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 Public Gallery | Home > Arts and Crafts Next 15 
Arts and Crafts
1 - 15 of 673 Total. Shared
cards
1. cards 
Home made cards, personalised candles and other home made nick knacks.
30 Visits
14 Images
Linked Album
wertp
Vintage Jools Take 2
2. Vintage Jools Take 2 
546 Visits
66 Images
Linked Album
scanjpg1
3. Performing arts center 
5 Visits
0 Images
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kmurphyimages
4. Country drive 4 
6 Visits
0 Images
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kmurphyimages
Antennacraft G-1483 Hoverman Type 2
5. Antennacraft G-1483 Hoverman Type 2  (4 Apr 2013)
Antennacraft G-1483 variation of (SBGH) Hoverman Type 2 (With 4 Reflector Rods) analyzed using 4nec2.

Dimensions per EscapeVelocity, 4nec2 file by <300ohm> as modified by holl_ands: added FR & RP Cards
to facilitate repeatable runs.
3301 Visits
15 Images
Linked Album
holl_ands
Rocking chair
6. Rocking chair  
240 Visits
2 Images
Linked Album
bloodandwhiskeydesign
Army boots
7. Army boots 
252 Visits
3 Images
Linked Album
bloodandwhiskeydesign
UHF Free-Form 4-Bay + DblAnglRefl - OPT
8. UHF Free-Form 4-Bay + DblAnglRefl - OPT  (2 Nov 2013)
UHF Free-Form 4-Bay (FF4) Bowtie Antennas with various sized Variable Double Angle Reflectors (VDAR)
analyzed using 4nec2.  Essentially ALL dimensions were Optimized using nikiml's Python Scripts,
including the Angle of the Reflector's outer "wings".

a) FF4 + Reflector = 40"x36" (unfolded), same as mclapp's M4 for backfits & comparison purposes,
but Reflector is Swept Forward 4.375-in vice 2.5-in.  Elements and Feedline are AWG10.

When I changed to AWG8 (w/o reoptimizing), FF4 Gain = 14.3 to 15.3 to 14.8 to 15.6 dBi,
with Gain on 470 MHz increasing 0.3 dB, but only 0.1 dB on other freqs.
Compare to M4 (10.0"x9.5") Gain =  13.8 to 15.8 to 15.0 dBi and M4 (9.5"x9.0") Gain = 13.3 to 16.0 dBi.
So FF4 Gain increased as much as 1 dB on 470 MHz, with higher Gain on low to mid-band channels
and about the same on the higher channels, with somewhat lower F/B & F/R Ratios (probably
needs a larger Reflector) and same High Gain in Hi-VHF Band:

UHF FF4 Raw Gain = 15.1 dBi +/- 0.4 dB, dropping to 14.0 dBi on 470 MHz, F/B & F/R Ratio Min = 14.8 dB
[GOOD] and SWR (300-ohms) under 1.8.
Hi-VHF Raw Gain = 8.1 dBi, F/B & F/R Ratio Min = 19 dB [EXCL] and SWR = 16.8 to 15.7 [Excessive].

SUMMARY OF DIMENSIONS FROM 4nec2 FILE (In inches, rounded to nearest 1/8-in):
Rbow=0.051            ' Radius of Bowtie Elements (AWG10)
Rfeed=0.051           ' Radius of Feedlines (AWG10)
Hop=1.0              ' X-Coord Separation of Feedlines at Crossover
ZBowII=12.0    ' From center of INNER bowtie to center of INNER bowtie, Optimizer found 11.99499
ZBowOI=11.0    ' From center of INNER bowtie to center of OUTER bowtie, Optimizer found 10.91547
BowLeni=11.5    ' INNER Bow Whisker Length (lose some in bend), Optimizer found 11.59459
BowLeno=12.0    ' OUTER Bow Whisker Length (lose some in bend), Optimizer found 11.95864
BSi=1.5            ' INNER Bow Forward Sweep distance at tip of the Whisker, Optimizer found 1.557153
BSo=5.75          ' OUTER Bow Forward Sweep distance at tip of the Whisker, Optimizer found 5.78872
TineSepi=7.375    ' INNER Bow Tine Separation, Optimizer found 7.344971
TineSepo=6.5    ' OUTER Bow Tine Separation, Optimizer found 6.513835
FS=1.75            ' Separation between two FEEDLINE wires, Optimizer found 1.773704
ZCross=2.625      ' From center of Feedline Cross-Over to center of OUTER Bowtie, Optimizer found 2.68731

