Canadian TV, Computing and Home Theatre Forums banner

1 - 20 of 723 Posts

·
Registered
Joined
·
2,410 Posts
Awsome. It was just a shot in the dark. This thing works!:eek:



This one out performs anything that I've ever tried.

I get all my regular OTA digital and analog channels. No rotor required.

analog: 5,6,9,11,13,19,25,28,31,41,47 [11 channels that's all I ever could get Cdn]

digital: 2.x,4.1,5.1,7.1,9.1,11.1,12.x,15.1,17.1,23.1,24.1,26.x,29.1,36.1,44.1,49.1,51.x,54.x,66.x [30 digital channels]

The front side is facing Toronto [30deg] 52miles, the back face Erie [210deg] 57 miles, Buffalo [86deg] 40 miles to east the side, Hamilton [340deg] 22miles on the other side.

It must be mounted at the tip of the mast and it can't seem to be used with any reflectors or any deflectors. It can not be stacked or ganged. Don't know why? But it outperforms anything I've ever tried.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=9c6be0724b5f66

I'm getting all the way through the tvfool list down to -10NM:D

I'm hoping someone else can build one of these to see if it works in other reception areas.

___________________________

This antenna either has an extremely wide beam width, or it has multiple lobes to be able to cover all these broadcast sources with one single aim.

___________________________

What's in a name? "Stealth Hawk Antenna":

Stealth: At 35ft up on the tip of the mast it is barely even noticable.
Hawk: It looks like a faint siloette of a hawk sitting up on top of the mast.
Antenna: It's a fully functional, stable UHF/VHF Bi-directional antenna.

There are so many builds and trials posted in this thread. Development and improvements are ongoing thanks to all of the contributors of these forums. I have selected some favorites that I would recommend: http://www.digitalhome.ca/forum/showpost.php?p=1149902&postcount=304
 

·
Registered
Joined
·
551 Posts
ota canunck: Your hor. patterns are like flower petals all over the place. Not much gain about 3.8 max.
CM Experimental Antenna Design
CE #933
GW 1 3 0 -1 0 0 1 0 0.005
GW 2 13 0 -1 0 0 -10.4 3.5 0.04
GW 3 13 0 -10.4 3.5 0 -1 7 0.04
GW 4 13 0 1 0 0 10.4 3.5 0.04
GW 5 13 0 10.4 3.5 0 1 7 0.04
GW 6 13 0 -1 0 0 -10.4 -3.5 0.04
GW 7 13 0 -10.4 -3.5 0 -20.4 -3.5 0.04
GW 8 13 0 1 0 0 10.4 -3.5 0.04
GW 9 13 0 10.4 -3.5 0 20.4 -3.5 0.04
GS 0 0 0.0254
GE 0
EK
LD 5 0 0 0 1.008e7 0
EX 0 1 2 0 1 0
GN -1
FR 0 1 0 0 584 0
XQ
EN
 

·
Registered
Joined
·
7,360 Posts
Your hor. patterns are like flower petals all over the place.
On the high channels. On the low channels, its an interesting flat front dogbone type pattern.

Its like the bottom section of a GH with long stubs. The gain curve is centered nicely in the uhf band, so if you designed it in the dark, thats pretty good.

Reflectors should increase gain of course, and just maybe directors will work in this case. The trick is finding the correct spacing and size and shape of the first director.

At 3.8 I shouldn't be getting more than 20-30miles though
Simple antennas are surprising sometimes. The Radio Shack Classic Bowtie (single bay clip on) has a gain of about 2.5 to 4.5 dbi, and if I position it just right, it gets some stations from 61 miles away consistantly. Thats another reason why mileage claims on commercial antennas are nonsense.
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #5
It's a strange little beast for sure! but it's exactly what I was hoping to achieve to avoid the need for a rotor or multiple antennas ganged in 4 different directions.

My goal is to design a single simple antenna that will give me omni-directional characteristics that will reach the target markets for my area. These experimental antennas may not be suitable in all cases. I hope someone can build one of these Hawks and see is it works in other areas.

Go to my original post and check my tvfool and you'll see what I'm trying to acheive. My target markets are severely scattered.

