DIGITAL ECHO

Nice circuit!!! you have to try this one. It can produce echo effect very good.The circuit very simple, consists of few passive components and one piece of digital echo chip IC HT8970. You can apply this circuit with pre amp mic or to make 3D effect of your sound system.It can be optimalized the echo effect by paralelling the input and output with the same circuit You can build two or four digital echo and paralelling the input to other input and output to other output, you can get sound very nice, if you combine with pre amp mic,the sound impressing like in the cave. If you want to combine with audio system, you can use this circuit to make 3D effect (suround)/ rear speaker pre amp.Sing jelas, regone murah hasile wah!!!!

LOW POWER FM TRANSMITTER

this is my first rf project.this tx using 9018 as oscilator, 930 as buffer, 710 as pre driver, 2026 as driver and 2053 as final. Total output power less than 1 watt. Although its too small, but it can reach until 5 kms using dipole gamma antena. I plan to increase the output power using 1971 but stil be posponed because 1971 is too expensive for me,RP 50.000. Besides of that, iam a newbie in rf, i'm scare doing mistakes that can destroy the 1971 . I dont understand yet about how to match the impedance of the circuit and the antena. I have ever hear that the mismatch between the circuit and the antena can destroy the circuit ,the final transistor exactly. Not only the missmatch that can destroy 1971 but also miss-tuned of the circuit.