[K3] Diversity antenna experiences?

[Jim AB3CV]

I put up an inverted L for the 160 contest and as expected my beverages did
a nice job of improving the receive performance over it. The inverted L did
a good job of spraying my 500w watts around and I'm satisfied with it as
well. Best LOTW confirmed DX so far is Ukraine. Not bad for the first few
days.

I did experience quite a bit of QSB as expected and would like to play with
diversity. My brief attempt at doing diversity with the inverted L in
combination with the beverage wasn't encouraging however. The S/N of the
inverted L in the left ear only provided a distraction trying to discern
the better S/N but fading signal in the right from the beverage.

At this point my primary interest is 160m diversity implementations. Any
suggestions based on experience with an inverted L and beverage? Any
suggestions for a second antenna other than these two that would
potentially work better when combined with the beverage?

Note: I'm on a partially wooded 1 acre lot in a HOA so big receive
structures like an 8 circle aren't possible. My beverages are BOGs for that
reason.

Thanks

jim ab3cv
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[Craig Smith]

Sounds like a fairly good experience overall, Jim.  

I'm on an even smaller (< 0.25 acre) HOA restricted lot and had an inverted L on 160 that I used in conjunction with a K9AY receive antenna.   I really liked the K9AY, as it allowed for directional switching and very good S/N ratios with a very small footprint.   Much better at RX than the inverted L.   I also had it set up for diversity but noted the same thing you did with your BOG Beverage - the K9AY was so much better I just ended up using it without diversity for RX.

One issue is that for optimal diversity reception the two antennas need to be spaced a fair distance apart in terms of wavelength.   I certainly didn't have that here (K9AY and inverted L only about 60 feet apart).   Even with your one acre, you might not have enough separation, depending on your layout.

73  Craig   AC0DS



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[Ken Widelitz]

I recently installed the new Shared Apex Loop Array from Array Solutions.
While I installed the 20' model, the 12' model has a much smaller footprint.
The 20' model works amazingly well and the specs show the 12' model doesn't
give up much.

73, Ken, K6LA / VY2TT



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[ai2n]

Hi Jim.

I also am on a small (125' square) lot, in the city.

I have been using BOGs and 14'x29' Flags, with an 80 meter inverted L base-loaded for 160.

This year I added a 20' Shared Apex Loop Array.  Yes, my antennas are too close to each other.  The SALA routinely outperforms the Flags.  Sometimes the BOGs are best for a given station, sometimes the SALA.  When I was running Stateside this weekend I would listen South and West simultaneously.  It seemed to work well.

Additionally, you may want to "float" or detune your inverted L during rx, especially if your rx antennas are close.  My tx antenna was re-radiating quite a bit of noise; floating it cured the problem.

73, Redd - AI2N

---- Jim Miller <[hidden email]> wrote:

> I put up an inverted L for the 160 contest and as expected my beverages did
> a nice job of improving the receive performance over it. The inverted L did
> a good job of spraying my 500w watts around and I'm satisfied with it as
> well. Best LOTW confirmed DX so far is Ukraine. Not bad for the first few
> days.
>
> I did experience quite a bit of QSB as expected and would like to play with
> diversity. My brief attempt at doing diversity with the inverted L in
> combination with the beverage wasn't encouraging however. The S/N of the
> inverted L in the left ear only provided a distraction trying to discern
> the better S/N but fading signal in the right from the beverage.
>
> At this point my primary interest is 160m diversity implementations. Any
> suggestions based on experience with an inverted L and beverage? Any
> suggestions for a second antenna other than these two that would
> potentially work better when combined with the beverage?
>
> Note: I'm on a partially wooded 1 acre lot in a HOA so big receive
> structures like an 8 circle aren't possible. My beverages are BOGs for that
> reason.
>
> Thanks
>
> jim ab3cv
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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[Barry N1EU]

Jim AB3CV wrote

At this point my primary interest is 160m diversity implementations. Any
suggestions based on experience with an inverted L and beverage?

Jim, the inverted L plus Beverage should be an excellent combination  while using stereo diversity.  That's exactly what I used in ARRL160.  Conditions in ARRL160 (at my QTH) unusually favored the inv L as a receiving antenna because of very low noise levels.  So this may have been a source of confusion for why the Beverage wasn't a bigger contributor to reception.

The important trick is balancing the relative rx gain levels.  You can do a pretty good job of this using band noise alone.  Generally speaking, you should expect signals in the Beverage direction to be as strong or stronger in the Beverage vs inv L and vice versa in other directions.

73, Barry N1EU

[W0FK]

Alan, how do you "float" your L? My L is relatively close to my receiving antennas, and I'd like to try that out and see if it makes a difference.

73,

Lou, W0FK

ai2n wrote

Additionally, you may want to "float" or detune your inverted L during rx, especially if your rx antennas are close.  My tx antenna was re-radiating quite a bit of noise; floating it cured the problem.

[ai2n]

I just disconnect the L from the coax center conductor AND the beta match coil using a heavy duty open frame relay.  Works for me.  Make sure the relay contacts get closed before the tx RF arrives.  I use K6XX's relay accelerator  http://members.cruzio.com/~k6xx/radio/fastrely.pdf

73, Redd  AI2N


---- W0FK <[hidden email]> wrote:

> Alan, how do you "float" your L? My L is relatively close to my receiving
> antennas, and I'd like to try that out and see if it makes a difference.
>
> 73,
>
> Lou, W0FK
>
>
> ai2n wrote
> > Additionally, you may want to "float" or detune your inverted L during rx,
> > especially if your rx antennas are close.  My tx antenna was re-radiating
> > quite a bit of noise; floating it cured the problem.
>
>
>
>
>
> -----
> St. Louis, MO
> K3 #'s 7463 and 2513, P3 #620, KX1 #1517, KX3 #0036
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-Diversity-antenna-experiences-tp7581518p7581620.html
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