Sensitive pre-scalers and input amplifiers

[TheDefpom]

Hi all
I have a couple of projects in mind, both need prescalers, but both also need to be pretty sensitive.

The first is to directly read a frequency using an arduino, but it needs to accept up to 40MHz, so a 10:1 ratio would work nicely (the same ratio suits my second project also), in my experiments anything over 6MHz input was unstable.

Input sensitivity needs to be in the region of 10mV minimum (again suits both projects)

My second project is to prescale a frequency counter input to allow signals of up to 600MHz (real world use) if it does a GHz that is fine too, I just wouldn't use it, like I mentioned a 10:1 ratio would be plenty (to try and keep both project circuits similar).

Basically I want to hear any suggestions of suitable pre-scaler options, or input amps etc, that would allow me to sense that low 10mV from 10Hz-600MHz, to hook into a prescaler to feed either an existing frequency counter, or an arduino.

I have purchased some NE5204 and NE5205 amplifiers, once they arrive I will have a play with those to see if they amplify the low levels the way I need them to.

[German_EE]

The input stages of most frequency counters use a chain of MMIC chips that both amplify the signal and clip it to the levels of the 5V/3,3V supply. In this case 'The Signal Path' has the information that you need:

[Marco]

We had a thread about a 10 dollar frequency counter before which also had schematics.

[TheDefpom]

Thanks for your input, that helped.

Anyone know of a prescaler that does a divide by 10, rather than the other more common ratios?