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Radio1950 · 5th Nov 2018, 3:35 am

In practice, I still think that the best method for the home workshop for HF is –

Divide the Power Meter into two parts, the “detector” (or reflectometer) and the “associated DC metering”.

You may have to unsolder the connections.

Sweep the “detector” across your required frequency range with a known good sig gen at say +10 dBM and external DC voltage meter (with suitable DC resistance load), to determine the frequency response of the “detector” at the low, medium and high frequencies. For HF, eg, this could be say 1.8, 7, 28 MHz.

Now that you know how the detector performs across the freq range, you can just use a HF transmitter at various power levels, and a 10x CRO probe, to calibrate your power meter at the low end of frequency, and within the specs of probe and CRO.
You can then rightly assume that it is acceptably accurate at the high end of your freq response of the detector.

All of this is covered by myself and others across many of the posts in this thread.
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5th Nov 2018, 3:35 am	#57
Radio1950 Hexode Join Date: Apr 2017 Location: Buderim, Queensland, Australia. Posts: 428	Re: RF power meter calibration In practice, I still think that the best method for the home workshop for HF is – Divide the Power Meter into two parts, the “detector” (or reflectometer) and the “associated DC metering”. You may have to unsolder the connections. Sweep the “detector” across your required frequency range with a known good sig gen at say +10 dBM and external DC voltage meter (with suitable DC resistance load), to determine the frequency response of the “detector” at the low, medium and high frequencies. For HF, eg, this could be say 1.8, 7, 28 MHz. Now that you know how the detector performs across the freq range, you can just use a HF transmitter at various power levels, and a 10x CRO probe, to calibrate your power meter at the low end of frequency, and within the specs of probe and CRO. You can then rightly assume that it is acceptably accurate at the high end of your freq response of the detector. All of this is covered by myself and others across many of the posts in this thread. .