DIY fractal antenna not picking up any VHF stations (channels 2-11)

1DJ6Bz

DTVUSA Rookie
#1
Hi everyone,

I just finished making a DIY fractal antenna to pick up OTA digital signals according to a template I found in one of the postings on this instructable:

How to make a fractal antenna for HDTV / DTV plus more on the cheap

It picks up 23 channels on the UHF side, channels 14+. However I'm not picking up channels 2-11.

I'll try to use another matching transformer once I get a chance to pick one up, but the one I'm using picks up all channels if I connect it to my rooftop antenna, but fails on channels 2-11 on my DIY antenna.

Any ideas? Attached is a picture of my DIY fractal antenna. My zip is 95138.

 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#3
I've seen posts where others have added a pair of VHF-hi elements at the points where the balun is attached. Make each element about 14 inches long. They should extend straight out.
 

1DJ6Bz

DTVUSA Rookie
#4
Thanks everyone for your replies. I did some more research and the particular channel I'm interested in, 2-KTVU, does broadcast in UHF. I guess my antenna just isn't good enough.
 
U

Unregistered

Guest
#6
Nothing wrong with the fractal

Hi everyone,

I just finished making a DIY fractal antenna to pick up OTA digital signals according to a template I found in one of the postings on this instructable:

How to make a fractal antenna for HDTV / DTV plus more on the cheap

It picks up 23 channels on the UHF side, channels 14+. However I'm not picking up channels 2-11.

I'll try to use another matching transformer once I get a chance to pick one up, but the one I'm using picks up all channels if I connect it to my rooftop antenna, but fails on channels 2-11 on my DIY antenna.

Any ideas? Attached is a picture of my DIY fractal antenna. My zip is 95138.

The fractal works fine. The size scale you made wasn't designed for VHF, just UHF. Also, putting this on wood is a major no-no, as wood is an RF absorber at these frequencies. Best would be the pink or blue insulation styrofoam

Good Luck!

The 'Source'
 

ghz24

DTVUSA Jr. Member
#7
Nothing wrong with the fractal

There's nothing "wrong" with fractals but there isn't much right with that specific antenna.

There aren't any 3 bay commercial antennas for a reason (2 bays perform better).
The "unregistered guest" is right about the scale being wrong for VHF.
Before you decide to build this antenna you should look at the OPs signal strengths.
If you have signals as strong as his you to can get a signal on almost any random exposed wire.
Fractal is the buzz word in antennas now but that is because of their wide-band but nominal gain performance , small size and easy manufacture as part of the printed circuit board of small handheld devices.
 
G

Guest

Guest
#8
The frequencies for Channels 2 thru 6 were actually reassigned to other services. What we call channel 2 really isn't channel 2. Virtual channel 2-1 is actually on digital channel 44 (ironically Virtual channel 44-1 KBCW, is on digital channel 45).

It's going to be a long haul for you to use a small fractal antenna to pick up KTVU, which is all the way up on Sutro Tower, in San Francisco.

You can check info for your location at TV Fool. When I entered your zip code, most channels show up as "Blue" antennas, which mean a basic antenna (like this teeny fractal) aren't likely to cut it).

TV Fool

Good luck!

Robert

Hi everyone,

...It picks up 23 channels on the UHF side, channels 14+. However I'm not picking up channels 2-11.

I'll try to use another matching transformer once I get a chance to pick one up, but the one I'm using picks up all channels if I connect it to my rooftop antenna, but fails on channels 2-11 on my DIY antenna.

Any ideas? Attached is a picture of my DIY fractal antenna. My zip is 95138...
 

n2rj

Moderator
Staff member
#10
The frequencies for Channels 2 thru 6 were actually reassigned to other services. What we call channel 2 really isn't channel 2. Virtual channel 2-1 is actually on digital channel 44 (ironically Virtual channel 44-1 KBCW, is on digital channel 45).
Not really true.

2-6 are still allocated to TV broadcast. However they are pretty poor for ATSC digital transmissions.

But you're right that virtual channel 2 may not be real channel 2.
 
#11
Make Grabbit Ears. They recieve all channels and are three bay-one that works great!
Holy smokers! All the hundreds of hours I've put in searching on antennas, and I've never seen the Grabbit Ears. I saw a couple comparisons to the CM-4228. Does this really work as well in *all* or virtually all situations?? Or just in a few situations?

Rick
 
#13
Grabbit Ears are the real deal. I do believe that Grabbit Ears are the best indoor antenna. They recieve all channels 2-12 and on up. They have outperformed other indoor antennae and sometimes some outdoor antennae. They have worked in the most difficult places. Additionally, the signal recieved is "clean". I say this because they suffer no ill affects when amplified. Amplification is suggested if you are 45+ miles out, or just need to pick up a couple of weak ones.

In ONE instance, a CM-4228 on an amplifier was what it took to recieve signal in a high noise environment. (Cell tower approx. 150 ft. away) When I later substituted Grabbit Ears for the CM-4228, the signal was nearly identical.

In comparing the CM-4228 to Grabbit Ears at my home, this was my experience (I'm about 30+miles from transmitters:
When both are used outside on a mast, the CM-4228 pulls in better analog broadcast and has a bit more signal but doesn't get all of digital. The Grabbit Ears loses one digital station outside. When on the amplifier the Grabbit Ears regains the lost channel, CM-4228 didn't.
Grabbit Ears inside works excellent with amplification, but recieves all channels without amplification (when positioned correctly).

Easy to use, small and copact, Grabbit Ears would be the perfect "travel-tenna" when on the road.

Wanna give them a try!
 

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