Antennas Direct VHF Add-On


#4

Oh and cut down that tree just in front of your balcony before it grows any taller. If you do it at night, no one will know…:wink:


#5

All the tv towers are to the south and The tree is to the north. Also to the south is the building and power lines. Satelite was never one of my options, no line of sight. Maybe the trees added to the degrading reception when it got wet. The taller tree to the right is not in the picture.


#6

So the signals are coming through the house to the antenna, not through the courtyard?


#7

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I have no idea but it works. All the buildings are covered with wire mesh and stucco. Maybe it is some reflective thing. All I know is that it is almost impossible to get ABC (VHF) inside the apartment and outside the weather can sometimes cause pixilation.

I just installed a WD Elements desktop hard drive to replace my WD Passport portable hard drive. I did a factory reset to clean things up and when I did the rescan, all the stations that I watch, show solid green. Channels 8 & 27 have always been 3 or 4 dots orange. I saw an increase in strength on all my channels when I added the VHF add-on, including an increase for most of my UHF stations. I hope this improvement is not a fluke and it holds true in wet weather. All the major stations are about 30 miles south of me. My apartment faces NNW.

I have a preamp but the VHF add-on has made the best improvement of anything that I have tried. If it works, it is $15 well spent.


#8

The way the VHF rod is positioned next to the CM antenna, it is probably acting as a reflector for UHF signals onto the CM antenna. A reflector adds about 3 db of signal strength (10-20%). So the kit is acting coincidentally in two capacities - VHF receptor and UHF reflector (directing UHF signals onto the CM antenna). Rods are used as reflectors (like paddle sticks) in many antennas.

Since the house stands between the transmitting towers and the antenna, the antennas in the open may be getting signals bouncing off objects in the area (like the mesh building walls). The CM as omni-directional is positioned to capture signals all around it.

Maybe adding a few more rods will increase the reflection…

Also a VHF antenna can get some UHF signals (not well) and the combiner is adding the VHF antenna’s UHF signal capture to that of the CM’s (if they are in phase). Summing up the signals together increases the signal strength.


#9

Thanks, I just a tweaker. If it works, I ignore it. If it doesn’t work, I try things.


New Antenna Technology
#10

OK, what is the best way to do this? The 72 reading is after adding the foil reflector and the 55 reading was after I removed the foil. I got similar results for channels 4, 8, 11 & 27. I tried a cookie sheet and 2 types of wire cooling racks. Only the foil consistently boosted the readings over a period of time. I had considered ordering a reflector grid sold for use on the clear stream db4 and trying that out at different angles. Appearance is important.

I worry about what will happen to the reception as the trees grow.


#11

Some suggestions (and I’ll try to see what others come to mind later):

Home Depot sells rolls of thin aluminum sheets:

https://www.homedepot.com/p/Amerimax-Home-Products-10-in-x-10-ft-Mill-Finish-Aluminum-Roll-Valley-68310/100054269?keyword=aluminum+sheet+rolls&semanticToken=22040+++>++++st%3A{aluminum+sheet+rolls}%3Ast++cn%3A{0%3A0}++aluminum+sheet+roll+{rest}+

I bought a roll a few years ago, cut it into three pieces and made a solid back reflector. Works magnificently for one of my antennas. This aluminum sheeting is the same material as your kitchen foil but sturdy enough for the outside. And foldable.

You may want to place a sheet of it about 4 to 5 inches directly under the antenna to reflect signals onto it from below (probably 2/3 the size of your circular antenna). Perhaps even bend it on an angle from the railing under the antenna so it forms sort of a trough. See the picture of the antenna reflector(s) bent under the antenna here:

http://www.antennahacks.com/Hacks/MyDB8.htm

The reflectors pictured (the bottom and top reflectors) are called “trough reflectors” You might even make sort of a “V” or “U” with the foil to go under the antenna and over it but at angles that allow a signal through. It would resemble how someone at the beach uses a sun reflector on their face to direct the sun’s rays onto their face by holding it under their chin:

An antenna reflector in effect acts exactly like a sun reflector - to direct and deflect electromagnetic waves onto an object (and the sun’s rays are EM) from different angles. You might have to experiment to see what angles work so as not to block any signals.

BTW type in the words “antenna trough reflector” into Google and when the results come up, click on Images to see pictures of different types of reflector shapes that you may find useful (and aesthetic). Semi-circular shapes are also highly effective.


#12

Another experiment:

Get a tube (rubber, cardboard, plastic - any material). A tube like the one the foil comes wrapped around to allow for unrolling. Wind two or three times around the tube the kitchen foil you are using and make sure it stays wound around the tube. You may even want to stuff inside the tube more foil. Then stick that tube where you have the loose foil. Typically a good reflective aluminum rod or tube for UHF signals would be about 32 inches in length and one inch in diameter.

If it gives you the same results, then it means one can roll up some aluminum sheeting the same way to use as a reflector or even get an aluminum pipe (copper would be just as good). One can even paint a rod or pipe to match the color of your balcony railing and the paint won’t hinder the reflectivity of the rod.


#13

Now for a reflector on one of my antennas I used chicken wire I had sitting around in my basement. Works great. But then your neighbors might consider you a redneck :cowboy_hat_face: hee haw. But this is Texas, right?

