Meanwhile some progress made My Trimble GPSDO 10MHz output 30mV tt amplified a filter followed by 3 stage amplifier then shaped by hex inverting Schmitt trigger 74AC14 a reasonable clean signal at 1296.210 Shielding and grounding and a clean 5V power are important the AM 350Hz hum side-bands are weaker -60 dB at 144.550 -40dB 1296.210 The ADF4351 REF in seems to be a straight TTL input without analog interfacing. It omits a trigger circuit. I had to make that myself. The specs only give the maximum signal level for this REF nothing about the shape or minimum usable level. It does not work with a relative weak or sinus shape 10MHz signal. Some other types PLL chips seem to have no issue with the reference level. 2V / division .5 uSec /devision 10MHz signal at the ADF REF input test setup 10dB / dev. discrete 10MHz booster 3 stage and a band filter after a lot of modifications this one can amplify the 3
Ham radio in JO33hg31 53.15N 6.35E