Jump to content


Photo

Anyway To Modify Rabbit Ears To Increase Their Sensititivty?


  • Please log in to reply
13 replies to this topic

#1 pengoau

pengoau

    AV Forum Member

  • Member
  • 43 posts

Posted 01 August 2008 - 09:55 PM

G'day

I'm having ongoing problems with my rabbit ears and digital TV and just wondering is there any simply ways to make rabbit ears work better? What if I wrap the metal stalks in aluminum foil, would this increase its sensitivity? What if I attach a metal hanger? Should I make a rectangle or square of cardboard and cover it aluminium and stick it to the end of the aerial stalks? E.g:

Cardboard covered in aluminium foil on top of stalks.

Or another idea is to improve (?) on the above and on the front and back of the larger surface area (front/back) of the rectangle cover it with fly screen mesh? Should this catch and transmit more of the signal?

The only thing I've found that makes its reception better is ME, if I touch the damn thing it clears up LOL.

Also if I sit in certain positions on my couch it seems to affect the signal too lol...

I've played with orientation and elevation of the thing and positioning of the stalks, and found channel 7 and nine to be problematic (either no signal or breakup of the signal). Channel Ten, ABC and SBS seem to be fine. Otherwise if I get Chan 7 & 9 working then ABC, SBS and TEN stop working. So its either 7 & 9 working as one group and 10, ABC, SBS as the other group, if one group works the other doesn't. I can't seem to get them all working.

I rent so I am restricted to an indoor antenna, as there is no tv point. Also my TV is near my computer and my unit is closed to a road that has medium level of traffic on it. MY indoor antenna is a cheap one and I doubt the lead is shielded. Tho like I said, if I hold the aerial stalks the signal cleans straight up so I think my signal strength is fine I just need to do something that absorbs/catches it better, I think?

Any tips??


Thanks

NB: My location is Moreland Rd in Brunswick West VIC [so you can appreciate the level of road traffic going past the place!], and I use a Teac SD STB.

Edited by pengoau, 01 August 2008 - 10:22 PM.


#2 Mr.Bitey

Mr.Bitey

    AV Forum Member

  • Senior Member
  • 7,832 posts

Posted 01 August 2008 - 10:17 PM

:o

Get a dick smith amplified indoor antenna $49 - if it doesnt improove things, take it back for a refund.

Seriously, tho unless you can phsycially see (direct line of sight) the transmitted, rabbit ears dont work very well, and will pick up ALL the interference known to man.

If you MUST use them :rolleyes: try extending each arm 30cm horozontally (not poining up at all) so theyre both flat... going out to the sides...

Isnt there a bookcase nearby you can stick the antenna on at least? - get it away from your PC :)

Cheers,
Bitey

#3 Deaf Bhoy

Deaf Bhoy

    AV Forum Member

  • Member
  • PipPipPipPipPipPip
  • 2,300 posts

Posted 01 August 2008 - 10:37 PM

It obviously depends on where yer living but I've managed to get good results with rabbit ears in the past. Try getin a longer antenna lead attach it to the rabbit ears and then move around the room to try find the best spot maybe even out the window almost like an outdoor antenna. B)

Usually the lead that comes with the rabbit ears ain't long enough to get a good result. ;)

#4 Mr.Bitey

Mr.Bitey

    AV Forum Member

  • Senior Member
  • 7,832 posts

Posted 01 August 2008 - 10:42 PM

U can get good results with the rabbit ears - all my digital TV comes from rabbit ears and my HD is from a broken spiral antenna thats shoved on the floor in the corner of the room behing a speaker :D

Cheers,
Bitey

#5 beeblebrox

beeblebrox

    AV Forum Member

  • Member
  • PipPipPipPipPip
  • 1,561 posts

Posted 01 August 2008 - 10:45 PM

G'day

I'm having ongoing problems with my rabbit ears and digital TV and just wondering is there any simply ways to make rabbit ears work better? What if I wrap the metal stalks in aluminum foil, would this increase its sensitivity? What if I attach a metal hanger? Should I make a rectangle or square of cardboard and cover it aluminium and stick it to the end of the aerial stalks? E.g:

Cardboard covered in aluminium foil on top of stalks.

Or another idea is to improve (?) on the above and on the front and back of the larger surface area (front/back) of the rectangle cover it with fly screen mesh? Should this catch and transmit more of the signal?

The only thing I've found that makes its reception better is ME, if I touch the damn thing it clears up LOL.

Also if I sit in certain positions on my couch it seems to affect the signal too lol...

