In the past, I used to purchase OCXOs and used rubidiums to stabilize the frequency of wireless devices and use them as reference clocks. At that time, I made a regulator/comparator that could lock the color burst signal of a TV broadcasting station to a 10MHz VCXO and tune the frequency to 10MHz to check whether it was correct as a true absolute frequency or to adjust the frequency. However, this type of equipment could no longer be used as soon as analog TV ended. However, it became possible to use a very inexpensive GPS reference clock, and OCXOs and rubidiums were no longer necessary. This is an adjuster/comparator that I made previously. I will be removing the TV tuner and encoder/CH display and installing an LCD for a reference generator using NEO6M instead. 　　　　　　　　　　　　　　　　        　click　 However, there are some station chiefs (cranky old men) who say they want to use an OCXO or a rubidium as the reference clock. For these cranky old men, I would like to introduce a regulator/comparator. 【overview】 The OCXO/rubidium output signal (10MHz in this case) must be a CMOS level pulse. If it is a sine wave or low level, you will need to use 74HCU04 to shape the waveform. The phase comparator is done between 1MHz, because the fluctuation frequency can be easily measured. In other words, if it takes 1 second for 12 rotating LEDs to make one revolution, the fluctuation is 1X10^6, and if it takes 10 seconds, the fluctuation is 1X10^7. Of course, it can be done between 10MHz, but if you use TC5081, you cannot use frequencies higher than 2MHz, so there is no problem using 74HC86 as a comparator. Each 10MHz output is input to U4 (74HC390) and divided by 10 to make it 1MHz. 74HC390 has two 4-bit counters built in, and each one can divide each 10MHz by 10. Each 1MHz output is phase-compared by U2 (TC5081), and the phase difference is converted to a DC voltage by the output of the LPF. This signal drives an LED with U1 (BA689), a 12-point level driver. The BA689 can be used in either level display mode or position display mode, but it is used in position display mode to light up a single LED to indicate the DC voltage level. Next, the NAND gate of U5 (74HC00) is used to select whether to use the clock from the OCXO/rubidium or the clock locked by GPS as the reference clock. This selected 10MHz is supplied to U6 and divided by 1/10, 1/10, and 1/10 by U6/U7 to output 1MHz, 100KHz, and 10KHz. The reference clock of this unit outputs four types of clocks: 10MHz, 1MHz, 100KHz, and 10KHz. In addition, to monitor whether the oscillator is operating properly, 10KHz is divided by 1/10000 by U8/U9 to drive an LED with a 1Hz signal. If you do not need this Ultraman LED, you do not need U8/U9. 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Reference circuit diagram　　　　 　I'll show you what my uncle made.　　JA4IYO production photos Furthermore, JA4AKI (Mr. Matsuda) has modified the LED rotation so that it rotates right/left in the phase lag flow direction and phase lead flow direction, so I will introduce it here. You may need to slightly modify R14/R15 at the joint. Since the signal supplied to the level driver needs to be a small level, it will saturate immediately if left as is, so adjust it with the added semi-fixed VR while watching the LED display rotation. Start with zero and gradually increase it to check the lighting. The phase detector is the default TC5081, and it is OK to supply the signal from CNP2�@ to the op amp (NJU7043D). However, when comparing at 2MHz or more, use 74HC86. 　　　　　　　　　　　　　　　　　　　　　　　　　　　　Added/modified circuits 　　　　　　　　　　 　　　　　　Introducing JA4AKI's video As stated on the "NEO6M" page, the locked state is when the comparator LED is stationary.