I have finished building the 1 kW ebay tuner and thought it would be a good idea to calibrate the power and VSWR measurment. So I hooked up a 100 Ohm carbon resistor to the output and with 50 Watts on 14 MHz I have set RV1 to 50W on the display and RV2 to a VSWR of 1:2. Then I checked all the other bands to see if I get the same results, here it is:
1.8Mhz: 55 Watts, VSWR 1:5.87
3.5Mhz: 52 Watts, VSWR 1:5.45
7Mhz: 51 Watts, VSWR 1:4.24
10Mhz: 50 Watts, VSWR 1:3.07
14Mhz: 50 Watts, VSWR 1:2.00
18Mhz: 52 Watts, VSWR 1:1.32
21Mhz: 51 Watts, VSWR 1:1.06
24Mhz: 48 Watts, VSWR 1:1.22
28Mhz: 47 Watts, VSWR 1:1.80
So forward power seems to be quite accurate, but why is the VSWR measurement so bad?
Please note: the resistor is pure carbon, it measures 1:2 on my nanoVNA from 0.5-30 Mhz.
Thanks and 73 de Jo PG4I
Jo PG4I