Frequency Counter problem

Here is the data sheet https://sep.yimg.com/ty/cdn/ldb-cdpackaging/VC3165_manual.pdf . Requires about 120mV input. This particular model comes under a couple of different badges.

I bought a Velleman from CPC the same type, I sent it back within hours the display was very unstable.... I bought a Digimess UZ2400 (formally Grundig) the extra cash was well worth it and was a display item, far more sensitive and far better accuracy.

Shortly after I got the UZ2400 I was given a little battery Thander counter although only 200Mhz beats the Velleman hands down. This kinda thing gives me doubts about the Velleman and clones.

To boost the sensitivity what you'll be wanting is a broadband amplifier, usually a couple of transistors say MPSH10, there was such a circuit in Sprat G-QRP magazine a while back, even a MAR chip https://ww2.minicircuits.com/pdfs/MAR-1+.pdf , would probably do.

Dave

Is it working?

If your signal is below 60MHz try a 2n3904.

dare4444 wrote:Hi Jim,

Maybe you need to construct a simple one transistor buffer circuit with a high frequency transistor like S9018 or BF199. Do you have those on hand?

Check this circuit

https://ibb.co/W0q829c

The two 47ohm resistors set input and output Z. Select R for 1/2 the VCC at the collector. Let me know if this works.

 Thank you
I will try that as The simple passive circuits didn't work very well.

Hi Jim,

Maybe you need to construct a simple one transistor buffer circuit with a high frequency transistor like S9018 or BF199. Do you have those on hand?

Check this circuit

https://ibb.co/W0q829c

The two 47ohm resistors set input and output Z. Select R for 1/2 the VCC at the collector. Let me know if this works.

Hi Harry 
I have a Victor Frequency Counter   Model VC3165
It seems to be working just fine but I can't get a reliable count out of it. 
I am almost positive its because I don't have the proper Input circuit.
I have tried many I got off the net without success. The readings seem to jump all over 
like it would look if your were trying to measure a modulated Rf signal.  The meter came with 
Direct Probes and I know I need more than that to get a reliable reading. 
What do you recommend I do to fix this problem.
I don't use it much because I can rely on it's readings. 
Thanks Again
Jim