Ceramic Resonator Bfo Circuit

Discussion in general electronics discussion started by richard9025 feb 5.

Ceramic resonator bfo circuit.

Turn the receiver off and then on at any time and temperature the bfo frequency is exactly the same. Nand gate u2b buffers the original unmodulated signal and its propagation delay ensures that its output is in phase with the output of u2a. More about making coils. A ceramic resonator will not allow you to move the frequency more than a little.

The objectives of if alignment are to ensure that all tuned circuits in the if stages are tuned to the same frequency and that this frequency is the correct frequency usually 455khz. I taped a short length of wire from the output across the back of the circuit board and then adjusted the slug to give me the correct note. Crystal oscillator vs resonator. I will try to get some photographs off to hans in the next day or so but life has been hectic over this weekend.

3 used transistor bc548 9 volt supply voltage rf signal is produced with 455 khz ceramic crystal. This circuit was used to stop all the bfo drift. All about circuits. I m enthused with your reference to the ceramic resonator bfo you described as well as by the other references in this forum but i m eager to see a pico sized bfo circuit that can accompany my shirt pocket sized grundig pe100.

I want to make a 455khz tunable bfo without any transformers based on the model on this page. It s not perfect but definitely helps tune the if coils in the elenco am kit. Inverters u1d e along with ceramic resonator x1 form a stable 0 5 455 khz oscillator. The last time i checked i didn t find it on the site but.

Oscillation is near 455 khz stable within a few hz. Hi thanks for the comment. Nand gate u2a is the modulator and provides a 100 square wave modulated signal. Just curious for input at this point i m not an egineer so i can t directly contribute to our community with such a pico sized hack.

The filter s center terminal normally grounded is connected to the current limiting resistor. The following circuit uses a 455 khz ceramic resonator which gives good frequency. Perhaps they ll inspire me to build one hhny2all. The circuit is extremely stable.

Ceramic resonators ceralock lead type two terminal csbla series. The input and output of the ceramic filter are tied together. This i found easier that trying to set it up with the frequency meter.