Frequency counter

[MNTSIDE]

Hello
Just starting out on repairing radios and was wondering if anyone had any suggestions on what frequency counter I should be looking at purchasing, getting a little confused with the input ratings,
1 Megaohms bs 50ohms
I’m assuming that a counter with an input of let’s say 30Mhz 1 Mohms would work???
Thanks
Kevin

 

[Lkaskel]

Something like this one would be a great start and its calibrated. I know this seller and he is good.

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[Handy Andy]

I’m assuming that a counter with an input of let’s say 30Mhz 1 Mohms would work???

The answer is yes, in short.

The longer wording / explanation is due to the type of measurements you'll be making - they are frequency based using low-power emitting oscillators - you don't want to change the tuning - just "see it" - so the 1MegΩ rating is better for toucing the output lead of a resistor from the output of that oscillator - than using a 50Ω type for low-power measurement references and checking thru proximity using an antenna (non-contact probe sniffer).

The reason I say the above is how you could load the circuit down too much - and not get a correct reading - unless you have a "High impedance" Otherwise known as "Hi-Z" inputs - which correlate to the 1MegΩ or 1,000,000Ω (A lot of zeros) versus Lo-Z or 50Ω (output tap sampler by proximity)

 

[MNTSIDE]

The answer is yes, in short.

The longer wording / explanation is due to the type of measurements you'll be making - they are frequency based using low-power emitting oscillators - you don't want to change the tuning - just "see it" - so the 1MegΩ rating is better for toucing the output lead of a resistor from the output of that oscillator - than using a 50Ω type for low-power measurement references and checking thru proximity using an antenna (non-contact probe sniffer).

The reason I say the above is how you could load the circuit down too much - and not get a correct reading - unless you have a "High impedance" Otherwise known as "Hi-Z" inputs - which correlate to the 1MegΩ or 1,000,000Ω (A lot of zeros) versus Lo-Z or 50Ω (output tap sampler by proximity)

thanks for the info andy