[Elecraft] Dual Receiver Tricks

[David Gilbert]

Not sure what you are describing.  If you mean two antennas feeding two 
receivers at RF for diversity reception, yes ...  that works well but is 
not the same thing at all.  Your brain is doing some spatial processing, 
but it doesn't peak or null.  It also, as is apparent from the antennas 
you cite, compensates for polarization changes that would otherwise 
cause fading ... but it isn't peak/null.

If instead you are talking about being able to adjust phase and adding 
or subtracting the result, that can be done at RF but it definitely 
requires additional hardware.  You can't get there with just the K3 or 
K4 as is.

And none of what you describe would give you a numerical azimuth (or 
elevation) indication as the original post described.

Dave   AB7E


On 6/25/2019 6:19 PM, Bill Johnson wrote:
> Dave, the two receivers fed from two antennas give you what you are 
> looking for at rf level.  It works super well.  On upper bands I have 
> used SteppIR short vert with dipole.   My experience has been 
> excellent vs single antenna.
>
> Bill
> 920-421-1172
>
> ------------------------------------------------------------------------
> *From:* elecraft-bounces at mailman.qth.net 
> <elecraft-bounces at mailman.qth.net> on behalf of David Gilbert 
> <xdavid at cis-broadband.com>
> *Sent:* Tuesday, June 25, 2019 7:07:55 PM
> *To:* elecraft at mailman.qth.net
> *Subject:* Re: [Elecraft] Dual Receiver Tricks
>
> Over the past few years I have twice requested Elecraft include
> something like that as a software modification, but nobody (either at
> Elecraft or here on the list) seems interested in the least. Since phase
> is preserved during down conversion in a superhet circuit the software
> crunching could even be done at audio ... it isn't required to be done
> at RF.  It doesn't require the K4 either ... the K3 and K3s with the new
> synths also make it feasible.
>
> In addition to simply determining signal direction, the software would
> potentially be able to equalize volume from the two receivers (generally
> required since typically two different antennas would be used) and then
> add or subtract the two signals to peak a desired signal or null an
> unwanted one.  The equalization could be done in software while the
> phase shifting would be manual and require a repurposing of a knob.  DX
> Engineering sells a stand alone unit for over $700 that performs these
> same functions at RF, while a software mod could do the same for free
> (to us ... obviously it would take a commitment of coding resources from
> Elecraft).
>
> Elecraft has already said that they would at some indeterminate time in
> the future consider sanctioning well-chosen and trusted third party
> software developers for ancillary applications for the K4, but I'd like
> to see this capability for my K3 as well.
>
> As an aside, it would theoretically be possible to investigate arrival
> angles using two horizontally polarized antennas placed one above the
> other a known distance apart.  At the least it might even allow a user
> to discriminate between two interfering signals from the same azimuth
> but arriving at different vertical angles.
>
> 73,
> Dave   AB7E
>
>
> On 6/25/2019 8:14 AM, Dick Dickinson wrote:
> > A late model SDR Receiver (only) is said to have a soon to be released
> > software update.  I've seen a demonstration whereby using 2 antennas 
> and a
> > computer device, the unit will be able (to some degree?) determine 
> signal
> > direction.
> >
> >
> >
> > Does Elecraft have plans to develop K4D software with such 
> capabilities or
> > sanction 3rd party development of such?  Will there be other software /
> > firmware development to come with the K4D beyond that of a dual receiver
> > K3/s?
> >
> >
> >
> > Lastly, beyond control and perhaps IF output, will the K4 receiver(s) be
> > able to interface with external 'computers?'  (No, I'm not sure what 
> I mean
> > by that!)
> >
> >
> >
> >
> >
> > Kindly,
> >
> > Dick - KA5KKT
> >
> >
> >
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