##################################################################
b) FF4 + TALLER Reflector = 48"x36" unfolded), Reflector is Swept Forward 3.375-in vice 2.5-in.
Elements and Feedline are AWG10.  Outer Bowties are now much smaller, at SAME Angle as Inner.
Raw Gain increased 0.3 dB on 470 MHz,  1.6 dB more on 698 MHz and eliminated the mid-Band Gain Dip
found in the above AWG10 40x36-in Reflector.

UHF Raw Gain = 14.6 (470 MHz) to 16.2 (674 MHz) peaking at 17.1 dBi (698 MHz),
UHF F/B & F/R Ratio Min = 14.8 dB [GOOD] and SWR (300-ohms) under 2.1.
Hi-VHF Raw Gain = 10.8 to 8.3 dBi, F/B & F/R Ratio Min = 10.9 dB [FAIR] and SWR (300-ohms) = 34 to 23 (Excessive).

SUMMARY OF DIMENSIONS FROM 4nec2 FILE (In inches, rounded to nearest 1/8-in):
Rbow=0.051        ' Radius of Bowtie Wires
Rfeed=0.051       ' Radius of Feedline Wires
Hop=1.0              ' Wire Separation at the Feedline Crossover
ZBowII=12.0        ' From center of INNER bowtie to center of INNER Bowtie, Optimizer found 11.99729
ZBowOI=10.675     ' From center of INNER Bowtie to center of OUTER Bowtie, Optimizer found 10.67465
BowLeni=12.875     ' INNER Bow Whisker Length (lose some in bend), Optimizer found 12.86343
BowLeno=8.125     ' OUTER Bow Whisker Length (lose some in bend), Optimizer found 8.124315
BSi=3.5            ' INNER Bow Forward Sweep distance at tip of the Whisker, Optimizer found 3.496068
BSo=2.25          ' OUTER Bow Forward Sweep distance at tip of the Whisker, Optimizer found 2.273594
TineSepi=6.75     ' INNER Bow Tine Separation, Optimizer found 6.813349
TineSepo=3.875     ' OUTER Bow Tine Separation, Optimizer found 3.875966
FS=2.875            ' Separation between two FEEDLINE wires, Optimizer found 2.82885
ZCross=2.375       ' From center of Feedline Cross-Over to center of OUTER Bowtie, Optimizer found 2.406892

##################################################################
c) FF4 with a TALLER and WIDER Reflector alternative is T.B.D.
3943 Visits
54 Images
Linked Album
holl_ands
UHF HD Horizon X10 Two Slot Antenna
9. UHF HD Horizon X10 Two Slot Antenna  (7 Nov 2015)
UHF HD Horizon X10 Two Unequal Slot Antenna from Solid Signal analyzed using 4nec2.  Dimensions derived from a posted
Photo of the Front Panel (compared to Mfr's HxW) and (since a measurement was not available) performance was
calculated for THREE values for Reflector Separation from Front Panel....which is NOT critical for 3.5 to 4.5-inches.
763 Visits
17 Images
Linked Album
holl_ands
Bj
10. Bj 
Hope u Will enjoy it <3
929 Visits
2 Images
Linked Album
eriksnyder
UHF 4-El-Pair FLAT-Enh1 LPDA - OPT
11. UHF 4-El-Pair FLAT-Enh1 LPDA - OPT  (15 Aug 2015)
UHF 4-Element-Pair Flat+Enhanced-Element-1 LPDA (Log Periodic Dipole Array) analyzed
using 4nec2 after determining Dimensions using nikiml's Python Optimization Scripts.
837 Visits
21 Images
Linked Album
holl_ands
cm4228hdnoreflHHH
12. cm4228hdnoreflHHH  (20 Oct 2015)
CM4228HD with NO Reflector and HHH (Holl_ands Horizontal Harness) analyzed using 4nec2, SAME version as OPTIMIZED earlier with 16 Reflector Rods.

