RCBG/Carl,
R.E. has an opinion.? Venders supply fact. Home brew is speculation and requires testing.
uBitx uses the latter, until tested its all a guess.? WHile patterned after many the transformers
are part of the picture and no commercial packaged design I've seen do those transformers.
However its widely copied and almost never tested.
The LO should be at least 5dbm and can be as high as 10.? Higher is better to a point.
The ubitx has maybe a 3dbm or less LO.? LEast that what I get with O'scope, SA, and
calibrated RF power meter.? Its not enough!
The suggested level is for a level 7 (7dbm nominal) DBM the input power should be -10dbm or less.
that is actually 17db below the LO.? ?So -20DBM is only 3db away and likely to make no
easily measured difference.
But if we peruse that at 3dbm we need to be at not more than -17dbm and the output signal
then is less than -22dbm.
Allison
