dakota
K7RE
Tennessee
W7ZP
Texas
K5NAA
Utah
KB7RUQ
Vermont
AB1NJ
Virginia
K1HTV
Washington
W7PSK
West Virginia
KC8RGV
Wisconsin
KA9SWE
Wyoming
WY7LL

LAST UPDATED : 7 MAY 2017

 

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