As far as reflectors go,... :eek: this little antenna does not like to be near anything at all.

Simple antennas are surprising sometimes. The Radio Shack Classic Bowtie (single bay clip on) has a gain of about 2.5 to 4.5 dbi, and if I position it just right, it gets some stations from 61 miles away consistantly. Thats another reason why mileage claims on commercial antennas are nonsense.
So, does that mean that a low raw gain on a simple antenna may be cleaner running than a complex antenna design?
 

·
Registered
Joined
·
7,360 Posts
I think it shows more of the importance of location, location, location, heh.
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #7
I tried this Hawk design with 7" legs, with 8.5" legs and with 10" legs.

The 7" leg design did not do well with VHF-hi reception.
The 8.5" leg design was pretty good for VHF-hi reception.
The 10" leg design was awsome for VHF-hi reception.

All of the leg size variants worked well for all UHF 14-51.[analog&digital]

So, the 10" Hawk design works quite well for me for all 7-51 reception and it's somewhat semi-omni-directionalish to suite this scattered market. The VHF capability is important to me because I have VHF12.x Erie, VHF9.1 [future CTV] Toronto and VHF11.1 [future CHCH] Hamilton.

You said it peaks gain at center of the UHF, so that explains why ION[23.1RF] is now coming in more reliable.
 

·
Registered
Joined
·
221 Posts
ota canuck ,

Sweet little design . I`d like to assemble one out of 1/4" rod this wknd and have a few questions. First , are you running a preamp on this to get your Erie area ? What kind of signal strengths are you getting from there ? I`m asking this because Erie is my target market and we seem to have the same distance to Erie .
Did you use a steel mast ? If so is the ant. mounted right up to it or did you space it out a few inches ? I know this will affect direction of it.
I`m interested in giving this a shot . I`ve been trying to come up with something reflectorless for ease of building and longlasting durability . So far the best thing i`ve found was the GH10 elements with 5.6" stubs except it craps out just below digital ch 50. That one is a wanted ch .
Keep up the good work !
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #9
loveota,

300ohn is right. It's all about location, location, location. :( It will be interesting to see what you can get out of this one. Post your tvfool with your results so we can compare. Good luck!

Preamp; wingard ap8780
No stand off is needed away from the mast.
Mount the non-conducting plastic mounting bar at the very tip of the metal masting.
If too much of the metal mast gets into the diamond's airspace it kills the antenna.

My Erie's are all roaming between 50 & 100%. depends on weather and lake fog conditions.

I tried to gang two antennas, but it didn't work. This Hawk seems to be a stand alone beast, it doesn't like company.;)
 

·
Registered
Joined
·
7,360 Posts
The 10" leg design was awsome for VHF-hi reception.
About like rabbit ears, which is better than most uhf antennas for vhf-hi.

Code:
Channel       Raw Gain       SWR
---------     -----------  ------
9               2.35        8.83
11              2.47        7.72
12              2.53        7.43
(actually, a little better than rabbit ears. Rabbit ears fair poorly here : http://www.hdtvprimer.com/ANTENNAS/comparing.html)
 

·
Registered
Joined
·
221 Posts
Stealth Hawk

An amazing little antenna ota canuck !
I built it Sat. but Sunday the signals weren`t normal enough to try it but was very average this morning so i got it put up. Mind you bending 1/4" rod that much left me with large radius bends . I was surprised how well this small ant. recieves . My digital target is Erie. Vhf 12 matched my Gapless GH10 signal wise @ 64% and all my analogs came in with great picture . SunTV 19 ( my only local digital ) matched all other GH`s i`ve tried. Ch. 24 was weak @ 36 % and Fox 66 @ 38% . I need 30% for lock and no pixalating . Ch. 35 & 54 was no signal but i went up and gave the ant. a bit of a twist and then 35 came in but bad pixelating. For some reason my rotor isnt turning , i`ll check that out tomorrow and test some more .
Feedpoint is about 23' and using a CM7777.

http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id=9c6b92873fd7cf



 

·
OTA Forum Moderator
Joined
·
24,867 Posts
Based on ota_canuck's comments and replies from others, I would sum up the best use of this antenna as:
  • Suburban to Fringe distance
  • multi-directional reception
  • primarily UHF, can be built with some VHF-HI capability
  • small mast space
  • easy construction
  • no additional reflectors or other elements work
  • no combining with other TV antennas
  • other good points or corrections?
Nice work, ota_canuck!
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #13
It's a pretty cool looking antenna. Very inconspicuous to use in areas that frown on those big old antennas being mounted outdoors. It would be a great antenna for suburban attic or balcony installations.

