LOOP SHOWDOWN - part 2 of 2

[MarkWA1ION@xxxxxxx]

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CHTN - 720 / Charlottetown, PI    
Kiwa: S-7; good readability  
RSM-105: S-4; good readability 
RSM-105 via Mini-MWT-3: S-9 + 10 dB; good readability
On all three set-ups, WRKO - 680 slop was a problem at times.

CFDR - 780 / Dartmouth, NS    
Kiwa: S-3; audio in amplifier noise  
RSM-105: S-1; in receiver noise, carrier only detectable with BFO on
RSM-105 via Mini-MWT-3: S-3.5; audio in amplifier noise
On all set-ups, WCCM - 800 slop was a problem at times.
This station is received at fair level on wire antennas via Mini-MWT-3.

WNYC - 820 / New York, NY    
Kiwa: S-8; good readability  
RSM-105: S-5; good readability
RSM-105 via Mini-MWT-3: S-9 + 10 dB; good readability

WLAM - 870 / Gorham, ME    
Kiwa: S-8; good readability  
RSM-105: S-5; good readability
RSM-105 via Mini-MWT-3: S-9 + 10 dB; good readability

CKBW - 1000 / Bridgewater, NS    
Kiwa: S-5.5; good readability, slight amp noise  
RSM-105: S-3.5; fair to good readability, slight receiver noise
RSM-105 via Mini-MWT-3: S-8.5; good readability, negligible noise

WINS - 1010 / New York, NY    
Kiwa: S-8; good readability  
RSM-105: S-5; good readability
RSM-105 via Mini-MWT-3: S-9 + 10 dB; good readability

KYW - 1060 / Philadelphia, PA    
Kiwa: S-2; carrier in amp noise  
RSM-105: S-1 (not moving meter); carrier only detectable with BFO on
RSM-105 via Mini-MWT-3: S-3; bits of apparent talk, in amp noise

CBA - 1070 / Moncton - Sackville, NB    
Kiwa: S-6; good readability  
RSM-105: S-2; fair readability with receiver noise
RSM-105 via Mini-MWT-3: S-8; good readability
The Plattsburgh, NY co-channel station was audible in the background:
its strength was about 10 dB weaker than CBA; it could be isolated 
from CBA by nulling northeast / peaking northwest.

WJJF - 1180 / Hope Valley, RI    
Kiwa: S-7; good readability  
RSM-105: S-2.5; fair to good readability over receiver noise
RSM-105 via Mini-MWT-3: S-9 + 5 dB; good readability

WLIB - 1190 / New York, NY    
Kiwa: S-7; good readability  
RSM-105: S-2.5; fair to good readability
RSM-105 via Mini-MWT-3: S-9 + 5 dB; good readability
There was moderate slop at times from WKOX - 1200.  The higher 
Q of the Kiwa gave it an edge over the unamplified RSM-105.

WGMP - 1210 / Philadelphia, PA    
Kiwa: S-4; with audio but noisy, WKOX slop a problem until regen. tweaked  
RSM-105: S-1.5; near receiver noise floor, bits of audio heard
RSM-105 via Mini-MWT-3: S-8; better readability than Kiwa

WEZS - 1350 / Laconia, NH over WINY - 1350 / Putnam, CT    
Kiwa: S-9; good readability  
RSM-105: S-6; good readability, but WLYN - 1360 slop worse because 
of lower Q than Kiwa.
RSM-105 via Mini-MWT-3: S-9 + 15 dB; good readability
6-dB-weaker WINY could be isolated by nulling north / peaking west.

WDJZ - 1530 / Bridgeport, CT    
Kiwa: S-7; fair to good readability (some WNRB - 1510 slop) 
RSM-105: S-2.5; fair readability with slop and receiver noise
RSM-105 via Mini-MWT-3: S-8.5; fair to good readability through WNRB slop

WLIM - 1580 / Patchogue, NY    
Kiwa: S-5; fair readability  
RSM-105: S-1.5; poor to fair readability with receiver noise
RSM-105 via Mini-MWT-3: S-7; fair readability
CBJ (Chicoutimi, PQ) and another signal (NJ ?) were audible in the
background.  Multiple station slop (WNSH - 1570, WSMN - 1590, and 
WUNR - 1600) was a problem on each set-up some of the time.


Home "reference test" on WZNN - 930 / Rochester, NH (not a weak station)
100 ft. / 30 m wire: S-8.5
100 ft. / 30 m wire via Mini-MWT-3: S-9 + 35 dB
Quantum: S-9 + 15 dB
Kiwa: S-9 + 12 dB
RSM-105: S-7.5
RSM-105 via Mini-MWT-3: S9 + 20 dB
Readability in all cases was very good.  


Conclusions: The best loop choice for a given DXer will be determined
by the receiver, location, and type of DXing to be done.  Sensitivity
is not critical for night use, except in auroral conditions or at
exceedingly remote sites such as the Australian "outback".  Strong
signal handling is very important at an urban site, but less so in
the country.  The physical size of the loop is important to those
who take it "in the field" or who have very small DX "shack" rooms.
Good nulling is important to most of us, except perhaps for the
steel-frame apartment dweller who can only receive stations with
the loop pressed up against a window.  And a not-insignificant
factor is price.  Some time ago, Elliot Straus contemplated the
question "Is a Kiwa worth more than twice as much as a Quantum ?".
For some the answer is "yes", for others "no".  The RSM-105 is
about twice the price of a Quantum, and a bit less than the Kiwa.
For city DXers, the RSM-105 will be the hands-down choice.  It is
"bulletproof".  Active loops are much more likely to generate 
intermodulation distortion products in the urban environment.
Those with less-than-ultimate receivers may want to use a low-noise /
high-Q preamplifier (such as the Mini-MWT-3) between the RSM-105's
output and their receiver inputs.  For DXers who like parking at a 
beach, pier, or mountaintop for prime loggings, the Kiwa - with 
its remote tuning - wins.  For the business or vacation traveller, 
the Quantum fits right in a suitcase when it's time to catch a flight 
somewhere.  Some DXers will forego loops entirely and opt for phased
wires.  Those lucky enough to have land for Beverages will find them
hard to beat.  

As no one screwdriver can be used for every kind of screw, no single
type of antenna is best for every DX situation.  This article's 
discussions and test results should serve as a guide to allow DXers 
to make wise reception-improving choices for their specific 
circumstances.  I hope that this article stimulates others to
do similar testing and to publicize their findings.
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