[Elecraft] KRX3 vs APF on weak signals ??

[Edward R. Cole]

Whichever works better or BOTH if that works better.
They do different things so I don't think you can answer the 
questions which is better.

I think you are trying to justify why to buy the KRX3.  And the 
answer is a question (sorry):  What is your intention for its 
use?  You stated an interest in:
1)  160m
2)  Weak/fading CW

APF works pretty nice in peaking weak CW (and its free with the K3).
But my understanding of 160m (not QRV there - yet) is that using a 
low-noise reception antenna in diversity mode can make a significant 
improvement in fading signals.  Ideally (on 160m) that would be use 
of a long wire like a Beverage or smaller low-noise antenna like 
Pendant (but this depends a lot on how much real estate you have).

On 600m as WD2XSH/45, I tried a 930-foot Beverage-on-Ground (BOG) and 
it did not work as well as my transmitting antenna which is a 43-foot 
vertical by 130-foot inverted-L.  The signals with the Inv-L were 
20-dB stronger (farthest Rx DX from Alaska is Buffalo, NY).  The 
Beverage is moot as my neighbor removed it when he needed access 
across where it lay (I had it run along side his private airstrip).

My next attempt for Rx antenna will be a shielded 6-foot diameter 
loop (rotatable) with preamp.  (600m DX season is Oct. - Mar.)  I run 
100w RF output on 495-KHz to the base-loaded Inv-L with about 0.8% 
antenna efficiency (hard to make a 1/4 WL vertical at 600meters - 492 
foot).  My 4.15w ERP signal has been heard in Vancouver, BC about 
1300 miles.  (lots of info on my website)

73, Ed - KL7UW
K3/10 with KRX3

------------------------------

Message: 21
Date: Tue, 12 Jul 2011 19:39:42 -0700 (PDT)
From: callen1155 <callen1155 at yahoo.com>
Subject: Re: [Elecraft] KRX3 vs APF on weak signals ??
To: elecraft at mailman.qth.net
Message-ID: <1310524782325-6577528.post at n2.nabble.com>
Content-Type: text/plain; charset=us-ascii

Thanks for the responses but I'm at a loss as to why the question is
confusing. I'm trying to determine the most efficient method to hear
weak/fading cw signals.

I have read on here many times where folks brag on the 2nd receivers'
ability to overcome fading band conditions via diversity receive using
complementing antennas. I have read and experienced the benefit of APF under
those same band conditions as well.

I understand diversity receive and APF go about it two totally different
ways but the end result is an improved ability to hear weak/fading signals.

My question is simply, under weak/fading band conditions when you're
straining to copy the cw sig (assuming you have both APF and diversity
receive to choose from), which would you choose to improve your copy and
make the contact?

thanks again.
chuck




73, Ed - KL7UW, WD2XSH/45
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