GHxN3 choice?

[lezarp]

Hello

I use an haupauge pvr 1800 ( HTPC) a little bit less sensible as a standard digital tv tuner I think.
my tvfool report:
http://www.tvfool.com/?option=com_wr...3e47258d8501e3

I have build this ugly scrappy antenna http://uhfhdtvantenna.blogspot.com/
. I use wood I know it is not really good …
And without reflector ( to bidirectional capability for US channel) with a GE amp http://www.canadiantire.ca/AST/brows...p?locale=fr_CA
No comment 5.3Db noise …
But I work good enough.
With this "equipments"(haaa! haaa! haaa! equipments…) I have a good enough reception of all 14 upper channel on the top list from src 2 to NBC 14 (5.1). The signal is variable (on my software signal tester) from half to full with some numerical error correctable ( no visual artifact or error)
for PBS 57.1 and 33.1 it depend of the orientation Some time I have 57.1 some time 33.1. some time both (but weak).
But I am not be able the have Fox and ABC and both PBS
So I want a long range antenna
And I have some question:
I am interested to build a GH6n3 or GH8n3 as see http://clients.teksavvy.com/~nickm/gh_n3_uV.html.

1) is it a good choice ? ABC use 13 as real channel.

2) I have read "he models are optimized for building using 1/4" T6 aluminum.". At specialized Supermarkets ( I have ask at 2 different place) pipe cost about 15$ for 72'' . the GH6n3 antenna requied about 500'' So it will cost about 100$ !!!!! for an homemade antenna…
But cooper 16gauge wire is really cheap. And I will put the antenna in the attic. If I just replace aluminium by copper wire the peformance will change. But I would to know if the antenna will still really good enough?

3)Or some body could provide me the design of GH6/8 n3 for copper wire 16G. ?
I think, A wired copper design could be usefull for lot of people ( low cost, easy to build, perfect for an indoor/attic usage) If it cost less more people will try to build one VS paying 100-150$ for an channel master antenna or for an other brand.

4) I think I will replace GE amp by a CM7777 but I don’t know if this one will not be to powerful for my local station. Is a powerful amp /pre-amp dangerous for my equipments ?

5) can I couple 2 same GHx together ? is yes how ?

Thank

[300ohm]

1) is it a good choice ? ABC use 13 as real channel.

A GH0n3 is a better choice, then you could catch the stations front and back without a rotor. It should be up high outdoors. Also much easier to build.

At specialized Supermarkets ( I have ask at 2 different place) pipe cost about 15$ for 72'' .

Thats way too much for 6 ft of rod. Even Lowes and Home Depot and Ace Hardware are cheaper than that. Most Canadians are paying about 35 cents a foot for 1/4" aluminum rod at Metal Supermarkets.

4) I think I will replace GE amp by a CM7777 but I don’t know if this one will not be to powerful for my local station. Is a powerful amp /pre-amp dangerous for my equipments ?

Yeah, with a CM7777 youll overload on the locals. A good choice would be the Winegard HD-269.

[lezarp]

hello

Thank for your prompt reponce!

rod price was checked today at rona and home depot
So i will try found a Metal Supermarkets.

A GH0n3 ! i am surprized because gain look not so high a 14 and 13 ( ABC) at 70 milles. But i absolutly don t know what i need . and how gain is important.

In my mind a GH2n3 was a minimum requirement in my case.

And an important point. it must be in the attic. Rules for joint ownership don't allow me to add an anntena outside.

So a GH0n3 still a good choice ?

thanks

Thanks

[300ohm]

A GH0n3 ! i am surprized because gain look not so high a 14 and 13 ( ABC) at 70 milles.

14 should be fine with any GH, but 13 could be iffy with any in the attic. A GH4 may be the compromise way to go with a little bit more gain for 13, while leaving enough backside gain for the channels at around 300 degrees. You lose a lot of gain in the attic, so you really wont know until you build it.

[nikiml]

Originally Posted by lezarp

2) I have read "he models are optimized for building using 1/4" T6 aluminum.". At specialized Supermarkets ( I have ask at 2 different place) pipe cost about 15$ for 72''.

Pipe is usually more expensive than solid rods.
Unfortunately Metal supermarkets has no stores in Quebec, but I am sure there are other metal suppliers there. Just look up the yellow pages.

[300ohm]

Yeah. Good point, I overlooked he said pipe.

Home Depot carries 1/4" aluminum pipe ? In what dept ?

[nikiml]

may be something like that will work well, it has good gain from the back and wide beam at the front.