I've played with orientation and elevation of the thing and positioning of the stalks, and found channel 7 and nine to be problematic (either no signal or breakup of the signal). Channel Ten, ABC and SBS seem to be fine. Otherwise if I get Chan 7 & 9 working then ABC, SBS and TEN stop working. So its either 7 & 9 working as one group and 10, ABC, SBS as the other group, if one group works the other doesn't. I can't seem to get them all working.

I rent so I am restricted to an indoor antenna, as there is no tv point. Also my TV is near my computer and my unit is closed to a road that has medium level of traffic on it. MY indoor antenna is a cheap one and I doubt the lead is shielded. Tho like I said, if I hold the aerial stalks the signal cleans straight up so I think my signal strength is fine I just need to do something that absorbs/catches it better, I think?

Any tips??


Thanks

NB: My location is Moreland Rd in Brunswick West VIC [so you can appreciate the level of road traffic going past the place!], and I use a Teac SD STB.

Even renters can put up an external antenna which can be reasonably easy to remove when you move out.

If rabbit eats won't work the fancier versions usually won't work any differently.

Most of Moreland road is ok unless you get down towards the freeway.. I'd try hanging you rabbit ears out the window.

Edited by beeblebrox, 01 August 2008 - 10:46 PM.


#6 alanh

alanh

    AV Forum Member

  • Senior Member
  • 12,665 posts

Posted 01 August 2008 - 10:49 PM

pengoau,
You do not say where you are so...
Go to the Geographic Viewers’ Forum, which is near the bottom of the main forum’s home page. Select your region and read the pinned post “Get the Best Reception”. Please post any further correspondence in that strand for all in your region to see. I will see it anyway. You could also search your location in that strand for others in your area.

You need to do this to find out if there are repeaters on different channels in your area.
There is a link to indoor antennas for the best internal results.

AlanH

#7 pengoau

pengoau

    AV Forum Member

  • Member
  • 43 posts

Posted 02 August 2008 - 12:09 AM

Usually the lead that comes with the rabbit ears ain't long enough to get a good result. ;)


Yeah I am using the cable connected to the rabbit ears, its about half a metre. I guess I should get a longer cable.


Most of Moreland road is ok unless you get down towards the freeway.. I'd try hanging you rabbit ears out the window.


Not going to post my place's number, but I'm closer to the freeway than melville rd and moreland rd intersection. Can't hang them out the window 1) Its too noisy with the widow open 2) Its too cold.

pengoau,
You do not say where you are so...
AlanH


Do you know how rude you are coming off? Coz if you would care to actually read my post.... but since its seems to be too much effort, my location is at the end. Also this post is after general advice on how to improve performance for rabbit ears. I'm not after specific geographic advice otherwise I would have posted in the area of the forum for that.

FYI - I'm using Mt Dandenong, I can't pickup South Yarra at all.

Edited by pengoau, 02 August 2008 - 01:32 AM.


#8 mtv

mtv

    AV Forum Member

  • Senior Member
  • 6,047 posts

Posted 02 August 2008 - 12:26 AM

If you are in a part of Moreland Rd with tram lines, impulse noise interference can cause loss of reception.

Indoor antennas of all varieties are only as good as the signals available at the location.

The more obstacles in the signal-path, the less you are likely to get reliable digital reception.

As suggested, try moving the antenna around in the room... a good-quality (RG6 Quadshield) extension cable will help here.

Difficulty arises when you have channels on different bands (eg: VHF & UHF) as the antenna elements require to be adjusted to various lengths to match the various channels (frequencies).

In rental situations, often a small (outdoor) combination antenna, like the Fracarro LP34F will work much better indoors, than most rabbit ears type antennas.

#9 pengoau

pengoau

    AV Forum Member

  • Member
  • 43 posts

Posted 02 August 2008 - 01:34 AM

If you are in a part of Moreland Rd with tram lines, impulse noise interference can cause loss of reception.

Indoor antennas of all varieties are only as good as the signals available at the location.

The more obstacles in the signal-path, the less you are likely to get reliable digital reception.

As suggested, try moving the antenna around in the room... a good-quality (RG6 Quadshield) extension cable will help here.

Difficulty arises when you have channels on different bands (eg: VHF & UHF) as the antenna elements require to be adjusted to various lengths to match the various channels (frequencies).

In rental situations, often a small (outdoor) combination antenna, like the Fracarro LP34F will work much better indoors, than most rabbit ears type antennas.



No Tram lines on my part of morelabd road, I'm closer to the freeway than to melville road and moreland road intersection where the tram line is (on melville road). look it up in google if you want a picture.

So no one has any knowledge to say if adding a messh/alo foil to the rabbit should improve things?

Edited by pengoau, 02 August 2008 - 03:10 AM.


