There are some other uses of diversity modes which aren't common
in amateur practice, but might be interesting for special applications.
Pro-audio radio microphones use diversity receivers to minimize
signal loss as the microphones move. I believe, and Jim or Joe
will correct me if I am wrong, they transmit using FM. By
measuring the degree of quieting on the two receivers, the
combiner can decide which signal is better and route that signal
to the audio mixing board. Since the audio volume represented by
a FM signal is mostly independent of signal strength, good
quality audio gets to the board even as the system changes
receivers. This kind of system might be useful for amateur
weak-signal FM work.
The other interesting diversity mode I know of is the way the
costal commercial communication radio stations worked in the
1930's and later. They were using CW to send messages across the
oceans. Each station transmitted on 3 separate bands. The
receivers listened to all 3 bands and routed the "best" signal
to the operator. (I don't know how they determined the best
signal using 1930s technology.) Obviously a two channel version
could be assembled using a K3 with a sub-receiver.
A system where you can automatically determine which receiver
has the better signal, could be useful for RTTY. Measuring the
difference in signal strength of the mark and space signals
compared with the signal strength half way between them might be
a useful technique.
73 Bill AE6JV
On 8/8/15 at 4:37 AM, ve3...@storm.ca (Richard Ferch) wrote:
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.
-----------------------------------------------------------------------
Bill Frantz | gets() remains as a monument | Periwinkle
(408)356-8506 | to C's continuing support of | 16345
Englewood Ave
www.pwpconsult.com | buffer overruns. | Los Gatos,
CA 95032
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft@mailman.qth.net
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to arch...@mail-archive.com
