Ceramic Resonator Bfo Circuit

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.

Ceramic resonator bfo circuit. It s not perfect but definitely helps tune the if coils in the elenco am kit. The circuit is extremely stable. The input and output of the ceramic filter are tied together. 3 used transistor bc548 9 volt supply voltage rf signal is produced with 455 khz ceramic crystal.

The last time i checked i didn t find it on the site but. Ceramic resonators ceralock lead type two terminal csbla series. I want to make a 455khz tunable bfo without any transformers based on the model on this page. Nand gate u2a is the modulator and provides a 100 square wave modulated signal.

Turn the receiver off and then on at any time and temperature the bfo frequency is exactly the same. Crystal oscillator vs resonator. A ceramic resonator will not allow you to move the frequency more than a little. 455 khz tunable bfo circuit reply to thread.

I will try to get some photographs off to hans in the next day or so but life has been hectic over this weekend. Oscillation is near 455 khz stable within a few hz. 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. All about circuits.

The filter s center terminal normally grounded is connected to the current limiting resistor. In conclusion has anyone any photos of a mini sized bfo circuit built with a ceramic resonator. Perhaps they ll inspire me to build one hhny2all. 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.

This circuit was used to stop all the bfo drift. More about making coils. Nand gate u2b buffers the original unmodulated signal and its propagation delay ensures that its output is in phase with the output of u2a. The following circuit uses a 455 khz ceramic resonator which gives good frequency.

I built this because at the time i didn t have a signal generator that would perform am modulation. Discussion in general electronics discussion started by richard9025 feb 5. 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.