EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: ko4nrbs on November 07, 2022, 06:37:51 pm
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If using this counter, what do I need in order to check the frequency on an old Heathkit HG-10 VFO? Its output is 5 volts RMS.
The counter:
https://usa.banggood.com/1Hz-50MHz-High-Sensitivity-Frequency-Meter-Counter-Measurement-Tester-Module-7V-9V-50mA-p-1662557.html?cur_warehouse=CN
Thank you,
Bill
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Do you have an oscilloscope probe?
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Yes, I do. I wanted to use this and keep it on while operating so I can constantly monitor my frequency.
Bill
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What I would do, and what I have done in the past, is hand wire a JFET or bipolar transistor follower into the oscillator to drive a coaxial transmission line going to the frequency counter.
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This is probably one of many "clones" of the pic based counter by DL4YHF https://www.qsl.net/dl4yhf/freq_counter/freq_counter.html (https://www.qsl.net/dl4yhf/freq_counter/freq_counter.html). If so, you will need to turn off the power saving mode (it may be off by default - I think it was off on mine). You can find the manual at https://www.qrpproject.de/UK/DL4YHFcounter.html (https://www.qrpproject.de/UK/DL4YHFcounter.html). Watch out for any preprogrammed offset - if you dont realise it is there then it can cause a lot of head scratching.
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Most DSOs -- even the inexpensive ones -- have a cymometer that will be more accurate & precise than that frequency counter.
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Yes, I do. I wanted to use this and keep it on while operating so I can constantly monitor my frequency.
Bill
What I would do, and what I have done in the past, is hand wire a JFET or bipolar transistor follower into the oscillator to drive a coaxial transmission line going to the frequency counter.
If you add a buffer like David Hess suggests (an excellent idea), it might be a good idea to control it with the transmit (PTT) line, or from the spot switch if your rig has one.
Otherwise you run a risk of leakage from the VFO-to-counter cable, which will be carrying a CW signal at your operating signal even while you are receiving.