VFO Frequency Check

[ko4nrbs]

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

[Grandchuck]

Do you have an oscilloscope probe?

[ko4nrbs]

Yes, I do.  I wanted to use this and keep it on while operating so I can constantly monitor my frequency.

Bill

[David Hess]

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.

[Swainster]

This is probably one of many "clones" of the pic based counter by DL4YHF 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. Watch out for any preprogrammed offset -  if you dont realise it is there then it can cause a lot of head scratching.

[colorado.rob]

Most DSOs -- even the inexpensive ones -- have a cymometer that will be more accurate & precise than that frequency counter.

[Hexley]

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.