Re: [TenTec] diversity receive with a pair of OmniVIs???

[Carl Moreschi <n4py3@earthlink.net>]

You do need two antennas at right angles for diversity.  You just need 
two antennas at slightly different locations.  The idea is both 
constructive and destructive fading of a signal occurs because of a 
multipath signal.  At any different point, the interference between the 
multipath signals could be a fade or a peak.  So antenna 1 could be in a 
deep fade while antenna 2 is at a peak.  So receiving on both greatly 
increases your chances that one antenna will never be in a deep fade. 
This QSB is most prominent on 80 and 160 meters where the wave lengths 
are long causing long times between fades and peaks.
Carl Moreschi N4PY
58 Hogwood Rd
Louisburg, NC 27549
www.n4py.com

On 3/12/2015 9:03 PM, Gary - AB9M wrote:
> I believe you could (or can) do diversity receive with a pair of
> OMNI-VIs (or a pair of any similar receivers which are stable and can
> track in frequency together). The other requirement is two antennas at
> right angles (in any plane) to each other, both having feed lines of the
> same electrical length to achieve space or polarization diversity.
>
> While I have seen advertisements for diversity receive using the FLEX
> 5000 and FLEX 6700 radios, I remember doing the same thing with a pair
> of Drake R4-B receivers back in the 70s. The thing I remember was that
> as a signal would start to fade on one, it would increase on the other.
> (see http://www.w8ji.com/polarization_and_diversity.htm and
> http://kc.flex-radio.com/knowledgebasearticle50386.aspx)
>
> 73 & DX,
>
> Gary - AB9M
>
> -----Original Message----- From: Barry N1EU
> Sent: Thursday, March 12, 2015 2:37 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] diversity receive with a pair of OmniVIs???
>
> Don't laugh, but this would be easy to pull off in theory with a pair of
> Corsairs driven by an external VFO. A DDS design (N4YG, G3TXQ) ideally
> would be modified to incorporate two DDS boards driving the two Corsair
> with an offset table to get the two rigs precisely aligned together.
>
> One dream of mine is to one day build a DDS vfo with integrated CAT port
> for the Corsair. Why not make it two CAT ports, coupled with the dual DDS
> and have a full blown SO2R/diversity switchable setup? ULTIMATE Corsairdom
> indeed.
>
> 73, Barry N1EU
>
> On Tue, Mar 10, 2015 at 5:03 PM, Allan Taylor <k7gt.cw@gmail.com> wrote:
>
> > I have been watching the prices of OmniVIs drop dramatically so that it
> > likely wouldn 't pay to sell them off. Also, since the Orion II is no
> > longer
> > in production with no likely follow-on top-end xcvr (at least soon,
> > anyway),
> > I wonder if there is some software scheme or such to allow a pair of
> > OmniVIs to have their VFOs lock or track and thus provide a sort of
> > diversity receive.I have read in the manual that there is some sort of
> > 'matrix' mode but am not sure what that would provide. Can someone out
> > there more knowledgeable address these questions?
> >
> > --
> > 73 Allan K7GT
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