Re: [IRCA] Some help with "large" loops?

[Brett Saylor <bsaylor@xxxxxxxxx>]

To add to Russ' information: for the loops we use at LBI, I bought 18 gauge
twin conductor speaker wire at Lowes and split the pair into a single wire
- that's small enough to fit through the eyelet at the tip of the 16'
Cabela's fishing pole (which are these:
http://www.cabelas.com/product/Cabelas-Classic-Crappie-Pole/738689.uts) and
it's not too expensive. I occasionally will have breakage issues with 18
gauge wire in high winds, however.

As Nick mentions, the Wellbrook FLG100 is a top-notch transformer/preamp -
we used one of those on our LBI Super Loop, plus another DX Engineering
RPA-1 preamp to boost the signal to 6-10 DXers' radios.

Brett Saylor
State College, PA



On Tue, Nov 18, 2014 at 4:31 PM, Russ Edmunds <wb2bjh@xxxxxxxxx> wrote:

> For our DXpeditions at Long Beach Island NJ, we use a 16' x 36'
> arrangement, using two collapsible fiberglass fishing poles from Cabela's
> Outdoor Stores ( also available on line ). I forget what they cost but I
> don't think it's that much. For 8' of height, you might do better at 18-20'
> of length.
>
> Height isn't critical, nor is sag. What seems to be most critical is the
> ratio of height to length. The size we've used seems to be close to
> optimal. Ours has the bottom wire on the ground. For using these types of
> supports, you can use moderately lightweight wire - strong enough not to
> break easily, but not enough to create wind resistance.
>
> As we split the antenna amongst 6 to 10 DX'ers, we use 2 preamps, either
> Wellbrook or another brand which is a bit less expensive although the brand
> name escapes me right now. You might get by with only one.
>
>
>
> On Tue, Nov 18, 2014 at 11:50 AM, Nick Hall-Patch <nhp@xxxxxxxx> wrote:
>
> > Nobody's jumped in yet Brian, so some quick opinions.
> >
> > - How important is the shape and symmetry of the loop; e.g. wire sag,
> > sloping ground, differing heights of the two vertical components?
> >
> > You can get away with some variation (I know I've discovered after the
> > fact that one vertical leg wasn't as tall as I thought it was) and sag,
> but
> > it doesn't hurt to aim for symmetry.
> >
> > - How important is the height above ground for the bottom wire?
> >
> > I have a Flag that is about 10 feet above the ground for the bottom wire,
> > and found not a lot of difference from one that is a foot or so above the
> > ground, at least so far as nulls are concerned.  The higher antenna may
> be
> > a bit quieter when dealing with local noise.
> >
> > - Does the type of wire matter much (within reason)?
> >
> > not that I'm aware of
> >
> > - If I want something reasonably sturdy and with the possibility of going
> > up to 20-25' height, am I looking at $100 or more for a suitable pair of
> > telescopic fiberglass poles?  I don't plan on deploying this if it's
> windy.
> >
> > I wouldn't go for height to start with, so keep it simple.  A properly
> > tensioned 1x2 x 10 or 12 feet can be sturdier than a telescoping pole.
> > Poles are great for portability or instant antennas however.
> >
> >  An amplifier can help if you think it's a bit deaf.  I really like the
> > Wellbrook FLG100, but it's pricey.
> >
> >
> > It sounds like your antenna has to be close to the house by necessity, so
> > you might be losing some of the characteristics (and getting additional
> > noise).   If you think that might be an issue, you could look into Mark
> > Connelly's Micro Super Loop:  http://www.qsl.net/wa1ion/
> > loop/car_roof_loop.htm   I don't think it has to be attached to a car,
> > hi.  (amplifier necessary)
> >
> > A remotely adjustable termination can help at least when you are getting
> a
> > feel for the antenna.   Again, Mark Connelly has suggestions.  I still
> have
> > mine remotely adjustable, as sometimes that extra couple of dB less on
> the
> > splash can bring out the DX.
> >
> >
> > best wishes,
> >
> > Nick
> >
> >
> >
> > At 07:25 18-11-14, you wrote:
> >
> >> I'm hoping to pick the brains of those of you who have experimented with
> >> various "modern" loop designs.  With limited room, poor ground
> >> conductivity, and not being able to set up something permanent, I've
> been
> >> a
> >> bit discouraged by the sizes of antennas that people are using to get
> >> nulling patterns other than a figure-eight.  However, after looking at
> >> Bruce Conti's page on the "Super Loop" (corner-terminated, corner-fed),
> I
> >> realized that this was something I could try after all.
> >>
> >> This weekend, I threw together a "portable" 8' x 25' loop using PVC pipe
> >> and wood for the two end supports.  I still need to do the termination
> and
> >> impedance matching right, but my "close enough" beta version was
> promising
> >> as far as signal strength across the BCB and noise levels, although the
> >> quality of the backside nulling wasn't as clear (the whole point of this
> >> experiment is to null out SoCal and/or northern Baja California).  This
> >> was
> >> squeezed in between the house and carport, the only practical corridor I
> >> have for something this size.  I would like the ability to have a
> support
> >> 20-25' high, mainly to get the loop more clear of structures.
> >>
> >
> >
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>
>
> --
> Russ Edmunds
> 15 mi NW Phila
> Grid FN20id
> <wb2bjh@xxxxxxxxx>
>
> AM: Modified Sony ICF2010's (2) barefoot w/whip
> FM: Yamaha T-80 & T-85, each w/ Conrad RDS Decoder;
> Onkyo T-450RDS; Tecsun PL-310 ( 2);
> modified Sony ICF2010 w/APS9B @ 15';
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-- 
N3EVB-State College PA USA
Drake R8//Icom R75//Tentec RX320//Perseus SDR//Eton E1/E5/E10/E100
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