Re: Measuring the output power
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The NanoVNA cannot display power. The TinySA can. But you'd have to calibrate it and need a lot of attenuators to do so. Maximum power in is recommended to be -10 dBm. So with a 10 watt transmitter, you'd need 40 dB of attenuation. First attenuator in line should be capable of handling 10 watts.
Zack W9SZ
All Hams, IMHO, should have SWR meters, no matter the bands of interest.? Is essential for antenna work.
It's the 21st century, most hams should have a VNA by now ;-)
And they can display swaaaar too.
All for the price of a Mc Donalds Happy Meal these days,? far more versatile
and educational than a swaaaaar meter on it's own.
As for common power meters, well the problem with those is that they
are additive types unless you use something like a Bird with a frequency
selective slug, otherwise the power readings can be innacurate.
Additive types relying upon simple diode detectors for example will
not be much use of the TX has spurious emissions they get added
to the reading, as do harmonics.
For example 1st, 3rd and 5th harmonics can add to the readings.
But in fairness if you're just looking to read the power of something
like a properly functional FT817 where filtering is working correctly
and you just wish to customise the power settings or check supply
voltage vs power output then a bog standard power meter is good enough.
But no good for golden screwdrivered rigs, homebrew and malfunctioning
PA's.
You might need a speccy analyzer for that too, but they are cheap now.
Just give up eating donuts for a month and you can afford something
like a TinySA Ultra (and you'll be healthier too).
All sorted.
73 de Andy G0FTD
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