Receiving GB3UHF

Monitoring the beacon using WSJT JT65B mode

The use of JT65B enables the beacon to be received and monitored at extreme ranges, even when inaudible in a conventional receiver bandwidth. The use of JT65B will ensure that the user at long distances from the beacon can see if there is any enhancement to propagation, or if propagation conditions have deteriorated. It thus also allows automatic monitoring of the beacon over a period of time.

Software to decode the JT65B is easily obtainable on the Internet at the WSJT website

To decode the JT65B identification, tune the carrier to obtain a tone of 1500 Hz with the receiver set to USB, and the dial frequency reading 432.4285 MHz . The JT65B will then be tuned in correctly. The 1500 Hz AF originated from the "old" WSJT and specification when it was all centered around 1270 Hz. In WSJT-X, and MSHV, the AF definition has since been changed and WSJT-X can now receive tone 0 down to a couple of hundred Hz.

GB3UHF as received on JT65B by Colin G3SPJ

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