[Elecraft] TX Gain calibration fails

[William Hammond]

Hi Joachim , How are you adjusting the power in each of the three power settings.  Do you have the coax and dummy load connected directly to the K3?  Trade out the short jumper to the dummy load to assure yourself it is good.  After that, I would measure power with an external calibrated wattmeter.  The K3 utility is obviously not seeing the power it is looking for, low by .5 to 12 watts depending on the power setting.

73, Bill-AK5X 

> On Dec 30, 2021, at 11:53 AM, <dl7jp at gmx.net> <dl7jp at gmx.net> wrote:
> 
> Hi,
> 
> I tried to go through TX Gain calibration on my K3 (after VCO MD cal), but
> it fails (see below). Does anyone have an idea what to do in this case?
> 
> 73, Joachim DL7JP
> 
> -----------
> 
> Elecraft K3 Utility Revision 1.15.8.18
> OS Version 6.2 Build 9200 Windows 8
> K3 MCU revision 05.67. RS-232 speed 38400 bit/s.
> Starting 5 watt calibration
> Calibrating at 1.900 MHz
> Calibrating at 3.750 MHz
> Calibrating at 5.336 MHz
> Calibrating at 7.150 MHz
> Calibrating at 10.125 MHz
> Calibrating at 14.200 MHz
> Calibrating at 18.110 MHz
> Calibrating at 21.200 MHz
> Calibrating at 24.930 MHz
> Calibration power settled at "  4.5 W ;"
> Tx Gain calibration failed because transmit power did not reach the expected
> value
> 5 watt calibration failed
> Elapsed time: 47 seconds
> 
> Elecraft K3 Utility Revision 1.15.8.18
> OS Version 6.2 Build 9200 Windows 8
> K3 MCU revision 05.67. RS-232 speed 38400 bit/s.
> Starting 50 watt calibration
> Calibrating at 1.900 MHz
> Calibrating at 3.750 MHz
> Calibrating at 5.336 MHz
> Calibrating at 7.150 MHz
> Calibrating at 10.125 MHz
> Calibrating at 14.200 MHz
> Calibrating at 18.110 MHz
> Calibrating at 21.200 MHz
> Calibrating at 24.930 MHz
> Calibrating at 29.000 MHz
> Calibrating at 52.000 MHz
> Calibration power settled at "  38 W ;"
> Tx Gain calibration failed because transmit power did not reach the expected
> value
> 50 watt calibration failed
> Elapsed time: 49 seconds
> 
> K3 Tx Gain Calibration data written on 2021-12-30 at 18:45:57
> K3 Serial Number 07445
> K3 MCU revision 05.67. RS-232 speed 38400 bit/s.
> Elecraft K3 Utility Revision 1.15.8.18
> 1900 kHz TxGain LP  64
> 3750 kHz TxGain LP  19
> 5336 kHz TxGain LP  35
> 7150 kHz TxGain LP  54
> 10125 kHz TxGain LP  56
> 14200 kHz TxGain LP  12
> 18110 kHz TxGain LP  23
> 21200 kHz TxGain LP  42
> 1900 kHz TxGain HP  25
> 3750 kHz TxGain HP  32
> 5336 kHz TxGain HP  40
> 7150 kHz TxGain HP  33
> 10125 kHz TxGain HP  27
> 14200 kHz TxGain HP  12
> 18110 kHz TxGain HP  10
> 21200 kHz TxGain HP  06
> 24930 kHz TxGain HP  08
> 29000 kHz TxGain HP  04
> 
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