#10 charlesc

charlesc

    AV Forum Member

  • Senior Member
  • 2,613 posts

Posted 02 August 2008 - 04:32 PM

So no one has any knowledge to say if adding a messh/alo foil to the rabbit should improve things?

I think it is unlikely, in particular on simple rabitt's ears.

It's true, by the way, that metal objects can at times be added to the end of antenna elements. These are called 'capacitance hats', and can take the form of a cross, loop, ball, disk or just about anything conductive. They have the effect of making the element behave (to RF) as if it is in fact 10 - 30% longer than it is.
They can save space without reducing the peformance noticeably. It is uncommon to find them used with TV antennas though, space isn't usually a problem up in the air.

As most rabbit's ears have an adjustable (telescopic) element which you tune to the (lowest) TV channels you want to receive, there would be little point in adding something like this.

#11 tek--

tek--

    AV Forum Member

  • New Member
  • 2 posts

Posted 11 August 2008 - 01:43 PM

In my experience, yes (I am in the outer Melbourne eastern suburbs, Vermont South).

I bought a Samsung 32" 4 Series LCDTV a few weeks ago, this is my first Digital experience. As I am stuck with an indoors antenna, at first hookup I was only getting around 50% on the signal strength meter for the in-built tuner, and bit error rates were occasionally coming up as 1 to 3 or sometimes higher (I am not sure in what units this measurement is). Also the sound would cut out and pop whenever the washing machine was on the agitation cycle.

After reading through the many many threads on this forum, I have deconstructed the rabbit ears antenna and soldered RG6 quad shielded cable directly into the guts of it. Everything was then neatly shrink wrapped and taped up. The Antenna is then mounted to the interior wall sitting on top centre of the window frame (South facing at the back of the house). The RG6 runs across the top of the frame, down the side, and plugs into the TV using an F59>PAL convertor plug. The cable run is about 4metres long. The antenna dipoles are extended to about 750mm each end, aligned horizontally (much experimentation was done to arrive at this).

Now, all channels (except SBS which is around 55%) I get at least 75% strength, with average around 85% and sometimes as high as 95%. BER is down to 0. Interference from the appliances is negligible. 6 meters of RG6 cost $18 from DSE which included the convertor plugs. I noted also that this cable came with ferrite cores clamped onto each end of the cable.

I'm really happy with the results and also wanted to say thankyou to all the contributors of this forum for the information I have found :)

#12 charlesc

charlesc

    AV Forum Member

  • Senior Member
  • 2,613 posts

Posted 11 August 2008 - 01:58 PM

...I have deconstructed the rabbit ears antenna and soldered RG6 quad shielded cable directly into the guts of it.
..Now, all channels (except SBS which is around 55%) I get at least 75% strength

As a matter of interest, what was the 'base' model indoor antenna you used to start off with? Jaycar, DSE, Crest?
It sounds like it just had the telescopic antenna part, not a UHF (for SBS) section to it.

Probably one of the best 'indoor' antennas (as noted before in a few posts on the forum, by a few of the member installers) are the compact Fracarro log periodics, intended for caravan applications. They are an outdoor antenna, that can be used inside if needed as they are not too big.

EDIT: Here is a pic (I'm not recommending buying from this place, BTW)

Edited by charlesc, 11 August 2008 - 02:03 PM.


#13 tek--

tek--

    AV Forum Member

  • New Member
  • 2 posts

Posted 11 August 2008 - 06:41 PM

The base antenna I'm pretty sure was from Jaycar; it was some time ago that I bought it and cannot remember. It is just 2 telescopic poles that was on pivots inside a solid base, looks identical to DSE item L4011. There was nothing inside the base except for the cable core and shield connecting to the poles, and looped through a small ferrite core.

I didn't actually know SBS was UHF, that would explain why the reception is not on par with the others. It never drops out though so I'm happy with it!

#14 alanh

alanh

    AV Forum Member

  • Senior Member
  • 12,665 posts

Posted 11 August 2008 - 09:34 PM

All trying to increase the performance of indoor antennas,

The length of the arms should be related to the TV channels used. The location in the room with respect to conductive objects is critical. So extending the cable is a good idea so that the antenna can be away from the TV and computers and closer to an outside wall.

All twin arm antennas have identical performance for VHF. Although some have amplifiers, which can help or hinder.

For ideal lengths and other advice Go to the Geographic Viewers’ Forum, which is near the bottom of the main forum’s home page. Select your region and read the pinned post “Get the Best Reception”. Please post any further correspondence in that strand for all in your region to see. I will see it anyway. You could also search your location in that strand for others in your area.

This is important because the transmitter location and polarisation are critical. Within these posts is a link to indoor antennas with recommendations and more advice.

AlanH