The Stealth Hawk does not seem to have a distinct frontside and backside aim, so it's somewhat difficult to initially figure out what direction to aim the front or sides. 300ohm says it has a dogbone reception lobe pattern.

It really amazes me that with so little raw gain, so much can be recieved.

I'm going to try building one using a light gauge flat 3/4" aluminum. It might be a better choice of material just in case some big fat birds decide to come by and roost on it.
 

·
Registered
Joined
·
376 Posts
... Ch. 24 was weak @ 36 % and Fox 66 @ 38% . I need 30% for lock and no pixalating .
You're getting ~ -12NM and -21NM channels with this?? I'm wondering how this can be, but you've definitely piqued my interest enough to try this simple build ... what's to lose? :).
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #15
Simplicity!

I built the first one for a lady who just simply wanted a small window sized antenna for receiving Buffalo channels from her apartment window. As a lark, I threw it up onto my tower to see what it would bring in.

For an apartment window, [being such a simple design] possibly metalic tape layed right onto the glass would do the job. Imagine what results you may get being 20 stories high and having this taped on the window that faces in the right direction.
 

·
Registered
Joined
·
221 Posts
Signals are stronger tonight with the Hawk . Erie 12 has never come in this strong before . 35 is in and steady @ 34% . 54 is still a no show , 24 & 66 are 6% stronger. And i`m kinda in the boonies . I`m impressed.
I`d like to see someone in the GTA area try this one and post back results .
I bet it would be a winner there .
Just a thought , How would that look and perform perched on top of an XG tapped into the Cm7777 for the VHF input ? Then to figure out a distance between them .
 

·
Registered
Joined
·
39 Posts
I'm going to bite and make one out of the 1/4" aluminum stock I have kicking around.. Any ideas as to how much impact the radius bends have on this? From what I'm gathering that this antenna is pretty forgiving all the way around.. Anyone tried a farm of them on separate mounts and different directions?
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #18
Another Stealth Hawk built using flat aluminium.

I made another Stealth Hawk tonight with 8" leg segments using 1/16th" x 3/4" aluminium flat bar.
[I bought a 6ft piece at CTC this afternoon]

Results are just as good as the previous #10 wire models. It's easier to get sharper bends and keep everything evenly aligned using the flat material. I've only tested it at about 20ft over the shop tonight. I will be trying it on my 35ft tower tomorrow to see if it beats the 10" Stealth Hawk that I'm currently using.

Interesting Observations:
I live within 100ft of the local emergency services building in Dunnville and their 2way radio traffic has always been a interference problem. I haven't had any stray interferences from OPP/fire/ambulance 2way radios since I've been using these antennas.

For those who are not aware,.. I used to need three 4221's ganged in various directions to get the same as I get with this one little antenna.

___________________________________________

mogwai;
I don't think the sharp bend radius makes much difference in performance, but the sharper bends will make it easier to measure the gap distances. Gap distances seem to be very important. I've noticed that if the gaps are too big, the higher channels get clipped off.
___________________________________________
 

·
Registered
Joined
·
2,410 Posts
Discussion Starter #19
Check out the analog VHF/UHF reception?

loveota;
Have you tried to scan for analog yet? I'm getting everthing VHF&UHF from Toronto/Hamilton/Paris/FtErie/Kitchener channels lowest VHF 5 CBC and all the way up to something on UHF69
 

·
Registered
Joined
·
600 Posts
something on UHF69
Most likely OMNI2 analog. This is a very interesting design...I may just have to scratch my 2-bay VHF bowtie in the attic and try this one out instead. Could this replace my dual-hoverman's...hmm :confused: time will tell.

Good job ota.
 
1 - 20 of 723 Posts
Top