Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Analog UHF TV signal reception improvement idea

Status
Not open for further replies.

HSter

New Member
Hi

Will the signal reception of analog TV improve by connecting several 'rabbit ear' TV antennas to form an array, (in parallel)? instead of using just one.

Thanks
 
Analog TV broadcasts will be gone in a couple of months in the US and in 2011 in Canada.

Rabbit ears are pretty lousy, a high up Bowtie or Yagi will help.
 
Last edited:
Hi

Will the signal reception of analog TV improve by connecting several 'rabbit ear' TV antennas to form an array, (in parallel)? instead of using just one.

Thanks

Antenna design is a form of "Black Magic".....so the answer would be, yes, maybe, it depends......

What continent do you live on?
 
Rabbit ears are horrible antennas. If you're having trouble with TV reception try something directional like a biquid or a yagi. A good biquad will give you 400% gain over bunny ears at the cost of it being a directional antenna, and if tuned for the center of your channel space should cover it all fairly well.
 
Analog TV broadcasts will be gone in a couple of months in the US and in 2011 in Canada.

What continent do you live on?

I live in Nigeria, West Africa. Analog TV is still widely used down here.

1. What should be the spacing between the 'elements'/individual rabbit ears? or how do i calculate this?

2. The rabbit ears have to be mounted outdoors, and i've got coax cable to wire the ant. to TV. so will this DIY balun work: **broken link removed**
For UHF channel 32 (f=581MHz), the coax balun is 12.9cm (approx. 5 in.). Should I make it in form of a coil?

I am receiving some signal (video and audio) but is not clear. Also at present, I am using the rabbit ear & coax transmission line without a balun.:eek:

Thanks
 
Last edited:
I don't know why blueroom brought up the analog vs digital, they use the same antennas =) The broadcast frequency bands aren't changing.

Give some serious thought to a directional antenna, you'd have to put it on the outside of the house due to size and you get better reception then anyways, but you'll get channels significantly stronger and from further away than with a pair of bunny ears.
 
Thanks Sceadwian. Which is the easiest to build, since I already receive some signals.
I can go out & buy one but, I prefer to learn and DIY it myself.
 
I've never tried to make one for UHF before but I've been a fan of the biquad antenna design in theory over the yagi because they're easier to make.

I've attached a PDF which contains the schematics for a 2.4ghz biquad (wifi) but it has the equation for calculating the size of the elements for any frequency. It's not in English but the graphics are self explanatory.

You don't need all four elements to get a decent antenna and it'd probably take up too much space at 500mhz so just only do one element. It's supposed to have a wide bandwidth but I don't know how wide so chose the center frequency carefully.
 

Attachments

  • Hybrid-Double-Quad-Array-D.pdf
    242 KB · Views: 428
HSter - take a look at amateur radio publications. While not the only source of information, the publications are often aimed at a broad audience (many with little experience or theoretical knowledge) and people who like to build their own stuff.

Best of luck to you.
 
Guys!...guys!...come on...we have a excellent opportunity to see something absolutely rediculous here....now follow my lead...

Yes, absolutely!...great idea!...now run out, and buy 1000 rabbbit ear antennas, connect them all together, and you will get 1000 times better receiption than with 1 lousy antenna....OBVIOUSLY!
BE CERTAIN TO TAKE A PICTURE OF THIS, and post it here!.


oooh ...taking advantage of 3rd world countries is soooo fun!
 
Last edited:
Guys!...guys!...come on...we have a excellent opportunity to see something absolutely rediculous here....now follow my lead...

Yes, absolutely!...great idea!...now run out, and buy 1000 rabbbit ear antennas, connect them all together, and you will get 1000 times better receiption than with 1 lousy antenna....OBVIOUSLY!
BE CERTAIN TO TAKE A PICTURE OF THIS, and post it here!.


oooh ...taking advantage of 3rd world countries is soooo fun!

bigkim100 = sarcastic smart aleck, noted.
 
Last edited:
My questions are:
1. Does anyone know what is the effect of thecoax balun wound in form of a coil cut to the right frequency?

2. Does anyone here know what is the way to determine separation of the elements in the design of the multi 'rabbit ear' array, in order to prevent parasitic interference?

Thanq ...
 
Last edited:
Won't the effective impedance drop when similar elements are connected in parallel to form an array. Much like resistors connected in parallel?:) ...
 
Last edited:
Like I said rabbit ears won't pick up those far away stations. A bowtie can be built with little more than scrap coat hangers, tinfoil & wood (plus a balun)
 
Thanks blueroomelectronics for your response.

what do you think about the assumption above regarding effective impedance?
 
Last edited:
If the above is correct, using 4 elements implies that there is no need for a balun since 300/4 = 75 ohms, the characteristic impedance of the coax transmission line. Right? :)
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top