Making QSO's
First I want to make some QSO's with my transceiver, a FT-950, via the tuner, on 40meter. After tuning I set the power on 100W, the maximum of the FT-950.
- I set the freq on 7.035 MHz and tuned with 5W, that works fine. I increased the power in steps to 100W. The power gauge gave a
nice 95 watts. I saw in all measurements that the power meter is a bit low, about 5%. I have to calibrate that in the hardware or
maybe in the software it is easier. I will do that later. The SWR stayed exactly on 1.0. The linearity of the components is very good
and it makes me confident in the rest of the measurements.
- With 100W and a 100% tuned antenna, I had a QSO within a minute with G3UUV, OM Dick in Bath, UK. I got a 59 report and
received him with 57.
The red dot in the middle is the 50 Ohms of the cable coming from the transceiver or PA. Then a small circle segment downwards of the 205p capacitor, then a segment upwards of the set inductance (1.54 microHenry), then follows the segment downwards again of the 350 pF set capacitance, and last but not least a small segment leftwards of the small inductance of the appr 2x100nH inductance. Then we end in a red dot again, which is the impedance of the tuner output, 71.8 - j64.5 Ohms. This is the best match for the antenna, which has an impedance of 73.3 + j67.0 Ohms. It is not exactly the same as the output impedance with the imaginary part inverted, because of the loss in the tuner.
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