5W Valve RF Transmitter circuit
Posted on May 3, 2017 12090
As we tune into the midwaves, the larger the antenna we need to place in the transmitter. For a medium wave antenna we use a copper conductor as long as possible. For the best result, the antenna should not form corners, but extend in a straight line and as high as possible from the ground. One end of the cathode is connected to the device and the other to the middle of the horizontal antenna or to one of the two edges, whereby the whole antenna is contiguous.
The transmitter amplifier consists of the ECC83 dual-triode and 6V6. The configuration is a protective mesh and is approaching 100%. The power supply uses a dry rectifier 220V for 100mA. We also use a transformer with a primary 220V and a secondary 6.3V to heat the lamps. Switch D1 is single-pole single-action and cuts off high voltage when we want to listen to other transmitters The range of the transmitter with a good antenna reaches 10-15 kilometers.