>Wayne gave us a way to read out what the ATU settings. >Does anyone have the formula or formulae for using "CT or CA and the L and C values to determine the impedance presented to the ATU?
The K3 tuner looks like an L network with series L and shunt C that is placed either on the antenna side or transmitter side of the inductor. When the shunt capacitance is on the antenna side the impedance of the antenna is higher than 50 ohms. When it is on the transmitter side the antenna is showing less than 50 ohms. Right now I show on my K3 CA = 0.16 nF and L = 0.70 uH, I am matched at frequency of 7.025 MHz. I now start cheating and use a program called L TUNER at: http://www.smeter.net/feeding/l-network-terminating-impedance.php I click on the L TUNER link and run the program (does not require installation) and choose the topology (series inductor shunt capacitance on the output or right side, network #1). I would choose network #3 if my capacitance value was on the transmitter side. I then enter the inductance of 0.7 uH, capacitance of 160 pF (convert from nF shown on K3). Enter generator impedance (K3 transmitter) of 50 Ohms. And now enter frequency of 7.025 MHz. And the program computes the following values for the terminating impedance of the network assuming a proper conjugate match to the 50-Ohms resistive load of the transmitter: Series Resistance R = 67.9 Ohms Series Reactance X = -8.8 Ohms Mike Scott - AE6WA Tarzana, CA (DM04 / near LA) NAQCC 3535 K3-100 #508 / KX1 #1311 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