UHF Raw Gain = 11.7 to 13.8 dBi, F/B & F/R Ratio = 1.7 to 0.5 dB and SWR (300-ohms) = 2.8 (Good).
Hi-VHF Raw Gain = 3.5 to 5.0 dBi, F/B & F/R Ratio = 1.2 to 1.0 dB and SWR (300-ohms) = 3.3 to 4.0 (a bit High).
2439 Visits
21 Images
Linked Album
holl_ands
UHF Vertical Folded Dipole OMNI
13. UHF Vertical Folded Dipole OMNI  (29 Oct 2015)
UHF Vertical Folded Dipole analyzed using 4nec2.  It provides a TRUE OMNI-Directional
Azimuthal Pattern, but ONLY for Vertical and Circular/Elliptical Polarized signals.

Fol. analysis assumed fol. Dimensions:
L2=9.25          ' Folded Dipole Overall Element Length
FW=1.0           ' Distance between Folded Dipole Elements
RACT=0.125    ' Radius (inches) for Driven Element is 1/4-in O.D. Copper Tubing
GAP=0.5      ' Balun FeedPoint Gap Size

Dimensions for other Diameter Tubing and it's effect on SWR can be found in the analysis for
UHF Folded Dipole for Horizontal Polarized signals:
http://imageevent.com/holl_ands/loops/folded
Note that it's the SAME Antenna, except oriented Vertical or Horizontally.
666 Visits
12 Images
Linked Album
holl_ands
Hi-VHF Vertical Folded Dipole OMNI
14. Hi-VHF Vertical Folded Dipole OMNI  (29Oct2015)
Hi-VHF Vertical Folded Dipole analyzed using 4nec2.  It provides a TRUE OMNI-Directional Azimuthal Pattern.

Fol. analysis assumed fol. Dimensions:
L2=27.5          ' Folded Dipole Overall Element Length
FW=2.0           ' Distance between Folded Dipole Elements
RACT=0.2845  ' Radius (inches) for Driven Element is Standard Type M 1/2-in O.D. Copper Tubing

Dimensions for other Diameter Tubing can be found in Analysis of Hi-VHF Folded Dipole for Horizontal Polarized signals:
656 Visits
9 Images
Linked Album
holl_ands
UHF FF3 3-Bay Bowtie - NO Reflector
15. UHF FF3 3-Bay Bowtie - NO Reflector  (21 Oct 2015)
UHF Free-Form 3-Bay (FF3) analyzed using 4nec2 after determining Dimensions using
nikiml's Python Optimization scripts.

Three alternative interconnection Topographies were determined to be of interest for further
investigation (starting with the BEST).  Nearly ALL Bowtie Parameters were allowed to be
INDEPENDENTLY varied in determining the fol. three versions of the FF3 (Free-Form 3-Bay Bowtie):

Note that Gain Charts are for TOTAL (Horiz. + Vert.) Gain.  Azimuthal Charts show that
there is lower, but significant Vertical Gain to the SIDES of the Antenna.

a) Remove Top Bowtie from FF4 (so Offset Feedpoint) and Re-Optimize:

UHF Raw Gain = 8.6 to 11.4 dBi and SWR (300-ohms) Under 2.7 is Good.
Hi-VHF Raw Gain = 2.4 to 3.0 dBi and SWR (300-ohms) = 3.9 to 6.3 is Higher than Desired.

b) Move Feedpoint to Inner Bowtie with Crossover Feedlines to each Outer Bowtie, which
are presumably needed to ensure all three signals are In-Phase at the Feedpoint:

UHF Raw Gain = 8.1 to 10.1 dBi and SWR (300-ohms) Under 2.6 is Good.
Hi-VHF Raw Gain = 2.6 to 2.9 dBi and SWR (300-ohms) = 9.4 to 2.1 is Excessive on Ch7-11.

c) Offset Feedpoint (like a), but with Straight (NO Crossover) Feedlines to each Outer Bowtie:

UHF Raw Gain = 7.1 to 9.4 to 9.1 to 10.7 dBi and SWR (300-ohms) Under 3.1 is a Bit Higher then Desired.
Hi-VHF Raw Gain = 2.1 to 2.6 dBi and SWR (300-ohms) = 7.8 to 6.4
is Excessive.
953 Visits
87 Images
Linked Album
holl_ands
 
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