I have three SN74HC161N connected such that an overflow on the first triggers the second etc. (the normal ripple carry setup, where RCO feeds into ENT). The clock inputs of these are connected to a 1 MHz oscillator. The voltage in the circuit is 5V.
From what I can see from the data sheets (https://www.ti.com/lit/ds/symlink/sn74hc161.pdf and https://www.ctscorp.com/wp-content/uploads/MXO45_MXO45HS.pdf) everything should work properly. It seems like the maximum frequency for these counters would be 1 / 500 ns = 2.00 MHz, well above the 1 MHz frequency of my oscillators. I have verified that the counters work using a much slower clock (a 555 timer), but for some reason it doesn’t count when using oscillators (I’ve tried several of them). Have I misunderstood the data sheets (English isn't my native language), or am I overlooking something here?
Below are some pictures of the actual circuit. I've used yellow wires for ground connections (except the four going to LEDs). Red and orange (and one white) indicates power (5V). The green wires (and the longer oranges) are just used for connections between different counters. All capacitors are 0.1 µF, except for the one connected to the 555 timer (on the right) which is 3.3 µF. As the image shows, the long blue wire is connected to the clock inputs of the counters and is currently driven by the oscillator, meaning the 555 isn't really doing anything as for now.
Also a little note: In the schematic, the ENP, CLR* and LOAD* pins are directly connected to 5V, but in the actual hardware I've used green/orange wires to wire them together.
I apologise if my pick of colours doesn't seem natural, however my arsenal of wires is pretty limited at the moment (new ones arrive in a week or two).
The red and blue wires in the top left are connected to an Arduino Uno's 5V and GND pins.