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Diversity Receive

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Jim Cox

Diversity Receive

What kind of antennas are most using for HF diversity receive? I wonder how the small active antenna produced by Clifton Labs would work as a diversity antenna on the HF bands. I have a K9AY loop that works well on 160 and 80 meters but its dead on other bands..

Jim K4JAF

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Bob Naumann W5OV

Re: Diversity Receive

Jim,

Turn off the preamp in your K9AY system and you can use it on other bands.

The preamp includes a bandpass filter for 160 and 80. You should have
usable sensitivity on other bands without the preamp.

73,

Bob W5OV

> What kind of antennas are most using for HF diversity receive? I wonder
> how the small active antenna produced by Clifton Labs would work as a
> diversity antenna on the HF bands. I have a K9AY loop that works well on
> 160 and 80 meters but its dead on other bands..
>
> Jim K4JAF
>
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Craig Smith

Re: Diversity Receive

In reply to this post by Jim Cox

I have the Clifton active whip as well as a K9AY, and use both with
diversity RX. The Clifton is a fine choice as an alternative RX and
diversity antenna. Note that both the Clifton and K9AY are vertically
polarized. Ideally your diversity antennas should have opposite
polarization and adequate physical separation. I'm in a cramped location
here and the most separation between any two antennas is about 70 ft, so far
from ideal, especially on the low bands. When I use my temporary doublet
for a Xmit antenna, I normally use that in conjunction with either the
Clifton or the K9AY for diversity. When I use my Xmit vertical, I typically
use the Clifton and the K9AY together for diversity RX. In spite of the
less than optimal arrangements here, I still find that diversity RX is quite
worthwhile, and enjoy the way it is implemented in the K3.

73 Craig AC0DS

<> I wonder how the
<> small active antenna produced by Clifton Labs would work as a diversity
antenna on the
<> HF bands. I have a K9AY loop that works well on 160 and 80 meters but
its dead on
<> other bands..

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Guy, K2AV

Re: Diversity Receive

On 40 meters and up, I use transmitting antennas at 90 degree offset. 90
degree offset dipoles on 40 deliver a surprising separation on weak dx
signals who don't have the big towers and beams. At high incoming angles
the offset dipoles separate the signals by incoming polarization.

73, Guy.

On Thu, Sep 30, 2010 at 11:55 AM, Craig D. Smith <[hidden email]>wrote:

> I have the Clifton active whip as well as a K9AY, and use both with
> diversity RX. The Clifton is a fine choice as an alternative RX and
> diversity antenna. Note that both the Clifton and K9AY are vertically
> polarized. Ideally your diversity antennas should have opposite
> polarization and adequate physical separation. I'm in a cramped location
> here and the most separation between any two antennas is about 70 ft, so
> far
> from ideal, especially on the low bands. When I use my temporary doublet
> for a Xmit antenna, I normally use that in conjunction with either the
> Clifton or the K9AY for diversity. When I use my Xmit vertical, I
> typically
> use the Clifton and the K9AY together for diversity RX. In spite of the
> less than optimal arrangements here, I still find that diversity RX is
> quite
> worthwhile, and enjoy the way it is implemented in the K3.
>
> 73 Craig AC0DS
>
> <> I wonder how the
> <> small active antenna produced by Clifton Labs would work as a diversity
> antenna on the
> <> HF bands. I have a K9AY loop that works well on 160 and 80 meters but
> its dead on
> <> other bands..
>
> ______________________________________________________________
> 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
>

David Cutter

Re: Diversity Receive

In reply to this post by Craig Smith

Craig

When you say " I typically use the Clifton and the K9AY together for
diversity RX" how do you do that?

David
G3UNA

Vic K2VCO

Re: Diversity Receive

In reply to this post by Jim Cox

On 9/30/2010 8:39 AM, Jim Cox wrote:
> What kind of antennas are most using for HF diversity receive? I wonder how the small
> active antenna produced by Clifton Labs would work as a diversity antenna on the HF
> bands. I have a K9AY loop that works well on 160 and 80 meters but its dead on other
> bands..

I have very little room for antennas, so I use polarization diversity. I have a short
groundplane (originally intended for 17 meters) which I use for diversity together with 40
and 80 meter dipoles. I use the K3's preamp with the groundplane, and normally use the
attenuator on the 80m dipole. This is a big help with weak cw signals on 40m, less so (but
still useful) on 80.

On 20m I have a beam, and since the signal is always much better on the beam, there's no
advantage from diversity. Sometimes it is useful to check if I'm hearing a signal via long
path without rotating the beam.

On 160m I have a small ferrite loop which I use for diversity together with my
transmitting antenna, a vertical. I have an external preamp for the loop and I use the K3
preamp too. I also use the attenuator on the vertical. It helps a little, but there are
lots of better 160m receiving antennas like the K9AY and Beverage.
--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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Edward R Cole

Re: Diversity Receive

In reply to this post by Jim Cox

Good topic and timely for me.

I have the K3/10 with dual-Rx and no KAT-3. I use an inverted-L for
600m (495.6 KHz) and plan to make a rotatable shielded loop antenna
for alternate Rx. Best location is a corner of our back deck but
this is nearly underneath the horizontal wires of the inverted-L
(43x130 foot). There may be some interaction between the two antenna
(1/4 WL at 500-KHz is 930-foot). I may configure the invert-L for
160m later this fall when I have the 300w PA QRV.

I could configure for diversity Rx, I think. The inverted-L is
connected to the XVT Rx&Tx connectors since the K3 is run in
TEST-mode on this frequency (actually, two coax lines connect to the
600m xmtr where there is a T/R relay that connects to the
inverted-L). But normally the aux-Rx would be connected to the aux
antenna jack. Since this is outside normal ham freq., the KBPF-3 is used.

Anyone see any problems with what I propose? If diversity cannot be
done then switching between Rx is adequate for selecting antennas. I
haven't played with diversity reception, so far.

73, Ed - KL7UW, WD2XSH/45
======================================
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Craig Smith

Re: Diversity Receive

In reply to this post by David Cutter

I connect the K9AY to the K3 "RX in" and the Clifton to the SUB RX "AUX in".
This will give you K9AY in left ear and active whip in right when you select
"RX ANT".
I also have a switch to select either the K9AY or the Clifton for the SUB RX
"AUX in" when I'm listening on the Xmit antenna. The K9AY is fed thru a 3
db splitter to both the "RX in" and the "AUX in" selection switch.

73 Craig AC0DS

<> When you say " I typically use the Clifton and the K9AY together for
<> diversity RX" how do you do that?

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