Local Oscillator TurningAfter replace the X'tal, adjust local oscillator frequency by turning the trimmer(photo 7, blue arrow). Frequency counter helps this adjustment.
- Receiving known frequency signal is also good way. I will show you a simple SG method. Fig 1 shows a simple signal generater(SG). This SG creates 48 times input frequency. Input 50MHz signal goes to 2400MHz.
- Setup the converter and SG.
- Put a short wire to the converter's N-type connecter as an antenna. Close to the SG(diode and resister) to the antenna.
- Set the 50MHz TX frequency and expected RX frequency. (ex. TX = 50.01MHz then SG creates 2400.48MHz. Set RX = 144.48MHz)
- Transmit 50MHz TX. Don't input much power. Less than 1w is better.
- Search RX signal and adjust to expected frequency by turning trimmer.
fig 1: simple Signal Generater
(by JA7BLS: CQ ham radio Magazine; Nov, 1990)