Your understanding of diversity mode is incorrect. What you described is
NON-diversity mode, i.e. normal or default use of the subRX. In this
normal subRX mode, the two receivers are on different frequencies - the
main RX (left ear) is on the VFO A frequency (upper display) and the
subRX (right ear) is on the VFO B frequency (lower display). The
transmitter is on VFO A if SPLIT is off, and on VFO B if SPLIT is on.
You can use this for split operation in either orientation (RX on A, TX
on B or RX on B, TX on A), or you can use it to monitor two frequencies
at once, and choose which of the two to work on depending on whether you
turn SPLIT mode on or off. You can also control which RX is/are heard in
each ear with a configuration option, but the default is A(main) left,
B(sub) right.
Diversity mode is quite different. In Diversity mode, BOTH receivers are
on VFO A (upper display). You would use a different antenna for each
receiver (otherwise there is no point) - because the two receivers are
using the same VFO and are phase-locked, the relative strengths and
arrival times of signals in the two ears gives you a kind of panoramic
soundscape, where the signal you want is localized at a particular
position in space (seems to come from a particular direction), while
noise is spread over the whole space, and QRM often comes from a
different direction relative to the signal you want. It's kind of like
stereo (diversity) vs. mono (non-diversity, both receivers on the same
antenna).
In Diversity mode, the lower VFO B display works just like it does with
a single receiver - it tells you where the transmitter will be when
SPLIT is on, but it has no connection with either receiver. Do not make
the mistake of thinking it tells you where the subRX is - that is only
true in non-diversity mode.
Normal non-diversity dual receive is usable in all modes, including
phone modes, although the level of activity and the likelihood of split
operation might be low enough in AM and FM that it might not be
economically worthwhile to add subRX filters for these modes.
Diversity mode is very useful in CW. It is not useful in digital modes
(unless someone can write software to emulate what the human brain does
with the inputs from two ears). I don't know how useful it would turn
out to be in wider bandwidth modes like SSB, AM and FM - never tried.
I don't know how the filters are installed in a factory build, but the
arrangement you suggested looks reasonable to me. I don't think there is
a hardware requirement to line the filters up in corresponding slots in
both receivers, but from a human interface point of view that makes
sense. Certainly that's what I did, and like you I left room for the
filters I thought I would be most likely to want to add later.
73,
Rich VE3KI
(unknown call sign) wrote:
My understanding of diversity reception is that I can receive two different
frequencies and though used more for CW when working pile-ups, it's not
something I'd likely use for FM, hence the single FM roofing filter. So I
was wondering about installing AM on the sub just so that I could have that
as well.
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