This is the schematic diagram of 40M band RF preamp with 3 tuned filters. Above image is an experimenter's 40 Meter band front end for CW. This has a double-tuned filter and a low gain, lower noise RF amplifier. This is a great circuit for isolation of a product detector or mixer in a popcorn receiver.
The second image is 40 meter band front end, double-tuned filter plus tuned common gate RF amplifier, they are already constructed on a single side PCB. Input and output Z is 50 ohms.
40M band RF preamp with 3 tuned filters, circuit diagram source page: www.qrp.pops.net This is a demonstration about 01A RF Amplifier which is build used old tube component to amplify the signal.
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