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JT65-HF Amateur Radio software for reception/transmission of JT65A protocol with an emphasis upon its usage in the High Frequency Amateur Bands.


JT65-HF Setup and Use Guide


JT65-HF Setup and Operations Guide

Gúia (PDF) en español:

Vídeo de YouTube

JT65 frequencies JT65A frequency 20 meters 30 meters

JT65A frequency 
14076.0 kHz USB VFO

JT65A signal is about
+1.3 kHz to +1.5 kHz higher than VFO frequency.

JT65A Passband = 355Hz

JT65A frequency 
10139.0 kHz USB VFO

JT65A on 30m 10139.0 USB VFO Frequency
JT65A Signal Passband = 355Hz
JT65A is suitable for use in the 500Hz Bandwidth segments of ham radio bandplans.

The most popular JT65A frequency is in the 20 Meter band:
The JT65 frequency 20metres is 14076.0 kHz USB VFO.
The JT65a sync frequency is 14077.27 kHz.
The JT65 signal frequency is about 14077.3 to 14077.7 kHz.

The JT65A frequency 30metres is 10139.0 kHz USB VFO.

The JT65a sync frequency is 10140.27 kHz
The JT65 signal frequency is about 10140.3 to 10140.7 kHz*.
*Note: This transmit signal is within the 10140-10150kHz automatic digital sub-band.

International JT65A frequency 40metres is 7039.0 kHz USB VFO.
The International JT65A sync frequency is 7040.27 kHz
The JT65A signal frequency is about 7040.3 to 7040.7 kHz.

The JT65A frequency 40meters (USA) is 7076.0 kHz USB VFO.
The JT65A sync frequency (USA) is 7077.27 kHz
The JT65A signal frequency is about 7077.3 to 7077.7 kHz.

The JT65A frequency 17metres is 18102.0 kHz USB VFO.
The JT65A sync frequency is 18103.27 kHz
The JT65A signal frequency is about 18103.3 to 18103.7 kHz.

The JT65A alternate frequency 17meters is 18098.0 kHz USB VFO.

The JT65A frequency 12metres is 24917.0 kHz USB VFO.
The JT65A sync frequency is 24918.27 kHz
Note: before date 9/2011, the old JT65A frequency was 24920 kHz (changed to avoid QRM)


  • JT65A operators use USB VFO FREQUENCY for spots.
  • JT65A signal is about 1.3+kHz higher than the VFO frequency
  • The JT65A Passband is about 355Hz. Bandwidth is about 200Hz.
  • JT65A may be used in the 500Hz bandwidth segments of bandplans.
  • Normal operation of JT65A is a sync audio frequency of 1270.5Hz.
  • Sync tone is the reference mouse-click frequency for JT65.
  • JT65A signal bandwidth extends about 200Hz above 1270.5Hz sync.
  • The lowest tone of the JT65 signal is normally 1270Hz.
  • The system allows approximately +/-600Hz auto-tuning on receive.
source: specifications

JT65A/JT65/JT65-HF mode is normally used on HF, MF, LF and 6 meter bands.

Special Notes on Good Operating Procedure:

1. Operators should be careful of frequency selection, accurate clock, and calibration. Always listen and observe the waterfall spectrum of signals on the frequency before transmitting, and during activity.  

2. JT65A is a weak signal digital QSO mode. Always use very low power on HF to avoid QRM to other JT65 signals and other modes. 20Watts ERP is maximum for normal activity and DXing in the 40metre to 10metre bands.

3. Normal activity of JT65A is in the "weak signal" part of the ham bands, near the PSK, MFSK, and Olivia 500 frequencies. JT65A should not be used in parts of the ham bands where faster digital modes are in use.

4. The long tone carrier duration of JT65 transmissions has potential to cause severe interference to other modes.

5. Do not use JT65 in 10144kHz-10150kHz because JT65A is NOT COMPATIBLE with MFSK, FSK, HELL, OLIVIA, CONTESTIA, ALE400, or RTTY and can cause severe interference to fast time-sharing modes such as PACKET, PACTOR, ALE, PSKmail, and APRS.

Multiple JT65 frequencies are listed on some bands, due to:

A) Amateur radio band rules are different in some countries.
B) The need for alternate frequencies if QRM is experienced.
C) Local or regional interference on a main frequency.
D) Coordination with the changing spectrum utilization of the amateur community.
E) The high popularity of a new mode-du-jour  may create a temporary need to find a new or alternate calling frequency.
F) There are many competing modes in the weak signal part of the digital bands.

Es MUY IMPORTANTE tener el reloj del PC con la hora exacta, si es posible sincronizada por internet utilizando un programa tipo Dimension4 o cualquier otro que te sicronice la hora en el PC. Si no tienes la hora sincronizada vas a ver la cascada pero el programa no te va ha descodificar ninguna señal y cuando tx va ha pasar lo mismo que nadie te descodifica tu señal.

Si te pones en recepción en 14076, deberías recibir estaciones pero cada periodo de TX/RX son 48 segundos.

Las estaciones transmiten hasta el segundo 48 de cada minuto, el programa decodifica las señales recibidas entre el segundo 1 y 48.

En la página puedes controlar tu emisión.


Vídeo de YouTube

Vídeo de YouTube


FrequenciesSegment/Net nameModeCommentsWebsite
1836-1838JT65DigitalJT65 in USB 
1838JT65DigitalUSB dial freq.
3576JT65DigitalUSB dial freq.
7076JT65DigitalUSB dial freq.
10138JT65DigitalUSB dial freq.
10139-10141JT65Digital10139.0 kHz USB VFO Dial Frequency JT65 JT65A JT65B Calling (signal frequency 10140.27+)
14076JT65SSBCalling frequency for JT65 (weak signal) 
14076JT65DigitalUSB dial freq.
14076-14078JT65Digital14076.0 kHz USB VFO Dial Frequency. JT65 JT65A JT65B Calling (signal frequency 14077.27+)
18102JT65DigitalUSB dial freq. 
21076JT65DigitalUSB dial freq.
24917JT65DigitalUSB dial freq.
28076JT65DigitalUSB dial freq.
50.276JT65DigitalWeak Signal Users