[Herr Klanknratl]

Has anyone built and or modeled any Hoverman using an aluminum boom and mounting the reflectors directly to it?I'd appreciate any comments on this construction method as I have several old tv antennas with 1" square booms and lots of usable elements and aluminum mounting clips.This would make a light weight and easy to construct antenna if it functioned correctly.
I've built a sbgh gapless using an aluminum reflector boom but the reflectors are electrically isolated from the boom. It seems to work ok but I don't have a pvc framed one to reference it to.
I've got 4nec2 but haven't been able to devote any time to learning it hence the questions here.
If I wanted to boost one particular channel's reception in the uhf portion would cutting 4 narods to 1/4 wave & putting them on the driven element help?
I'd like to build a dbgh gapless using this method if its viable. Anybody care to model it & post the drawing/specs for it?
My tvfool-

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=9fbee9cc839333

Thanks! Andy

 

[300ohm]

Without the gaps in the reflector, you lose gain.

I'd appreciate any comments on this construction method as I have several old tv antennas with 1" square booms and lots of usable elements and aluminum mounting clips.This would make a light weight and easy to construct antenna if it functioned correctly.

Mlord and others have built using an aluminum frame, but the gaps were insulated using plastic.
I would find some grey pvc gutter ferrules, theyre perfect for 3/8" tubing, and use those in your build.

Jed does have a gapless design here :
http://www.jedsoft.org/fun/antennas/dtv/gapless.html

If I wanted to boost one particular channel's reception in the uhf portion would cutting 4 narods to 1/4 wave & putting them on the driven element help?

Definately not, and would mess things up badly. NARODs are for VHF.

 

[Herr Klanknratl]

clarification

Hi Mr. 300Ohm & thanks for responding.I guess I didn't express clearly what I have or what I'm trying to do.
I currently have a jed gapless sbgh with 1/4"dia. driven and 1/4"dia. reflector elements.The reflector elements pass through the 1" square aluminum boom and are insulated electrically with nylon shoulder washers.The elements are made with 1/4" diameter tubing,not rod as specificied in jed's design.The antenna is tilted up 10 deg. and feeds the antennacraft 202 preamp through a 1/4 wave balun cut for 500mc.This works better than ones cut for higher or the center freq.
What I'd like to do is build an antenna that is jed style gapless but with an aluminum boom with the reflectors connected directly to the boom.Yes I know that would change the design parameters and probably performance but with no skill with nec I was hoping someone could give feedback on this idea.
The whole idea behind this is an antenna thats lightweight , simple and cheap to build with no "special" parts to buy-junk antennas, some nuts&bolts,and driven element material.
So what do you think?

 

[300ohm]

The elements are made with 1/4" diameter tubing,not rod as specificied in jed's design.

Because of the surface effect, theres no difference in performance between tubing and solid rod, especially for reflectors or directors.

So, you want to see the difference in performance in JEDs gapless model if all the reflectors were connected directly to a 1" boom, with say a 4" overhang on each end ? Ill have to model that a little later.

 

[300ohm]

So, you want to see the difference in performance in JEDs gapless model if all the reflectors were connected directly to a 1" boom, with say a 4" overhang on each end ? Ill have to model that a little later.

That will work fine. There is very little difference in the gain and SWR graphs on the 7mm version that JED has posted here : http://www.jedsoft.org/fun/antennas/dtv/gapless.html

so I wont repost the graphs.

NEC file:

