[Elecraft] Diversity RX and Speaker settings

[Jim Brown]

On 3/30/2011 9:40 AM, Rex Lint wrote:
>> Remember it is your BRAIN'S processing of the sounds that does the
>> >magic. Mixing the two audios into one signal prior to brain kills it.
> Not altogether:  With fading on one antenna and not on the other, then vice
> versa, diversity makes listening to the result copyable where it's NOT if
> you just listen to one or the other.  They don't have to be in different
> ears.  A lot of folks only have hearing in 1 ear, and diversity is still
> valuable!

Actually, you're both right.  There are time and phase differences 
between the outputs of the two receivers that are a result of different 
arrivals at the two antennas, and or the spacing of the two antennas, so 
mixing them ELECTRICALLY into a single audio channel can strongly 
degrade the received signal. This degradation does not occur, or is much 
less severe, if the two signals are mixed acoustically (that is, by 
feeding each to a different speaker). It is also minimized by mixing the 
two signals at un-equal gain -- that is, by using more audio gain on one 
RX than the other. This is one way that the "pan" configuration of the 
front panel audio gain control could be helpful.

Bottom line -- you should always listen in both ears if both ears work, 
but if you've got only one good ear, be very careful how you combine the 
two receivers.

73, Jim K9YC