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Discussion Starter #1
ljhavener mentioned that the Kosmic SuperQuad with a loop gives increased VHF gain when the loop has discontinuities.

4nec2 gives this warning.

Code:
Warn.: volumes for Wires 38 (tag 40) and 40 (tag 42) are intersecting.
Warn.: volumes for Wires 38 (tag 40) and 41 (tag 43) are intersecting.
Warn.: volumes for Wires 39 (tag 41) and 40 (tag 42) are intersecting.
Warn.: volumes for Wires 39 (tag 41) and 41 (tag 43) are intersecting.

The increase VHF gain because of discontinuities seems too good to be true.

Is 4nec2 giving me a error on the VHF gain?

Here is the nec code


CM Simple SOURCE Wire. Modeled without Autoseg. Autosegment(15) can be used.
CM Source wire sized to be half way between Hi-VHF and UHF
CM Antenna can be built without reflectors. Remove wire 42-50(Tag 51-59) and
CM set Rsrc to 0.0499 AGT=1.0 UHF(540)=0.589 & HiVHF(198)=0.0409 - No Reflectors
CE
SY w1seg=1, w1x1=0, w1y1=0.754179, w1rad=0.046336
GW 1 w1seg w1x1 -w1y1 w1x1 w1x1 w1y1 w1x1 w1rad
SY w2seg=7, w2y1=10.93268, w2z1=7.391532, w2z2=5.816288, w2rad=0.060586
GW 4 w2seg w1x1 w2y1 w2z1 w1x1 w1y1 w2z2 w2rad
SY w3z1=4.241043
GW 5 w2seg w1x1 w2y1 w3z1 w1x1 w1y1 w2z2 w2rad
GW 6 w2seg w1x1 -w1y1 w2z2 w1x1 -w2y1 w2z1 w2rad
GW 7 w2seg w1x1 -w1y1 w2z2 w1x1 -w2y1 w3z1 w2rad
SY w6z1=7.391533
GW 8 w2seg w1x1 w2y1 -w6z1 w1x1 w1y1 -w2z2 w2rad
GW 9 w2seg w1x1 w2y1 -w3z1 w1x1 w1y1 -w2z2 w2rad
GW 10 w2seg w1x1 -w1y1 -w2z2 w1x1 -w2y1 -w6z1 w2rad
GW 11 w2seg w1x1 -w1y1 -w2z2 w1x1 -w2y1 -w3z1 w2rad
SY w10z1=19.02411, w10z2=17.44886
GW 12 w2seg w1x1 w2y1 w10z1 w1x1 w1y1 w10z2 w2rad
SY w11z1=15.87362
GW 13 w2seg w1x1 w2y1 w11z1 w1x1 w1y1 w10z2 w2rad
GW 14 w2seg w1x1 -w1y1 w10z2 w1x1 -w2y1 w10z1 w2rad
GW 15 w2seg w1x1 -w1y1 w10z2 w1x1 -w2y1 w11z1 w2rad
GW 16 w2seg w1x1 w2y1 -w10z1 w1x1 w1y1 -w10z2 w2rad
GW 17 w2seg w1x1 w2y1 -w11z1 w1x1 w1y1 -w10z2 w2rad
GW 18 w2seg w1x1 -w1y1 -w10z2 w1x1 -w2y1 -w10z1 w2rad
GW 19 w2seg w1x1 -w1y1 -w10z2 w1x1 -w2y1 -w11z1 w2rad
SY w18z2=16.54007
GW 20 w1seg w1x1 w1y1 w10z2 w1x1 w1y1 w18z2 w2rad
GW 21 w1seg w1x1 -w1y1 w10z2 w1x1 -w1y1 w18z2 w2rad
SY w20z1=8.057982
GW 22 w1seg w1x1 w1y1 w20z1 w1x1 w1y1 w2z2 w2rad
GW 23 w1seg w1x1 -w1y1 w20z1 w1x1 -w1y1 w2z2 w2rad
SY w22seg=3, w22z2=12.29903
GW 24 w22seg w1x1 -w1y1 w20z1 w1y1 w1x1 w22z2 w2rad
GW 25 w22seg w1x1 w1y1 w18z2 w1y1 w1x1 w22z2 w2rad
GW 26 w22seg w1x1 w1y1 w20z1 -w1y1 w1x1 w22z2 w2rad
GW 27 w22seg w1x1 -w1y1 w18z2 -w1y1 w1x1 w22z2 w2rad
GW 28 w1seg w1x1 w1y1 -w10z2 w1x1 w1y1 -w18z2 w2rad
GW 29 w1seg w1x1 -w1y1 -w10z2 w1x1 -w1y1 -w18z2 w2rad
GW 30 w1seg w1x1 w1y1 -w20z1 w1x1 w1y1 -w2z2 w2rad
GW 31 w1seg w1x1 -w1y1 -w20z1 w1x1 -w1y1 -w2z2 w2rad
GW 32 w22seg w1x1 -w1y1 -w20z1 -w1y1 w1x1 -w22z2 w2rad
GW 33 w22seg w1x1 w1y1 -w18z2 -w1y1 w1x1 -w22z2 w2rad
GW 34 w22seg w1x1 w1y1 -w20z1 w1y1 w1x1 -w22z2 w2rad
GW 35 w22seg w1x1 -w1y1 -w18z2 w1y1 w1x1 -w22z2 w2rad
GW 36 w22seg w1x1 w1y1 w2z2 w1x1 w1y1 w1x1 w2rad
GW 37 w22seg w1x1 -w1y1 w2z2 w1x1 -w1y1 w1x1 w2rad
GW 38 w22seg w1x1 w1y1 -w2z2 w1x1 w1y1 w1x1 w2rad
GW 39 w22seg w1x1 -w1y1 -w2z2 w1x1 -w1y1 w1x1 w2rad
SY w38seg=13, w38y1=11.34281, w38z1=24.34884, w38y2=11.32889, w38rad=0.25
GW 40 w38seg w1x1 -w38y1 w38z1 w1x1 w38y2 w38z1 w38rad
SY w39y1=11.29235, w39z1=24.38478, w39y2=11.29234
GW 41 w38seg w1x1 -w39y1 -w39z1 w1x1 w39y2 -w39z1 w38rad
SY w40seg=29, w40y1=11.47796, w40z1=24.35571
GW 42 w40seg w1x1 -w40y1 w40z1 w1x1 -w40y1 -w40z1 w38rad
GW 43 w40seg w1x1 w40y1 w40z1 w1x1 w40y1 -w40z1 w38rad
GS 0 0 0.0254 ' All in in.
GE 0
EK
SY G1=30000000
LD 5 0 0 0 G1
EX 0 1 1 0 1 0
GN -1
SY Freq=174
FR 0 1 0 0 Freq
RP 0 1 73 1510 90 0 1 5 0 0
If it is true, it might be worth losing 1 db in uhf gain.
 

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Hi Lassar
You will need to shorten wire 38 and 39 enough, that their volumes do not intersect/overlap the upright wires. The endpoints don't meet or overlap, but the volume is overlapping. It doesn't make a huge difference in the results, but it does have some effect. Once you resolve this overlap, you should get more reliable results. It looks like you will still see an increase in the HiVHF gain and a small drop in the UHF gain. It also causes higher SWR and more mismatch in impedance, mostly at the lower reaches of the Hi-VHF band. This may or may not be a problem, at your location. It might be a better choice, if you don't need to get those lower Hi-VHF channels, and need the extra Hi-VHF gain. The design is better, across the entire Hi-VHF and UHF bands, if you connect the loop.

Lawrence
 
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