Now the transverter/cb radio is able to receive 160-10 meter.
It consists of the folowing parts:
LO: sdr kits si570 vfo
Switchable bandpass filter: comes from russian ham parts
Power supply: Transformer taken from cb power supply
The Mixer is a sbl-1.
The LO signal is amplified by a bfy-90 amplifier. This signal drives the mixer.
The signal from the antenna is filtered by the bandpass filter. This board has a preamp as well. The filtered signal is connected to the mixer. The output of the mixer goes to the cb radio.
That is all that is needed to make a transverter. In this stage it is even able to transmit. Although the rf signal is very small (50mV pp).
The reception seems fine. But transmitting a clean signal can be a problem. On 24 and 28 MHz the 27 MHz signal may be too strong. Filtering it can be a problem.
I will give it a try anyway.
If it fails I will try the trick I described before. I will make a transverter from 27 MHz to 75 MHz. The LO for that transverter will be a fixed fixed frequency oscillator. Then I will use the VFO to mix the filtered HF signals to 75 MHz.
Supression of the 27 MHz signals is much easyer this way as 27 MHz is far away from 75 MHz
In fact I will have two transverters in series.
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