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Products => Test Equipment => Topic started by: ko4nrbs on November 05, 2022, 01:39:38 pm

Title: Frequency Counter Input Buffer
Post by: ko4nrbs on November 05, 2022, 01:39:38 pm
Any suggestions for a buffer for this counter?
https://usa.banggood.com/1Hz-50MHz-High-Sensitivity-Frequency-Meter-Counter-Measurement-Tester-Module-7V-9V-50mA-p-1662557.html?cur_warehouse=CN
I tried a pickup coil but couldn't get it to pick up the signal.  I am trying to check the output frequency of an old Heathkit HG-10 VFO.  Its output is at 5 volts RMS open circuit.
Thank you,
Bill
Title: Re: Frequency Counter Input Buffer
Post by: BillyO on November 05, 2022, 02:30:58 pm
You could possibly make up something with a high GBP op amp.
Title: Re: Frequency Counter Input Buffer
Post by: ledtester on November 05, 2022, 02:49:16 pm
I have this kit and built it but I can't remember if it came with a schematic or not.

In any case, in this thread:

https://antiqueradios.com/forums/viewtopic.php?f=8&t=391757

I found a reconstructed schematic which shows the input section:

[attach=1]


Title: Re: Frequency Counter Input Buffer
Post by: ko4nrbs on November 05, 2022, 03:19:49 pm
Do you use an input buffer with it?
Bill
Title: Re: Frequency Counter Input Buffer
Post by: Grandchuck on November 05, 2022, 03:32:54 pm
You could try one of these:

https://www.aliexpress.us/item/3256802963755345.html?spm=a2g0o.detail.1000060.1.9ab4792duzHSa7&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.291025.0&scm_id=1007.13339.291025.0&scm-url=1007.13339.291025.0&pvid=9e709335-b039-46f3-b2ef-704b3131bb58&_t=gps-id%3ApcDetailBottomMoreThisSeller%2Cscm-url%3A1007.13339.291025.0%2Cpvid%3A9e709335-b039-46f3-b2ef-704b3131bb58%2Ctpp_buckets%3A668%232846%238113%231998&pdp_ext_f=%7B%22sku_id%22%3A%2212000024369199718%22%2C%22sceneId%22%3A%223339%22%7D&pdp_npi=2%40dis%21USD%213.76%212.9%21%21%21%21%21%402101d1af16676622808262566e0ffc%2112000024369199718%21rec&gatewayAdapt=glo2usa&_randl_shipto=US (https://www.aliexpress.us/item/3256802963755345.html?spm=a2g0o.detail.1000060.1.9ab4792duzHSa7&gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.291025.0&scm_id=1007.13339.291025.0&scm-url=1007.13339.291025.0&pvid=9e709335-b039-46f3-b2ef-704b3131bb58&_t=gps-id%3ApcDetailBottomMoreThisSeller%2Cscm-url%3A1007.13339.291025.0%2Cpvid%3A9e709335-b039-46f3-b2ef-704b3131bb58%2Ctpp_buckets%3A668%232846%238113%231998&pdp_ext_f=%7B%22sku_id%22%3A%2212000024369199718%22%2C%22sceneId%22%3A%223339%22%7D&pdp_npi=2%40dis%21USD%213.76%212.9%21%21%21%21%21%402101d1af16676622808262566e0ffc%2112000024369199718%21rec&gatewayAdapt=glo2usa&_randl_shipto=US)
Title: Re: Frequency Counter Input Buffer
Post by: ledtester on November 05, 2022, 06:05:49 pm
Quote from: ko4nrbs on November 05, 2022, 03:19:49 pm
Do you use an input buffer with it?

No I haven't used it with an input buffer. I haven't gotten around to using it with RF signals.
Title: Re: Frequency Counter Input Buffer
Post by: ko4nrbs on November 06, 2022, 04:53:05 pm
Hooked it up directly to my old Tektronix Constant Amplitude Signal Generator (Type 191) and the counter worked perfectly. 
Bill