[Elecraft] WSPR & Diversity RX

[Edward R Cole]

WSPR is designed to take only one audio input (one Rx) so it will not 
do diversity receive.
The K3 and K3s only output a single audio stream (main Rx or sub Rx 
when properly set up, but not both).

So what Don say is correct for the stock radio with sub-Rx, but...

Full diversity receive is possible (using dual receive sw:  Linrad or 
MAP65).  But you have to add more equipment to enable this.  I did 
that for dual-Rx on 2m-eme by adding a breakout of the 1st IF for the 
sub-Rx and connecting the 1st IF of both the main and sub Rx to two 
LP-Pan units (working as SDR) who I slaved to one LO so the two 
signals would be phase-locked and the two IQ baseband audio would 
stay in phase.  Those four lines go to a two channel stereo soundcard 
(M-audio Delta44) which produces the two IQ data streams to a 
computer for each receiver in the K3.

But you have to have a SDR sw which accepts dual-RX input to obtain a 
diversity result.  At present only Linrad or MAP65 do that.  WSPR is 
not included as option under MAP65 and I do not think Linrad can 
support it, either (less certain about Linrad).

So there is a diversity solution to provide two signal streams but no 
dual receive vers of WSPR.  I wonder if one might be able to run two 
essense WSPR on one computer with each taking input from a 
receiver?  You still would have to manually compare WSPR output from 
each to determine which has the better signal.  A good computer geek 
might be able to write an interface to both WSPR to compare each and 
outputting the best result.

Here is how I set up my dual-Rx 2m-eme adaptive receiving 
system.  With it I receive 2m in both Vertical polarity and 
Horizontal polarity with MAP65 providing the best signal reception 
(plus providing the actual signal polarity angle):
http://www.kl7uw.com/LINRAD.htm

So not exactly correct that diversity reception of digital modes is 
not possible; it is for JT65 with the addition of the necessary equipment.

73, Ed - KL7UW


---------------------------------
From: Don Wilhelm <donwilh at embarqmail.com>
To: MaverickNH <cbjesseeNH at comcast.net>, elecraft at mailman.qth.net
Subject: Re: [Elecraft] WSPR & Diversity RX
Message-ID: <0d1cfa26-19bb-a09b-93dd-e6bf695ffd82 at embarqmail.com>
Content-Type: text/plain; charset=windows-1252; format=flowed

Bret,

Since the computer soundcard is working only with one channel, diversity
mode will not help - unless you can create an 'add-on' to interpret both
channels and decide which one has better reception.

When using Diversity Mode, you listen with both ears to the left and
right channels and your brain figures out which is the better side to
listen to - one channel from the main RX and the other from the subRX.
With digital modes, the soundcard is listening only to the left channel
- main RX.

Yes, you have antennas that will do diversity for you, but that will
only be useful in voice modes and CW because the human brain will
automatically decipher the best signal from the two channels - you
listen to diversity with one channel in each ear.

73,
Don W3FPR

On 9/30/2016 5:36 PM, MaverickNH wrote:
 > I'm wondering about my K3S in Diversity RX on Digital modes, such as WSPR. I
 > have a G5RV and a 43ft Vertical, so was thinking I might find better overall
 > RX with Diversity enabled. Thoughts on this?
 >


73, Ed - KL7UW
http://www.kl7uw.com
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