Canadian TV, Computing and Home Theatre Forums banner

21 - 33 of 33 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #21 (Edited)
Thank you. So I stuck my antenna out a second story window, same antenna, same TV, same direction, etc and it is worse than in the attic. It didn't even get UHF. Of course the attic is higher. I will take everyones advice and build one with the 9 inch whiskers, put it in the attic and call it a day. I hope it gets better UHF as well. Next weekends project. Thanks for the advice.

11360
 

·
Registered
Joined
·
41 Posts
That looks better for VHF-Hi. The first one isn’t bad for a first attempt. I remember building a similar one about 15 years ago. The real fun is in tweaking designs, after you’ve learned what works and what doesn’t. The more you build, the easier they get.
 

·
Registered
Joined
·
112 Posts
I recommend HiVHF+UHF M4 (9.5x9) Bowtie-In-RectLoop.

36 inches high by 24 inches wide.

UHF Gain: 8.1 to 12.2 dBi and SWR under 3.8
Hi-VHF Gain: 4.3 to 4.7 dBi and SWR under 4.0
That should be enough gain to get the vhf & uhf channels.

Should get all local channels.

Works best, if you can get the antenna outside, or in a
windows facing the stations broadcast antenna.

If you are going to put the antenna outside, use pvc pipe to make it.
 

·
Registered
Joined
·
112 Posts
One of the things to be careful on is the coaxial F connector to
the 300 ohm to 75 ohm transformer.

I usually bent the f connector pin to the side slightly, and
connect it to the transformer to get a better connection.

Same goes for the f connector to the tv.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #26
However a guy near me has this for sale, a Clear Stream 4 Max for $75. Not sure how that would compare.Opinions?


11383
 

·
Registered
Joined
·
130 Posts
Clear Stream 4 Max separates Hi-VHF and UHF reception, and combines them, before the antenna output. Hi-VHF is provided by the long horizontal rod, on the back of the design. UHF is provided by the two figure 8 loops. Reception pattern, from combining two equal antennas side by side, is usually very directional. Since the design does not have a reflector, it will pick up signals from directly in front and directly behind the antenna. It won't have much reception from either side. This may work OK at your location, if aimed north/south. I'm not sure if you are wanting to pick up any of the channels coming in from the east or west. It may be too directional, to pick up channels from the sides. The 4bay antennas, that have been recommended, should have a wider reception pattern, and give better results for channels, coming in from the sides.
 

·
Registered
Joined
·
130 Posts
I did a quick and dirty model, of the UHF portion, of the Clear Stream 4 Max. I used Holl_ands model for the single figure 8 and created a double figure 8. As I suspected, it has good gain to the front and rear. It has very little gain directly to the sides(see pattern below).

11384


If you compare it to the M4 bowtie in loop, you see similar patterns. They both have very good gain directly in front and behind the antenna. Reception is OK out to 45 degrees, but drop to almost zero directly to the sides. The M4 does have a bit better UHF reception, off axis, but not by very much. Signals get bounced off of things, and bend around things, so you may still pick up UHF signals from the sides. The Hi-VHF reception is a little better for the M4, and the reception pattern looks to have better off axis reception, than the 4 Max dual figure 8. I think either one will work better, than what you have now, but I think the M4 with loop is probably the better design, for your location. Better design doesn't always mean better antenna. How much do you want to spend, and how much will you enjoy building a new antenna. Keep in mind that the M4 in loop will require a more careful build, than the simple 4 bay that you built earlier. Distances from bowties, to the loop must be kept very close to the modeled dimensions.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #31
Do I really need to use 10 gauge wire? I already have a large spool of 14 gauge. Does it make any difference?
 

·
Registered
Joined
·
130 Posts
Do I really need to use 10 gauge wire? I already have a large spool of 14 gauge.
It looks like you will give up a couple of tenths of a decibel of gain, with the smaller wire size. Not really enough to make a difference. #14 wire won't be as stiff, so it may be more likely to get bent/damaged, over time. It shouldn't be a big issue, if you mount it in your attic. Frame was designed to be a metal picture frame. i modeled it using 1/2 copper tubing, and it works OK, as well. 1/2" copper tubing, with 90 degree elbows for corners, works well, if you can solder the joints. Since this is an electrical application, it's best to use rosin flux when you solder the joints. I've used standard plumbing flux, but long term, the joints will be better if you can get rosin flux.
 
21 - 33 of 33 Posts
Top