24-08-2012, 10:10 AM
No Mark, I don't think so.
The object of the exercise was to check/test the calibration of the Marconi. and it's Input Impedance.
I set the Output of the J-2 to give 9dB on the Marconi scale, then inserted Resistance to reduce that reading to 6dB, ie half Power, while keeping the source voltage constant. That's half Power in my book, and that's what the Marconi claims to measure. The inserted Resistance should then equal the (Real Part) of the Marconi Input Impedance.
I should perhaps of measured the Input Voltage to the Marconi as a check, but I didn't. However, as I said, I was checking the Marconi, not my 'scope or AVO, which I trust.
In what way does your methodology differ?
On the switch front I've had a sweep round and failed to find anything reasonably similar. Has anyone got a scrap one?
Alan
The object of the exercise was to check/test the calibration of the Marconi. and it's Input Impedance.
I set the Output of the J-2 to give 9dB on the Marconi scale, then inserted Resistance to reduce that reading to 6dB, ie half Power, while keeping the source voltage constant. That's half Power in my book, and that's what the Marconi claims to measure. The inserted Resistance should then equal the (Real Part) of the Marconi Input Impedance.
I should perhaps of measured the Input Voltage to the Marconi as a check, but I didn't. However, as I said, I was checking the Marconi, not my 'scope or AVO, which I trust.
In what way does your methodology differ?
On the switch front I've had a sweep round and failed to find anything reasonably similar. Has anyone got a scrap one?
Alan
