TTGO LoRa APRS

 Ostatnio bawię się przy APRS via LoRa

https://github.com/Qyon/TTGO-T-Beam-LoRa-APRS

SIT5156AI-FK-33VT-25.000000X (VCTCXO) and LNB SHARP bs1k2el200a

Works nice, upper part of waterfall vs lower part of waterfall is about 10 degrees C difference, and about 8 hours

@QO-100`s CW beacon

FOX924B-25.000 and LNB SHARP bs1k2el200a

Nope. This TCXO is digitaly controlled inside. It jumps:

@QO-100`s CW beacon

ASTX-H11-25.000MHZ-T and LNB SHARP bs1k2el200a

Nope. This TCXO has too much noise:

@QO-100's CW beacon

QO-100 and cheap PLL LNB SHARP bs1k2el200a

It works:

QO100 @ SHARP bs1k2el200a + 40cm offset dish + rtl-sdr

I was trying to make signal more stable, so I used AD9854 DDS + 10MHz OCXO. I replaced quartz with small transformer to make symmetrical signal. And this works ok.
Then i tried to feed it with 25788589.743 Hz to make QO's transponder available on 432MHz band. This works too, but SNR suffers about 10 dB loss :(

SHARP bs1k2el200a inside

DDS signal @25.5MHz

ADF5355 Python Class

https://github.com/Qyon/ADF5355

ADF5355 cheap chineese dev board on Orange Pi Zero mainline kernel overlay

 https://wiki.analog.com/resources/tools-software/linux-drivers/iio-pll/adf5355

/dts-v1/;
/plugin/;

/ {
    compatible = "sun8i-h2-plus";

    fragment@0 {
        target = <&spi1>;
        __overlay__ {
                        status = "okay";
        };
    };
        fragment@2 {
                target-path = "/";
                __overlay__ {
                        fixed_ref_clk: clock@0 { /* Fixed adf5355_regulator reference clock */
                          compatible = "fixed-clock";
                          #clock-cells = <0>;
                          clock-frequency = <26000000>;
                          clock-accuracy = <5>; /* ppb */
                          };
                };
        };
        fragment@1 {
                target = <&spi1>;
                __overlay__ {
                        adf5355@0 {
                                compatible = "adf5355";
                                reg = <0>;
                                clocks = <&fixed_ref_clk>;
                                spi-max-frequency = <1000000>;
                                clock-names = "clkin";
                                clock-output-names = "adf5355_out";
                                adi,charge-pump-current = <900>;
                                adi,muxout-select = <6>;
                                adi,reference-doubler-enable;
                                adi,mute-till-lock-enable;
                                adi,output-a-power = <3>;
                                adi,output-b-power = <3>;
                                adi,output-b-enable;
                                adi,output-a-enable;
                                adi,charge-pump-negative-bleed-enable;
                                adi,reference-differential-input-enable;
                                adi,muxout-level-3v3-enable;
                                adi,power-up-frequency = /bits/ 64 <123000000>;
                        };
                };
        };
};