It s not perfect but definitely helps tune the if coils in the elenco am kit.
Ceramic resonator bfo circuit.
The last time i checked i didn t find it on the site but.
Inverters u1d e along with ceramic resonator x1 form a stable 0 5 455 khz oscillator.
Crystal oscillator vs resonator.
In conclusion has anyone any photos of a mini sized bfo circuit built with a ceramic resonator.
The circuit is extremely stable.
Nand gate u2b buffers the original unmodulated signal and its propagation delay ensures that its output is in phase with the output of u2a.
This i found easier that trying to set it up with the frequency meter.
More about making coils.
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 following circuit uses a 455 khz ceramic resonator which gives good frequency.
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.
The filter s center terminal normally grounded is connected to the current limiting resistor.
Perhaps they ll inspire me to build one hhny2all.
All about circuits.
I built this because at the time i didn t have a signal generator that would perform am modulation.
Oscillation is near 455 khz stable within a few hz.
The input and output of the ceramic filter are tied together.
Discussion in general electronics discussion started by richard9025 feb 5.
455 khz tunable bfo circuit reply to thread.
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.
Ceramic resonators ceralock lead type two terminal csbla series.
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.
Nand gate u2a is the modulator and provides a 100 square wave modulated signal.
A ceramic resonator will not allow you to move the frequency more than a little.
I want to make a 455khz tunable bfo without any transformers based on the model on this page.
Turn the receiver off and then on at any time and temperature the bfo frequency is exactly the same.
