[K3] Diversity antenna experiences?

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[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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Re: [K3] Diversity antenna experiences?

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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Re: [K3] Diversity antenna experiences?

Ken Widelitz
In reply to this post by Jim AB3CV
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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Re: [K3] Diversity antenna experiences?

ai2n
In reply to this post by Jim AB3CV
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
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

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Re: [K3] Diversity antenna experiences?

Barry N1EU
In reply to this post by Jim AB3CV
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
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Re: [K3] Diversity antenna experiences?

W0FK
In reply to this post by ai2n
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

"The difference between stupidity and genius is that
genius has its limits." Albert Einstein

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Re: [K3] Diversity antenna experiences?

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
> Sent from the Elecraft mailing list archive at Nabble.com.
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> Elecraft mailing list
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