BTW the Clearstream reflector is not a bad idea (or even an old satellite dish which people have used as reflectors). Talking about satellite dishes, the best antenna ever built was the Channel Master 4251 which was one massive dish type reflector and a tiny receiver element (really just an old-fashioned two bay bowtie). The humongous reflector would collect all the RF signals and like a magnifying glass beam them back onto the small Radio Shack type bow tie. To this day nothing beats the 4251. But it is huge! It is the Mona Lisa of antennas - a thing of beauty!

My wife and I were driving around one Sunday in the country and I spotted one on an old farm house. I whistled, “What a thing of beauty!” My wife looked at me and couldn’t see what I was looking at. “You lookin at a woman?” she demanded. No, I said, THAT antenna. She thought I was crazy.

Wonder what your balcony railing is made of. Lower the antenna and use the railing as a set of reflectors…


#14

Will try railings later in the week but the spacing, maybe too much for vhf but lowering the antenna sounds good.

Good prototyping idea.

I’ll play around with the foil on cardboard sheets and tubes to see what I can come up with. I was wadding up some foil that I had been playing with when the thought occurred to move the reflector !ower and point it up. I’ll work on that idea. Thanks.


#16

BTW you mentioned that you had an amplifier. Not all amps are equal. Some amps I have bought from Radio Shack and Walmart were not good. They had high noise figures (6 db and more) and did more harm than good. The ones I would recommend would be Winegard, Kitztech, Channel Master and RCA (some RCAs not all). All these have NFs 2 db or lower.

In some cases a good distribution amp if the antenna signal is split many ways.


#17

Channel Master 4 port Preamp model CM-3414


#18

OK that’s a distribution amp. It won’t necessarily bump up the signal significantly - its main job is to ensure that on a split, the signal doesn’t drop because a splitter cuts a signal in half. A preamplifier such as a Winegard LNA 200 or RCA TVPRAMP1Z will boost a signal about twice as much as a distribution amp. In extreme cases I’ve gone with a Kitztech.


#19

I tweaked my antenna today. I tried multiple reflector combinations but nothing made a reliable change in signal strength. I finally turned my VHF addon antenna and got an increase in signal power that has lasted all afternoon. I also removed my distribution preamp for an other increase in the signal strength. Now it is wait for the storms and see what happens. It would be nice if Tablo had a builtin signal meter for monitoring.


#20

Ah yes, a signal meter for the Tablo (which everyone wants).

One way of getting one (but that would be an added expense), is to buy a USB tuner to use with a PC (and many of them come with a PC based real time signal monitor). But that is another $50 to $75.


#21

And of course, still a variable since the run to the PC, is not the run to the Tablo (unfortunately, it can make a difference).


#22

At least an external tuner can validate the antenna’s own performance independently of the Tablo (or any other DVR). Whenever I set up an antenna for a friend, neighbor, relative or acquaintance, I take my USB tuner and laptop with me to ascertain the maximum antenna performance right at the roof or attic. Whatever tuner is used below in the house, at least the antenna’s reception is verified at the source above and before any distribution of signal takes place throughout the home.

Typically I can compare how every tuner in my home behaves with respect to the measurements taken at the antenna and I can grade them. In most cases I can tell how a recording will turn out based on which tuner\DVR was recording a particular show based on these prior measurements. I know which DVR will give me the best pristine recording to archive in my library of shows. For example, I knew exactly what tuners would give me the best copy of the Downton finale to save. The best tuner (using these measurements) gave me an absolutely flawless recording (no pixelation or hiccup for two straight hours) as if the recording came straight off a Bluray.


#23

I can not evaluate the performance of my Tablo tuners but when adjusting the antenna, I can use the signal meter on my tv setup screen because I can see my tv thru the balcony door while I tweak the antenna. An external meter would be handy. When I was using the distribution amp, I could switch inputs on the tv to use the built in meter, now l have move the coax from the Tablo to the TV.


#24

8[quote=“MarkKindle, post:8, topic:14542”]
Since the house stands between the transmitting towers and the antenna, the antennas in the open may be getting signals bouncing off objects in the area (like the mesh building walls). The CM as omni-directional is positioned to capture signals all around it.
[/quote]

Thanks for pointing me in this direction. Playing with refectors and antenna direction, I found a sweet spot on the building across from me.

I found a broken coax connection on my VHF antenna. After I fixed that, mild pixillation was occuring while my signal strength remained good. Because of the interference, I decided that I needed to move away from the omnidirection Smartenna. So I started looking at small yagi antennas. I looked at the CM Stealthtenna but l liked the looks of the RCA ANT750E. I like the size , the reflectors and the reviews. So far it has increased and helped stabilized my signal strength. Channel signal signal is running from 47 on NBC to 75 on Fox. When the storms get here later this week, I’ll have a better idea about how it will work. I expect some pixcilization in the storms and weather changes but I hope I will not have any recordings dropped for a weak signal. In the mean time the antenna looks good. The Smartenna box look was neat but no class.

I also tried a Channel Master CM-7778 moderate preamp at the antenna mast. It seemed to help a little but it cause pixcilization that went away when I removed the preamp. I ordered the preamp from Walmart. They gave me the best price and knocked off an extra $5 for using their app. They delivered free the next day and I can return it to any Walmart store.

Interesting, my strongest signal strengths are when I point the antenna back at my own building but I also get more pixcilation pointing back at my own apartment.