This is essentially a maintenance build, but there are a few minor changes from Build 3.
1. As with Build 3, the maximum RF output power in the Calibration & Setup mode is now set with the attenuator at -3dB which means the maximum output power is 5W - do not exceed this. See the previous post for details.
2. As I use the excellent Elecraft XG3 signal generator for receiver calibration and alignment I decided to make the reference frequency in the Calibration & Setup mode suitable for the default 20m frequency of this signal generator. Its default on 20m is 14.02MHz, and, as the transceiver is set to USB in the Calibration mode, the local oscillator is now set to 14.019300MHz so that there is a 700Hz beat note when calibrating the S-meter.
3. As a safety feature, the only time that RF output can be obtained is when the RF Power Meter calibration page is displayed. When this page is shown the transceiver is set to the TUNE mode, on all other pages it is set to USB. The reason there is no output on the other pages even when the PTT switch is pressed is that the microphone source is set to LINE which attenuates the microphone input signal by 30dB thus ensuring there is no output.
Note: The hardware design of this transceiver means that the PTT signal is hard-wired to the transmit/receive logic, and it is only sensed by the microprocessor. In the CW/CWR modes the paddle input is intercepted by the microprocessor thus the paddle transmit signal can be over-ridden if necessary.
Advantage is taken of this to ensure that the transceiver cannot transmit out-of-band in the CW/CWR modes. Unfortunately the only thing that can be done in the SSB mode is to set the microphone input to the LINE mode if the frequency is out-of-band. Whilst this will ensure that no speech signals are transmitted, if a data mode is being used then it is still possible to transmit out-of-band, but at least in all cases there is a warning message 'Out Of Band!' displayed on line 1 of the LCD.
4. As some people have been 'playing' with various combinations of the push buttons, I have added logic to the Calibration & Setup mode so that page changing is inhibited if the PTT switch is pressed.
5. An additional command has been added to the Serial Test Suite. In the previous firmware when dumping the Calibration & Configuration status with the 'u' command, the current frequency display format was illustrated. This has now be moved to a separate command. The 'u' command will still display the selected format, Original/New/Fixed-A/Fixed-B, but will no longer display an example.
To display an example of the actual format, use the new 'F' (upper-case F) command and select one of the formats, 0/1/2/3, whereupon the format will be illustrated. For example, if you enter 0 then the printout will be:
[12.345.68]
[ 2.345.68]
[ 0.345.68]
[ 0.045.68]
[ 0.005.68]
[ 0.000.68]
[ 0.000.08]
to illustrate how the Original display format would look with all combinations of frequencies.
6. There is some minor re-formatting of the Serial Test Suite's displays to align various data, as well as a minor bug fix. If, in either the LCD Test or the Frequency Display you deliberately entered an invalid character, then the display would be incorrect. Added a more robust user entry check so that even invalid characters are accepted, and converted to a valid selection.
7. When using the Voice Memory, there was sometimes a slight difference between the displayed elapsed time and the actual memory slot time - fixed.
As there are no EEPROM changes this can be safely loaded over a previous 1.11 or later version. As with all firmware updates, it is a wise precaution to make a note of your existing calibration and configuration settings prior to installing this build. There are pages at the back of the User Manual on which you can record your current settings. If you are updating from an original version, then you will have to re-calibrate, as the new measurement system is completely different.
With regard to the Elecraft XG3, this is an excellent inexpensive tool. It is a hand-held synthesised signal generator providing calibrated outputs of 0dBm, -33dBm (S9+40dB), -73dBm (S9), and -107dBm into 50 ohms. It is programmable via its serial port using the Elecraft configuration and control software package, and it can be used as a sweep generator, as well as being programmable with its own script language so that it can send CW or RTTY. Add to it the Elecraft 41dB adjustable 50 ohm attenuator and you have a very capable set of test equipment. I hasten to add that I have no connection with Elecraft other than as a satisfied customer, but can thoroughly recommend this equipment.
73, Adrian, 5B4AIY