There is now a slightly improved version of the firmware for the Juma TRX-2, version 1.07y Build 15.
The only aspect visible to the user is related to the use of the LDG Electronics Z-817 QRP Automatic Antenna Tuner. The Yaesu CAT emulation function has now been modified to permit automatic operation with this tuner. In addition, there are a number of internal optimisations and changes, but none of these would be visible at the user interface level. If you wish to utilise this autotuner, then download and install this version. It can be obtained by sending me an email, and I'll happily send you the HEX load file. If you have already loaded version 1.07y Build 10 (Available from this website.) then there will no need to re-calibrate your transceiver as the EEPROM mapping is identical. If you have not loaded 1.07y Build 10, then there will be a checksum error on initial start-up, this is normal, and only occurs the first time. If you have used my firmware previously, then please save your current calibration and configuration settings, if you are updating from the original firmware, then you will have to re-calibrate as the measurement system is quite different and the previous calibration values are invalid.
To use the autotuner, connect the RF output of the Juma to the input of the tuner, and the antenna to its output socket. You will need to make yourself a serial data cable to connect the tuner to the Juma RS-232 port, and if you do not have a cable, you will need to obtain an 8-pin mini-DIN connector and wire it to a standard 3.5mm stereo patch lead.
Set the Juma Serial Port protocol to YAESU-CAT, and set the port speed to 38,400 baud - the fixed speed of the autotuner. To match the antenna, press the TUNE button on the tuner, the following actions will occur:
1. When the TUNE button of the autotuner is pressed, the autotuner requests the current RX mode and frequency with the 00 00 00 00 03 command.
2. The Juma replies with the current mode and frequency which the autotuner stores.
3. The autotuner then requests the PKT mode with the command: 0C 00 00 00 07
4. The Juma responds by selecting the TUNE mode.
5. The autotuner initiates a transmit operation by sending the PTT ON command: 00 00 00 00 08
6. The Juma responds by switching to transmit.
7. At the completion of the tuning cycle the autotuner sends the PTT OFF command: 00 00 00 00 88
8. The Juma responds by switching back to receive.
9. The autotuner restores the previous mode with the set mode command: xx 00 00 00 07 where xx can have the value 00 = LSB, 01 = USB, 02 = CW, 03 = CWR.
Note that at the end of the tuning cycle the carrier is left enabled for 1.5 seconds to allow you to see the final SWR achieved, if that display has bee selected on the Juma prior to initiating a TUNE cycle. For full details, please read the Z-817 User's Manual.
If you do not intend to use this tuner, then there is no need to update the software unless you simply wish to have the very latest build.
73, Adrian, 5B4AIY
Email: adrian04@cytanet.com.cy
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