DIY RF Comb Generator for less than $1.00? After evaluating the mil-spec Herotek comb generator module and Pluto SDR clock source combination, decided to try out a low cost alternative for generating combs. With an on-hand SI5351A clock source, added two passive components (< $1 USD) to create adjustable frequency RF combs up to over 500 MHz. Details over at the QSL.net blog. #HamRadio #TestEquipment
https://qsl.net/n8dmt/rf-comb-generators-part-3-diy-combs/index.html
Close up photo of the TinySA-Ultra display showing comb pickets extending up to 500 MHz.
Close up photo of the protoboard showing a single blue capacitor in series from the CLK0 output (right) to shunt signal diode and output to spectrum monitor at left side of the blue capacitor. (Not worried about parasitics for this test.)
Desktop photo of the comb generator setup. SATSAGEN controlled Arduino UNO controlling EtherKit SI5351A clock source, with CLK0 feeding series capacitor on proto board to shunt signal diode with clip leads attached leading to TinySA-Ultra spectrum analyzer. A large number of comb signals are displayed on the TinySA.