CM
CM XGH4n3 - optimized by nikiml
CE

SY radius=0.003175
SY narod_surf_spacing=0.006
SY narod_spacing =  narod_surf_spacing+2*radius

SY feed=0.03769505' 0.02, 0.07

SY b=0.2031652' 0.075, 0.25
SY a1=0.138868' 0.07, 0.22
SY _G3=0.06152366' 0.006, 0.1
SY a2=a1+feed-_G3'this is to avoid self intersection since _G3 is to be > radius+2.5mm
SY a3=0.1961832' 0.07, 0.22
SY _G5=0.01339152' 0.006, 0.1
SY a4=a3+_G3-_G5'this is to avoid self intersection since _G3 is to be > radius+2.5mm
SY a5=0.1964093' 0.07, 0.22
SY _G7=0.02837265' 0.006, 0.1
SY a6=a5+_G5-_G7'this is to avoid self intersection since _G3 is to be > radius+2.5mm
SY a7=0.1865463' 0.07, 0.22

SY x=-0.07459791' -0.06, -0.1
SY g1=0.01041195' 0.002, 0.1
SY l1=0.2257665' 0.1, 0.65
SY g2=0.04354869' 0.002, 0.1
SY l2=0.5828862' 0.1, 0.65

SY n_h=0.09879433' 0.05, 0.14
SY n_f_dx=0
SY n_top_dy=0.008404796' -0.04, 0.04
SY n_b_taper=0.02230232' 0, 0.06
SY n_top=_G7+a7+n_top_dy- n_b_taper/2'hat head size
SY n_f=x + n_f_dx'so the hat does not tilt behind the reflectors


SY narod_top = a1+a2+a3+a4+a5+a6+a7+narod_spacing+n_h'want to put 2 reflectors between z=very_small and z=narod_top - very_small
SY dz2=0.1486577' 0.02, 0.2

SY z2 = -dz2+narod_top
SY dz = z2/3

SY dz1=0.4399408' 0.2, 2
SY z1 = (1+(dz1-1))*dz

SY ay1=feed+a1
SY ay2=feed+a1-a2
SY ay3=feed+a1-a2+a3
SY ay4=feed+a1-a2+a3-a4
SY ay5=feed+a1-a2+a3-a4+a5
SY ay6=feed+a1-a2+a3-a4+a5-a6
SY ay7=feed+a1-a2+a3-a4+a5-a6+a7
SY ay8=feed+a1-a2+a3-a4+a5-a6+a7+b
SY az2=a1+a2
SY az3=a1+a2+a3
SY az4=a1+a2+a3+a4
SY az5=a1+a2+a3+a4+a5
SY az6=a1+a2+a3+a4+a5+a6
SY az7=a1+a2+a3+a4+a5+a6+a7
SY n_b_z=az7+narod_spacing
SY n_b_y1=n_top+n_b_taper
SY n_b_y2=n_b_y1+b

SY n_z_coef=0.6178802' 0.5, 1.4
SY n_zsz=0.5005028' 0.3, 0.55
SY n_0sz=0.42592' 0.3, 0.6
SY n_x_diff=0.2071873' 0.15, 0.4
SY n_x = x-n_x_diff
SY n_z = narod_top*n_z_coef


GW 1 10 0 feed 0 0 ay1 a1 radius
GW 2 9 0 ay1 a1 0 ay2 az2 radius
GW 3 15 0 ay2 az2 0 ay3 az3 radius
GW 4 18 0 ay3 az3 0 ay4 az4 radius
GW 5 15 0 ay4 az4 0 ay5 az5 radius
GW 6 14 0 ay5 az5 0 ay6 az6 radius
GW 7 14 0 ay6 az6 0 ay7 az7 radius
GW 8 11 0 ay7 az7 0 ay8 az7 radius
GW 9 12 x g1 z1 x l1+g1 z1 radius
GW 10 31 x g2 z2 x l2+g2 z2 radius
GW 11 7 n_f n_top n_b_z+n_h 0 n_b_y1 n_b_z radius
GW 12 11 0 n_b_y1 n_b_z 0 n_b_y2 n_b_z radius
GX	20	010
GW 13 23 n_f -n_top n_b_z+n_h n_f n_top n_b_z+n_h radius
GW 15 53 n_x -n_zsz n_z n_x n_zsz n_z radius
GX	40	001
GW 16 45 n_x -n_0sz 0 n_x n_0sz 0 radius
GW 100 7 0 -feed 0 0 feed 0 radius*.8675
GE	0
LD	5	0	0	0	24900000
GN	-1
EK
EX 0 100 4 0 1
FR	0	0	0	0	800	0
EN

[lezarp]

Hello,

Do you use anodized aluminium rod or not ?
Because inodisation is used to electrical insulation.
Stupide question but....

