Re: [K3] Diversity Reception and Antenna Directivity

Posted by Bill W4ZV on Sep 16, 2010; 4:49pm
URL: http://elecraft.85.s1.nabble.com/K3-Diversity-Reception-and-Antenna-Directivity-tp5537531p5539351.html

David Gilbert wrote

Playing around with this stuff got me thinking, though.  What if I fed
the output from two VERTICAL antennas into the K3 receivers in diversity
mode, fed the audio output of both receivers into the A and B channels
of the computer sound card, and used an application that introduced an
adjustable delay in one audio channel before summing the two channels
and doing the D/A translation back to monaural audio?  Wouldn't that
have the exact same effect as being able to adjust the phase of the
incoming RF, and therefore the directivity of the 2 element vertical
array?  

Good idea, already implemented by MFJ, DXE and others:

http://www.mfjenterprises.com/Product.php?productid=MFJ-1025
http://www.dxengineering.com/Parts.asp?ID=1227&PLID=215&SecID=114&DeptID=12&PartNo=DXE-NCC-1

This reminds me of one SDR guru who proposed using 4 SDR transceivers to emulate a 4-square.  A multi-K$ solution to a $350 problem (i.e. one 4SQ controller box)...not to mention the need for 4 separate feedlines, 4 amplifiers, etc.

73,  Bill

P.S.  I believe one problem with what you proposed above is that phase would need to be readjusted every time you touched the VFO...i.e. phase is locked (i.e. meaning the phase differential is fixed) but the actual phase offset between the two RXs changes each time the synthesizer changes.  Lyle can correct me if I'm wrong.