Tom W0IVJ wrote:
>As long as the transceiver manufacturers give us transceivers with poor
IMD,
>it does little good to get the IMD on the amplifier good, unless you
home
>brew your own transceiver.
>
Transceiver and amplifier manufacturers will continue to give us poor
IMD for exactly as long as the major equipment reviewers (ARRL, RSGB and
DARC... but mainly ARRL) continue to remain silent.
In the final years of tube transceivers, the reviews show 2-tone IMD3
performance of -35dB(pep) and better. But as solid-state PAs came on the
market, those same reviewers presided over a gradual slide into the low
30s, the high 20s and now even the mid-20s... with never a word said.
Reviewers have consistently failed to understand is that they are not
only writing for people who might be interested in buying that
transceiver or amplifier. When they fail to speak out against poor TX
performance, they are neglecting an equally important duty towards
EVERYBODY ELSE who will have to suffer on adjacent channels.
(And before the tired accusations about "commercial pressures" begin,
the underlying story is way more complex than that. The main reason why
nothing changes is technical and human: all of the reviewers have become
complicit in the present situation, and none wants to be the first to
step forward.)
73 from Ian GM3SEK
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