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 Public Gallery | Home > Arts and Crafts Next 15 
Arts and Crafts
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Hi-VHF Hourglass Loop
1. Hi-VHF Hourglass Loop  (30 Nov 2012)
Hi-VHF Hourglass Loop analyzed using 4nec2 after finding "best" dimensions using nikiml's Optimization
Scripts.  Based on UHF Hourglass Loop posted by oneolddude in www.digitalhome.ca forum:
1/4-in O.D. Elements and Reflector Rods.

NO Reflector Rods (Optimized H=41.75-in, W=34.5-in & Feedpoint Gap=2.5-in):
Ch7-13 Raw Gain = 5.3-6.1 with Excellent SWR under 1.6 (using Quarter-inch Copper Tubing).
Provides about 4 dBi Raw Gain on Ch2-6 and FM Band, but SWR is excessive.
Also provides some Raw Gain with acceptable SWR in UHF Band, but only over mid-band frequencies.

Charts assume Quarter-Inch-Copper, e.g. Tubing or RG-59 braid shield (no need to strip insulation).
Much smaller size AWG12 wire has NO effect on Gain and only increases SWR to 2.0,
so feel free to use even smaller wire sizes.

Add 15 Reflector Rods (Optimized Width, Rod-Rod Separation & Separation from Hourglass):
Ch7-13 Raw Gain = 9.7-10.05 dBi with SWR under 3.1 (using Quarter-inch Copper Tubing).  
Reflector Total Height = 68-in x Width = 56.5-in.
Excellent Front/Rear (hemisphere) Ratio = 32-34 dB with Front/Back (toward 270-deg) = 20 dB.
Provides some Raw Gain on Ch2-6 and FM Band, but directed to the REAR and SWR is excessive.
Not suitable for UHF Band: poor SWR & Gain toward Diagonals.

With 15-RR, provides Gain nearly as much as Winegard YA-1713, except sidelobe nulls moved
to sides and consistently EXCELLENT F/B and F/R Ratios.

EDIT (4Jun2013): Added Hourglass with 11 Reflector Rods and with 7 Reflector Rods to illustrate
how much reduction to expect in Gain and F/R Ratio.  Also note that Reflector Height and Width are
significantly smaller.

EDIT (6Jun2013): Added Comparison Chart showing improvement in Raw Gain & F/R Ratio with more RRs.

EDIT (14Dec2014): Added 5RR and 3RR versions.
2438 Visits
70 Images
Linked Album
UHF Vertical 6-Bay Bowtie - NO Refl
2. UHF Vertical 6-Bay Bowtie - NO Refl  (11 Dec 2014)
UHF Vertical Vertical 6-Bay Bowtie (FF6) with NO Reflector analyzed using 4nec2 after finding best Dimensions
using nikiml's Python Optimization Scripts.
62 Visits
18 Images
Linked Album
3. Matt  (12/07/2014)
108 Visits
2 Images
Linked Album
4. Wheel Chairs 
0 Visits
0 Images
Linked Album
5. Clocks  
130 Visits
4 Images
Linked Album
6. Tools 
122 Visits
14 Images
Linked Album
7. mcsqg-march  (12/1/14)
Will be making a St. Patrick's day block for March.
This block has appliqué technique.
The alternate block will be from quilterscache.com/four winds
This is a pieced block.
90 Visits
9 Images
Linked Album
8. uhf4bayhourglassloopsnorefl  (28 Nov 2014)
UHF 3-Bay Hourglass-Loop (NO Reflector) analyzed using 4nec2 after determining best Dimensions using nikiml's Python Optimization Scripts.
126 Visits
60 Images
Linked Album
Installation 11/2014
9. Installation 11/2014  (11/19/2014)
152 Visits
15 Images
Linked Album
UHF 2-Bay Hourglass-Loops - NO Refl
10. UHF 2-Bay Hourglass-Loops - NO Refl  (19 Nov 2014)
UHF 2-Bay Hourglass-Loops analyzed using 4nec2.

See analysis for Vertical Stacked Hourglass-Loops:
180 Visits
42 Images
Linked Album
UHF 3-Bay Hourglass-Loops - NO Refl
11. UHF 3-Bay Hourglass-Loops - NO Refl  (19 Nov 2014)
UHF 3-Bay Hourglass-Loops (NO Reflector) analyzed using 4nec2.

Multiple versions were analyzed with different methods for Combining Antennas:

a) Three EX Statements, emulating a PERFECT 3-Way Combiner.

b) Two "Shortest Path" Feedlines, SAME size as Hourglass Center Wire.

c) Two "Shortest Path" Feedlines, DIFFERENT size as Hourglass Center Wire.

156 Visits
93 Images
Linked Album
MCSQG  january
12. MCSQG  january  (11/18)
I seen a different way of doing the trapunto. It is easier and faster but you will not see the effect until it is quilted.
146 Visits
6 Images
Linked Album
HP Drama Club Ten Year Anniversary
13. HP Drama Club Ten Year Anniversary  (November 10, 2014)
336 Visits
135 Images
Linked Album
MCSQG February
14. MCSQG February   (11/1/14)
Block of the month for February
techniques appliqué, chenille (optional)
162 Visits
7 Images
Linked Album
Quilt show 2013
15. Quilt show 2013  (2013)
Bloomington quilt show
156 Visits
26 Images
Linked Album
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