Re: [IRCA] Slinky EWEs vs Regular Wire (WAS: is this a good deal for BOG Wire)

[Guy Atkins <dx@xxxxxxxxxxxxx>]

>
> Hi Dave,
>

Kevin Schanilec on Bainbridge Island, WA recently did some careful tests
between his Slinky EWE and an identical one made with normal wire. The
results really surprised him...here's what he said:

-----------

I am drinking a strong cup of decaf to steady my nerves because, as
amazing as it might sounds, the wire loop won!

For bare signal, the Slinky version never trailed and was perhaps 3-4 dB
stronger on various frequencies.  This is not surprising, since the two
Slinkys used comprise about 110 feet of wire, while the wire version only
has 38 feet of wire; theory says that it should be a few dB better.

However, the signal was always at least as good on the wire version, and
often noticeably better, especially on marginal signals.  My ears time and
time again told me that the difference is that the wire version picks up
much less local electromagnetic noise - it simply gives a better signal.
For example, there was a weak station on 1270 that was struggling to stay
above the neighborhood QRM on the Slinky, but had readable audio on the
wire.  Unless a station was doing fairly well, the wire gave the better
signal.

This is no fluke.  A couple weeks ago, when I first started this Super
Loop nonsense, I wound two identical 16:1 matching baluns, and did the
same testing when weak TA's were coming in.  The hets and signals on the
wire were often stronger than on the Slinky, again attesting to the fact
that the SNR on the wire is better.  I decided to wait to get the FLG-100
to make sure my kludged baluns weren't influencing the results, and sure
enough the wire won again.

What's going on here? Gil steered me to the following site:
http://www.w8ji.com/slinky_and_loaded_beverages.htm
which includes a discussion of the fact that a Slinky, unless stretched
VERY long, will have at least 4-6 times more conductor length than actual
physical length - too many "turns per foot".  Too much coiled-up conductor
means that signal wants to fire backwards, towards the feed point.  I'm no
physics guru like the web site's author appears to be, but it seems like a
possible explanation.  This could mean that my PVC version could be
hand-wound with 76 feet of wire in a gradual spiral to get 2-3 more dB,
which I may just try.

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

Dave, I hope this is helpful before you go to the trouble to build a Slinky
EWE!

73,

Guy Atkins
Puyallup, WA
fivebelow.squarespace.com


>
> -----Original Message-----
> From: HASCALL, DAVID CIV DFAS [mailto:DAVID.HASCALL@xxxxxxxx]
> Sent: Tuesday, December 22, 2009 11:35 AM
> To: Bill Nollman; amdx@xxxxxxxxxxxxxxxx; irca@xxxxxxxxxxxxxxxx
> Subject: RE: [Amdx] Is this a good deal (and good wire) for BOG wire?
>
> Likewise I'm really fascinated with EWE's to include David Hamilton's
> Slinky version.  Unfortunately they may be too quiet for use here and
> may need an amp.  Wonder if one could put a EWE on the ground?
>
> Dave
>
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