Thanks

Don`t worry , when my antenna will be done, i will post results

[majortom]

Yeah, with a CM7777 youll overload on the locals. A good choice would be the Winegard HD-269.

If you plan on driving more than 2 Tuners (i.e. more than a 2 way Split), I'd use the Winegard AP 8700. It only has 17 / 19 dB VHF/UHF gain with a decent 2.8 dB NF. Like the HD 269, it can also handle stronger signals than the CM-7777 can.

[300ohm]

Do you use anodized aluminium rod or not ?
Because inodisation is used to electrical insulation.

Anodized aluminum is fine, and is used in commercial antennas.
The anodized layer is so thin, it compares favorably to the aluminum oxide that would form anyway.

The GH elements would be one piece, but you would want to clean the balun connection point areas. On the colinear reflectors, it doesnt matter.

[lezarp]

Hi guys.

A long time ago in a galaxy far, far away ( mmm yes it sound a little bit geek)

Don`t worry , when my antenna will be done, i will post results

No this is not a zombie thread

So this first re-post is for a pre-result and for ask some opinion.

I have finaly found time to bluid my antenna ( tv is not a top priority in my life , baby, wife, job, etc....)). The antenna build was really a EPIC story. I will give more detail in the next post.

I have build a GH4n3 from this blue print (http://clients.teksavvy.com/~nickm/g..._9V6_13u5.html)

I have place the antenna in the attic.

I finally receive all desired channel on my small (kitchen TV 22').
http://www.tvfool.com/?option=com_wr...99003a6df25adb
the list of my channels

near transmitter
2.1
3.1
5.1
6.1
10.1
12.1
15.1
17.1
29.1
35.1
long distance transmitter
33.1
44.1
57.1
It run since 1 week now and no one have drop (weakest signal are always stable and image and sound have good quality , not discontinued)
----

But to have this result i must point directly on the 35.1 transmitter (35.1 and 17.1 have not strong signal. fox and both pbs give me a better reception signal .!!!! unbelievable !!!!

Strange think, i receive fox (44) only when i put ( accidentally my old ugly antenna http://uhfhdtvantenna.blogspot.com/ ) at 1 meter in front of my GH4n3 with a 45 degree angle. this append just because i have no space in my attic. This have no impact on other Chanel.


But some problem are always present with my tv in the living room ( A old TV with a Home Theater PC (HTPC) the pc card is a 1800 hauppage ).

In the living room i don't have
3.1 and 5.1 : tvfool say have are adjacent channel and cochannel potential problem.

17.1 and 35.1 : are just not detected. after some reading on forum , some people tell my it is beaucse , transmitter are not enough high and in my direction lot of building reduce signal strong ( i am not the only one whit this problem).
12.1 : is just not detected . I don t know why.

Actually i have the antenna plugged on my old GE pre-amp ( 24 db). to a spliter ( non brand) from 1 input to 6 output. and from the spliter directly to all wallplug. I have try a 1 in 2 out splitter (3.5 db) but i can not see difference.

In my attic i don t have enough space for a bigger antenna. But i can add a second GH4n.

So my idea is buy :
2 Winegard AP 8700 ( one for the present antenna to replace the GE preAMP and one for the futur antenna (GH4n , the same one )
1 winegard 7870 coupler

So i hope increase my signal reception strong on my htpc with 2 antenna on the same transmitter.

And just in case. some one know a PC TV card good for weak and medium signal ?

Thank for reading.

When i will receive pre amp, probably in 3 week ( depending of your comments), i will take and post some photo in the attic of the antenna( and i will explain how to bend aluminum whit a char coal BBQ only for professional ).

[300ohm]

But to have this result i must point directly on the 35.1 transmitter (35.1 and 17.1 have not strong signal. fox and both pbs give me a better reception signal .!!!! unbelievable !!!!

With a NM of around 50, 35.1 and 17.1 are overloading. The Winegard AP 8700, while better than your GE preamp, probably isn't going to help matters. Give it a try, but be prepared to return it.

And just in case. some one know a PC TV card good for weak and medium signal ?

The 950Q usb tuner stick is a bit better than your 1800, as it uses a 6th gen tuner chip. So do a lot of the AverMedia cards, but you may not like the software as well as the Hauppauge. Of course, you could use Windows Media Center.