[Elecraft] Diversity

[Ed Cole]

One VERY IMPORTANT reason I chose the K3 with sub Rx was the fact the 
two receivers were in coherent phase, whereas Flex radio had two Rx but 
not in total phase.

I think diversity is tossed around as a loosely defined process.

In 2012 when I wanted a dual-Rx radio to process dual-polarity signal 
for use by MAP65, K3 was the only "game" available "off-shelf".  Since 
access is not provided to the IQ data stream in the K3, I had to resort 
to running two phase-locked LP-Pan (SDR) on the 1st IF's.  I had to 
modify the LP-Pan to have both in phase-lock on 8.215 MHz.

A few years later the IQ+ was introduced for use on 144 and 432 dual-Rx. 
  I is a SDR.  But one still would need a separate transmitter to operate.

Here is a block diagram of how I used my K3 (in diversity mode) in a 
dual-polarity adaptive receiver running MAP65:
http://www.kl7uw.com/MAP65.htm

Recently, I explored the SDR-DUO for use for noise cancelling and noted 
with adding ext ref, the two Rx were in phase-lock.  Later, I noted it 
tuned up to 3-GHz so would be usable on ham freq up 13cm (2.3 GHz).  I'm 
considering getting one primarily as a RA receiver on 21cm (1420-MHz).

I suspect there are more choices out there for diversity Rx, now days.

73, Ed - KL7UW