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Products => Test Equipment => Topic started by: ko4nrbs on November 09, 2022, 02:32:28 pm

Title: Frequency Counter Buffer Project
Post by: ko4nrbs on November 09, 2022, 02:32:28 pm
Has anyone built this?
https://www.nutsvolts.com/magazine/article/build-an-rf-frequency-counter-buffer-for-hf (https://www.nutsvolts.com/magazine/article/build-an-rf-frequency-counter-buffer-for-hf)

Thanks,
Bill
Title: Re: Frequency Counter Buffer Project
Post by: nctnico on November 09, 2022, 02:52:22 pm
Wouldn't a standard 1:100 oscilloscope probe with a BNC adapter do the trick?
Title: Re: Frequency Counter Buffer Project
Post by: ko4nrbs on November 09, 2022, 02:57:27 pm
Wouldn't a standard 1:100 oscilloscope probe with a BNC adapter do the trick?
Yes.  Wanted something I can use to monitor the VFO frequency of my old AM transmitter while operating.  I have used a commercial demodulator and sampler to view the transmitters output while modulating the output. 

Bill
Title: Re: Frequency Counter Buffer Project
Post by: mag_therm on November 09, 2022, 03:32:01 pm
I made a buffer from vintage sw receiver vfo to a PLJ_0802-C frequency display (with IF Offsets).
It is just a FET- Bipolar HiZ to 50 Ohm with a RG 174 coax to the display in another chassis.
input level 50  to 200 mV.
Title: Re: Frequency Counter Buffer Project
Post by: ko4nrbs on November 09, 2022, 04:48:03 pm
I made a buffer from vintage sw receiver vfo to a PLJ_0802-C frequency display (with IF Offsets).
It is just a FET- Bipolar HiZ to 50 Ohm with a RG 174 coax to the display in another chassis.
input level 50  to 200 mV.
Which FET- Bipolar HiZ did you use?
Bill
Title: Re: Frequency Counter Buffer Project
Post by: mag_therm on November 09, 2022, 05:16:50 pm
I made a buffer from vintage sw receiver vfo to a PLJ_0802-C frequency display (with IF Offsets).
It is just a FET- Bipolar HiZ to 50 Ohm with a RG 174 coax to the display in another chassis.
input level 50  to 200 mV.
Which FET- Bipolar HiZ did you use?
Bill

Home-brew 2n4416 into a 2n3904 as emitter follower

Edit :
Fet_Bi_Buffer qucs circuit with bias voltages:
https://app.box.com/s/74j8faqyjbk1xsjudkw7ngy9s4q5jnyi