Electronics > Projects, Designs, and Technical Stuff

Frequency Counter and probes !!

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I have one Leader LDC-831 Frequency Counter, that got it as used before long long time.

Even so I have the box of it, but no users manual, or the original probe ( lead ).

And so I have to ask . 
Does the Frequency Counters use any specific type of probes ?

( Theoretically it depends on the Frequency ,
and so for the "150Mhz Max limit of the device" ,
I had build my own probe with BNC + RG-58 that splits in two crock clips )

If you have a picture of something more special , just post it.  ( 400X400 Max size ) 

For higher frequencies >20MHz you can use a standard 10x oscilloscope probe to reduce loading capacitive effects on the circuit. For lower frequencies your BNC + RG-58 setup should work fine.

Depending on frequencies, amplitudes and tolerated loading, either a simple coax lead, 1x scope probe or 10x scope probe should be fine. You might even want to use a 100x or 1000x probes if the voltages involved are very high. Note that unless terminated into their characteristic impedance (eg. 50 ohms), a standard coax cable represents a huge capacitive load, like 100pF/m (Xc = 1/(2*pi*f*C)). A 1x scope probe is better, and a 10x one much better. This limits the performance at high frequencies. For example, a 2m 1x scope probe may have a capacitance of 100pF, which at 100MHz will represent a load of 16 ohms. You will need a pretty beefy source to overcome that.

Not sure how to handle low-frequency compensation of 10x probes on a counter, you can't check for clean edge on a square wave, although I guess it's less important than for scopes.

if you need detail info start from basic my how do and dont on high frequency signal you can check here, How to Better Wire the BNC Connector and GHz issue the question is, what are you trying to do? my quick answer, you can mod your bnc cable and good up to few GHz, just cut out the crock clips, thats no good for high freq signal.


--- Quote from: Mechatrommer on May 29, 2011, 02:01:10 pm ---the question is, what are you trying to do?

--- End quote ---

1) I wish that I could see what the manufacturer of it, had in mind as probe for it.

2) The input voltage goes up to 20-20 P-P .
( but I solved this, by never have an direct connection with anything powerful above the 20Mhz )

3) At the range of the acoustic frequencies , the crocks works nicely.

4) When I was fine-tune FM PLL synthesizers, it was sensitive enough with out direct connection.

But mostly I care to see , how the original probe was look like.



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