Circuit above missing explanation. it needs two oscillator signals. They must be 180 deg different phase. Easy way to do is by using inverter between inputs.
tiistai 20. marraskuuta 2018
maanantai 19. marraskuuta 2018
sunnuntai 11. marraskuuta 2018
Multiband FM transceiver 145... 435...1297...2630 MHz
Handheld multiband FM transceiver with Touchscreen
Specifications:
Receiver coverage 145...2630MHz
Transmitter only radio amateur bands
145MHz TX Pout 1W RX sensitivity abt. -115dBm
434MHz TX Pout 1W RX sensitivity abt. -115dBm
1296MHz TX Pout 70mW RX sensitivity abt. -113dBm
2630MHz TX Pout 50mW RX sensitivity abt. -110dBm
Functional description:
Narrowband FM receiver with 2 if 45MHz/ 455kHz
Nextion touchscreen display with Arduino nano board.
Receiver does not have front end but RX sensitivity is reasonable.
Local oscillator ADF4350 development board. output 137.5 MHz to 4400 MHz
First lo mixer TUF-5SM spec.range20-1500MHz, +7 dBm LO signal, seems to be working upto 2600MHz
Mixer is quite immune out band intermodulations, even there is no RX front end.
FM modulation is done straight to ADF4350 reference clock.
Transmitter have power amplifier for 145 and 435 MHz, P out 1W. Made from RD07MVS1 fet.
Higher bands transmitter have only mmic amplifier P out abt.70mW
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