Project .. SWR - POWER Meter
SWR-POWER Meter. Project taken from Radiokit and created by Vittorio Carboni www.i6dvx.it. Characteristics: power from 1 mW to 1 KW, SWR measurement up to 4 after which the display shows ++++ (Danger!!). The creation essentially consists of two parts: the directional coupler (photo on the right) Teko 45 x 80 box with central shielding. Two pieces of RG213 cable from which the braid has been removed serve as primaries: the secondaries are made on an FT 82-43 ferrite with 20 turns of 0.8 mm enamelled wire wrapped around it. The other part is made up of the attenuator (resistors from 56 Ohm 390 Ohm etc.), the switching of the signals (FORW and REV managed by the PIC and switched with the 1N914 or 1N41418 diodes), the AD 8307 logarithmic amplifier and the digital part managed by the 18F4520 PIC which in addition to driving the display generates the switching signal and converts the voltage generated by the AD8307 suitable for display: in this regard, as can be seen from the photo, in addition to displaying the numerical value we also have two bars for immediate reading of the values. The calibration of the instrument is carried out via software. (there are no calibration trimmers) with the combination of the two buttons and turning on the instrument with the OK button pressed, you enter the Setup menu. The original version is made with various SMD components, while here we see that traditional components have been used. Obviously here we have a brief description: whoever is interested I am available to provide the original article, the drawing of the printout and obviously the software for the PIC or you can visit the i6dvx website.