CM hov15-hovzz3-RgaplessN12z2_D7mm_diffev_7mm7mm
CM 1 inch boom, connected to reflectors,  4 inch overhang added by 300 ohm
CM AGT = 1.0(0db) at 600mhz, auto-segmentation = 21, warnings about 1" boom too thick
CE
GW	1	9	0	-1.7299567	0	0	1.72995669	0	0.12
GW	2	21	0	-1.7299567	0	0	-7.6549213	5.92496063	0.13779528
GW	3	21	0	-1.7299567	0	0	-7.6549213	-5.9249606	0.13779528
GW	4	21	0	1.72995669	0	0	7.65492126	5.92496063	0.13779528
GW	5	21	0	1.72995669	0	0	7.65492126	-5.9249606	0.13779528
GW	6	21	0	-7.6549213	5.92496063	0	-1.9935984	11.5862992	0.13779528
GW	7	21	0	-7.6549213	-5.9249606	0	-1.9935984	-11.586299	0.13779528
GW	8	21	0	7.65492126	5.92496063	0	1.99359843	11.5862992	0.13779528
GW	9	21	0	7.65492126	-5.9249606	0	1.99359843	-11.586299	0.13779528
GW	10	19	0	-1.9935984	11.5862992	0	-7.3902362	16.9829528	0.13779528
GW	11	19	0	-1.9935984	-11.586299	0	-7.3902362	-16.982953	0.13779528
GW	12	19	0	1.99359843	11.5862992	0	7.39023622	16.9829528	0.13779528
GW	13	19	0	1.99359843	-11.586299	0	7.39023622	-16.982953	0.13779528
GW	14	11	0	-7.3902362	16.9829528	0	-11.721457	16.9829528	0.13779528
GW	15	11	0	-7.3902362	-16.982953	0	-11.721457	-16.982953	0.13779528
GW	16	11	0	7.39023622	16.9829528	0	11.7214567	16.9829528	0.13779528
GW	17	11	0	7.39023622	-16.982953	0	11.7214567	-16.982953	0.13779528
GW	18	61	-3.202287	-23.9076	-23.17283	-3.202287	0	-23.17283	0.1377953
GW	19	61	-3.202287	0	-23.17283	-3.202287	23.907598	-23.17283	0.1377953
GW	20	37	-3.202287	-14.02713	-17.77736	-3.202287	0	-17.77736	0.1377953
GW	21	37	-3.2022874	0	-17.777362	-3.2022874	14.027126	-17.777362	0.13779528
GW	22	49	-3.202287	-19.38854	-12.92795	-3.202287	0	-12.92795	0.1377953
GW	23	49	-3.202287	0	-12.92795	-3.202287	19.388543	-12.92795	0.1377953
GW	24	49	-3.202287	-19.14921	-8.602992	-3.202287	0	-8.602992	0.1377953
GW	25	49	-3.202287	0	-8.602992	-3.202287	19.149213	-8.602992	0.1377953
GW	26	15	-3.202287	-5.767008	-4.781024	-3.202287	0	-4.781024	0.1377953
GW	27	15	-3.202287	0	-4.781024	-3.202287	5.7670079	-4.781024	0.1377953
GW	28	35	-3.202287	-13.26264	-1.440398	-3.202287	0	-1.440398	0.1377953
GW	29	35	-3.202287	0	-1.440398	-3.202287	13.262638	-1.440398	0.1377953
GW	30	35	-3.202287	-13.26264	1.4403976	-3.202287	0	1.4403976	0.1377953
GW	31	35	-3.202287	0	1.4403976	-3.202287	13.262638	1.4403976	0.1377953
GW	32	15	-3.202287	-5.767008	4.7810236	-3.202287	0	4.7810236	0.1377953
GW	33	15	-3.202287	0	4.7810236	-3.202287	5.7670079	4.7810236	0.1377953
GW	34	49	-3.202287	-19.14921	8.6029921	-3.202287	0	8.6029921	0.1377953
GW	35	49	-3.202287	0	8.6029921	-3.202287	19.149213	8.6029921	0.1377953
GW	36	49	-3.202287	-19.38854	12.927953	-3.202287	0	12.927953	0.1377953
GW	37	49	-3.202287	0	12.927953	-3.202287	19.388543	12.927953	0.1377953
GW	38	37	-3.202287	-14.02713	17.777362	-3.202287	0	17.777362	0.1377953
GW	39	37	-3.2022874	0	17.7773622	-3.2022874	14.027126	17.7773622	0.13779528
GW	40	61	-3.202287	-23.9076	23.172835	-3.202287	0	23.172835	0.1377953
GW	41	61	-3.202287	0	23.172835	-3.202287	23.907598	23.172835	0.1377953
GW	42	9	-3.2022874	0	23.1728346	-3.2022874	0	27	0.5
GW	43	13	-3.2022874	0	23.1728346	-3.2022874	0	17.7773622	0.5
GW	44	11	-3.2022874	0	17.7773622	-3.2022874	0	12.9279528	0.5
GW	45	11	-3.2022874	0	12.9279528	-3.2022874	0	8.60299213	0.5
GW	46	9	-3.2022874	0	8.60299213	-3.2022874	0	4.78102362	0.5
GW	47	9	-3.2022874	0	4.78102362	-3.2022874	0	1.44039764	0.5
GW	48	7	-3.2022874	0	1.44039764	-3.2022874	0	-1.4403976	0.5
GW	49	9	-3.2022874	0	-1.4403976	-3.2022874	0	-4.7810236	0.5
GW	50	9	-3.2022874	0	-4.7810236	-3.2022874	0	-8.6029921	0.5
GW	51	11	-3.2022874	0	-8.6029921	-3.2022874	0	-12.927953	0.5
GW	52	11	-3.2022874	0	-12.927953	-3.2022874	0	-17.777362	0.5
GW	53	13	-3.2022874	0	-17.777362	-3.2022874	0	-23.172835	0.5
GW	54	9	-3.2022874	0	-23.172835	-3.2022874	0	-27	0.5
GS	0	0	0.0254		' All in in.
GE	0
EK
LD	5	0	0	0	2.49e7	0
EX	0	1	5	0	1	0
GN	-1
FR	0	1	0	0	600	0
RP 0 1 36 1001 90 0 5.0 10 10000 0

 

[Herr Klanknratl]

Thanks Mr. 300Ohm

Thank you Mr. 300Ohm for checking my idea on nec.I'm really surprised however that the parameters didn't change.
I really need to learn nec but every time I start on it wifey thinks I'm "playing" and asks me to look up the price of some shoes for her or something and gets huffy when I tell her I'm studying a technical program . Then I get "don't worry about me. I'll get someone else to do it." Gaaah.
Thanks again
Cheers
Andy

 

[300ohm]

I'm really surprised however that the parameters didn't change.

The change was very very small, and actually on the good side. Impossible to notice the change in real life viewing.

Note:
Also leave the end points of the reflectors open. Connecting the end points, with 7mm wire, causes a sharp dip in gain from 500 - 520 mhz. So a mesh in that shape would also be problematic.