Total DTV for Less than $20

The recent change to the way broadcast television is transmitted has got a lot of people freaking out. This Instructable is a start to finish guide to getting your current television DTV compatible and fully functional. If you already have a DTV compatible television then the steps regarding the Converter box can be ignored.

Overview
1. Get Converter Box Coupon
2. Quench your thirst
3. Amazon a Box
4. Collect a few materials
5. Voila!!!

Step 1: Get a Converter Box

1. go to https://www.dtv2009.gov/ before the end of July 2009 and apply for a coupon.

2. When you receive it purchase a converter box

- I bought a Tivax STB-T8 Digital to Analog TV Converter Box at http://www.amazon.com
- After the coupon and saver shipping $9.99

Comments

[mertyuy]

instead of the spearker wire and antenna connector, could i use something like this? how should i do it? thanks

[j_dog]

well, by the looks of it you are using speaker wire already. but if that is all one wire then no. (it has to be separate wires to each can) and your Coax cable will not work with the UHF or VHF signal that will be coming through the cans. you will need a two screw lead to coax converter. (im not sure on the exact name of the device so somebody please help if i am off on it) theyre able to be easily acquired at Radio shack or online. and again on the wire, it might be a bit heavy. you may as well save it for something that needs that much copper, like a subwoofer in a car or something. the speaker wire needs to only be like 20 gauge. otherwise youre just wasting conductive material.

[doberon]

don´t work, thanks whether, but this idea no catch any signal in this region. Grettings from Mexico City

[Harry3Lime]

Not cutting the cans actually increases the bandwidth.
An early on the fly HAM antenna was vertical Ham antenna called the CANtenna. It was made of metal coffee cans or tin soup cans soldered end to end in a stack approximating the wavelength desired.
Prized for its increased bandwidth, it usually had short lifespans outdoors due to weather damage

[sarkhan]

Just curious here . Would a piece of 3 1/2 " schedule 40 pvc pipe work?  Or would that interfere with the signal?

[vanpaun]

It bothers me to a degree that a soda can picks up these frequencies so well. I wonder how it might affect our food?

[mr.incredible]

Food??? I hope you're joking, right? Break out the foil hats... No differently than any other RF signal that has ever been transmitted. We're not talking microwaves here. Even that has been broadcast for decades and occurs naturally.

[vanpaun]

No no no, its not the radio waves that bother me, its the fact that a soda can picks it up so well.

[Hands Without Shadows]

I guess just to be safe you shouldn't drink from any 2/3 aluminum cans.

[MaXoR]

LMAO ROTFLMFAO!!!!

Priceless! love it man!

[thebriguy]

Anyone read; http://www.popsci.com/science/article/2010-02/disconnected?page=3

The Man Who Was Allergic to Radio Waves

I thougt, 'BS' when I first saw the article but after reading it it raises a few questions...

[jtobako]

"No way to prove"?  Just put your cell on Silent and get a call without answering it-if he passes out, that's proof.  If he doesn't, that's proof as well.

[static]

I can't deny that the author's project worked well for them at their location, BUT...  My comments are for others to consider. For a somewhat tuned antenna it's the length of the elements, in this case the AL cans, that's important, not how far apart the ends are, in this design a portion of the speaker wire is functioning as part of the dipole. Cutting a section out of the can as shown here may quite impossibly reduce the functional bandwith of the antenna  As the author mentioned this is a dipole antenna en.wikipedia.org/wiki/Dipole_antenna using the common 75 ohm TV coax is a much better choice than speaker wire. Place the elements close together so the coax lead to the are as short as possible, seal the open end at the antenna to avoid moisture from entering the coax. Here is a tool to help calculate element length bfn.org/~bn589/antenna.html  use this en.wikipedia.org/wiki/North_American_broadcast_television_frequencies to know what frequency to enter into the calculator for your TV channels of interest. While the data gleaned from www.fcc.gov/mb/engineering/maps/  is based on a model that uses a receiving antenna at 30' doesn't mean you shouldn't try an antenna at other heights or location on the property In the end you may be one of those that broadcast DTV isn't going to work for you where you are at. 

[StupendousMan!]

Static, You make great points. and I like the Links. I did address in step 2 the reason why the 2 CANS happen to work as a "Tuned" antenna (See end of this post).

I do, however, have a question concerning this statement:

"Cutting a section out of the can as shown here may quite impossibly reduce the functional bandwith of the antenna"

What are you saying?:
1. Cutting the Cans may completely yet won't reduce the functional bandwidth
2. Cutting the Cans may Slightly reduce the functional bandwidth
3. Cutting the Cans Won't affect the functional Bandwidth at all

I am reading the statement as "Cutting a section out of the can as shown here may quite possibly reduce the functional bandwidth"

Step 2 Quote:
"UHF (Ultra High Frequency) is the frequencies that the FCC has reserved for the new Digital Television Formats to be transmitted on.

These frequencies range from 300Mhz to 3,000 MHz (3Ghz). This means the wave ranges from 10cm to 1 meter in length, making two of these aluminum cans end to end along with some 18 gauge speaker wire a perfect way to intercept these waves"

[static]

 I'm saying  #2 Cutting the can in the MANNER shown MAY reduce the functional bandwidth  Element diameter( which is reduced for a portion of the cans in this design) is a design consideration for the bandwidth of a transmitting antenna.Even though the reciprocity between a transmitting and a receiving antenna isn't %100, I have to feel why comprise something that *might* be a positive.Here the effective length of the can hasn't been change at all, the length of an antenna element, here the can determines the design frequency of an antenna. In this design there is no demarcation point separating the portion of the speaker wire functioning as part of the antenna and the portion of the speaker wire acting functioning as the lead in. No doubt the speaker wire is also acting as an antenna, and that may be beneficial in some installations or detrimental in others. I wouldn't have said anything at all if one post mentioned duplicating the project didn't work for them.


 
I haven't messed with a simple antenna yet because all indications and experience are pointing me to a medium or large antenna with a preamp at the antenna. For those where a simple antenna is worth the try I'd suggest a dipole cut for 470 MHz, or a dipole cut for 175 MHz if high band VHF is still being used in your area, using standard TV coax between the antenna and TV, that way you don't have worry about keeping the lead in away from metal

[StupendousMan!]

The results are in!!! I feel that it's a fairly good substitute antenna, see the last step for my results. The PVC suggestion for Outdoor use may be your best bet, then placing it at the recommended height (30 feet above the ground) may yield better results than I had.

[molittr]

How many miles away are you?

[MaXoR]

I have a question of my own here. If I were to leave the cans simply alone.... would that help or hinder this antenna's ability to receive various frequencies?

I'm going to try this in a "Bare Bones" set up by simply wiring up two aluminum pop cans, and seeing if they  help me any?!

[MaXoR]

Do the tubes specifically do anything? The only thing I could think of was alignment?

[StupendousMan!]

LOL No, the tube doesn't do anything.  The tube is cardboard which, last time I checked with science, is non-conductive.  The tube is simply to help with alignment as you put it and aesthetics.

[flataffect]

StupendousMan, you say that you get great reception in your basement with this; I'm curious about your local. I live in a rural area and am stuggling to get the number of channels I feel I should get with my antenna and converter box. How close are you to a transmitter?

[StupendousMan!]

See latest post, and the last step. I've updated the Instructable with the results I had mentioned.

[flataffect]

I built one a few weeks ago. Unfortunately it didn't work. This could be due to my own inexperience with the project.

[StupendousMan!]

Here are some tips: 1. Using a multi-meter check for connectivity between the Can and the end of the respective conductor (the end not connected to the Can). Keep in mind that the aluminum can is coated so you'll have to touch it the Cut edge. If the wire has no connectivity to the Can then it certainly will not work. 2. keep the cans from touching on the inside. I'm pretty sure you could get some reception, however, the purpose of the two cans is to create a Dipole antenna, which can't happen if they are touching. So for maximum reception they probably shouldn't be touching.

[StupendousMan!]

I will be testing this in a more rural area this weekend. I'll Let you know the results between two store bought antenna's and my Cheapo Cantenna :-) Additionally I have to look up how far I am from broadcast centers. Just know that UHF has a much shorter range and requires more power to transmit the same distances the older lower VHF frequencies required. Also it's much more line of sight than VHF.

[LetsExplodeSomething]

so how does it work in rural areas? I'm looking to make my grandparents an antenna because they refuse to get cable or a tv not from the early seventies.

[StupendousMan!]

I appologize, but I left the antenna at my cottage and didn't have a DTV box available that weekend. I won't be able to get Test details up for another week or two.

[trike road poet]

How far apart are the cans in the tube? Is this important, or can they touch? I am assuming the two cut away portions are pointing the same way in the tube (out the same side)

[StupendousMan!]

they should Not touch if you can help it. The bundle of wire in the middle should keep the cans from touching. The distance is not all that important, I tried to keep them as close as I felt comfortable yet far enough apart as to hopefully capture the longer waves of the frequency band.

[ironsmiter]

I vote for a pvc pipe and silicon caulk upgrade, for a snazzy outdoor version! :-) Also, consider an upgrade to shielded coax cable. the increase in reception will be noticeable. although, given the wavelength sizes... maybe the3 shielding on your design would be a detriment. Unfortunately, a few select channels, post-digital, continue to occupy high end vhf range. I wonder... how well do other sized cans, and other spacings of said cans, effect reception strength?

[StupendousMan!]

that would be a nice upgrade. I have a few other design ideas for adjusting the rotation of the Can's within the tube, however i have not had a chance to implement them. but I figure you're looking at $5 or $10 more bucks of hardware to make them adjustable.

[ironsmiter]

5 cent adjustable.... a couple wraps of electrical/duck tape, on the uncut bottom of the can. That should get a "snug" fit, that'll hold, but still allow for adjustments