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Antenna for FM Radio and TV


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I currently have one of those vertical griller type antennas pointed at Como South Yarra (in Melbourne). I presume this is a UHF antenna. I get excellent Digital TV reception (HD and SD) via my Nebula DigiTV card.

I have a splitter near the mast, and feed off a signal to my FM tuner. FM reception varies from very good to average with "sizzling" sounds.

Can you Antenna experts tell me:

1. Should I have a separate VHF Antenna on the same mast for my FM reception?

2. If so what antenna should I get and should this be pointed at Mt Dandenong? There may be some buildings partially blocking line of sight to Mt Dandenong.

3. Will I really get a major improvement in FM reception doing this?

Any help is appreciated.

Cheers

Ian M

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Maybe you should just save your money up for a DAB receiver ~ They are trialing it now AFAIK. I guess find out whether the stations you are interested in are going digital...

DAB isn't that great - if you go to the UK and listen to their DAB, you can hear compression artefacts all over the place. Most of the streams are very bandwidth starved - sounds horrible. No match for a good quality FM signal.

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ianmit,

As you said your TV reception is fine using a UHF phased array from the South Yarra Translators.

There is no FM translators on this site so you will have to use Mt Dandenong.

The only FM or TV channel 3-5 antennas I can find are Hills Y3/FM (3 element)(http://www.hillsantenna.com.au/catalog/VHFAntenna.pdf)

More sensitive in this order are ANFM5 (5 element) and ANTFM8 (8 element)

(www.naspl.com). You can use a VHF/UHF diplexer to connect the two antennas to the same downlead. You will need another diplexer to separate the signals again.

The hissing sound is due to a lack of signal. If the signal is distorted (not clear) it is due to reflected signals. Both of these effects are reduced by using a directional antenna.

George.

He said he has good reception of the South Yarra translators so why would he wish to buy another antenna and point it to Mt Dandenong for poorer TV reception?

joeybloggs,

For Digital Audio Broadcasting in Australia you will need a band 3 antenna or an antenna for 1.5 GHz.

AlanH

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Thanks very much Guys,

It looks like I shall need a 5 or 8 element yagi (I thought that was a mythical snowman :blink: ) pointed at Mt Dandenong probably in Vertical mode (As I listen to ABC FM 90% of time is this vertical correct?) on same mast as existing UHF antenna.

Which should be mounted above which? I would have thought the yagi as I am further from Mt Dandenong than Como.

I am inclined towards the NASI ANTFM8, though haven't checked price/availability yet. I would have preferred 75 ohm connection as I shall be leading in with RG6 cable. Are there losses converting from 300 ohm to 75 ohm connection. Is that what the Balun is for?

Cheers

Ian M

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The FM8 antennas have a folded dipole with a natural feed point impedance of 300 ohms balanced. Each of these is sold with a 4:1 balun giving a 75 ohms unbalanced output for you to connect your RG6 75 ohm coax.

BALUN= Balanced-Unbalanced

like MODEM= Modulator-Demodulator

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  • 3 weeks later...
I suggest using a LP345HV for digital TV, mounted horizontally

and for FM, a 2-3 element yagi, from DSE or Laceys, mounted vertically, yes two antennas.

I have a LP345HV for DTV and made a coaxial vertical dipole for FM,  all works a treat.  http://www.dtvforum.info/index.php?showtopic=6571&hl=

The LP345 is not the best choice for digital TV reception from Como. Como transmits on UHF band 5 only and is vertically polarised not horizontal.

Ring Laceys TV in Frankston.

John Gemmell

www.jlgcommunications.com.au

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  • 2 weeks later...

to answer your question....

the best thing you could do would be to mix in a dedicated FM antenna, mounted VERTICALLY, with your phased array antenna, and then de-couple it at your receiver....

Call Laceys in Frankston... they sell the FM/TV mixers as well as FM antennas

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Merman,

Why do you want to put the antenna vertically. The transmitter uses both horizontal and vertical polarisation. If the receiving antenna is mounted vertically it will focus in the vertical direction preventing reflections from the sky! If it is mounted horizontally it will reject signals from adjacent buildings etc. Additional signals will either cause noise or distortion/loss of separation.

AlanH

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  • 3 weeks later...

Guys,

A dedicated FM antenna like the Fracarro 2FM works better than anything that is a general VHF antenna.

You mount it vertcally as this favors the weaker stations that are harder to get. Also mounted vertically much of the directionalty (experienced when antenna mounted horizontally) is lost but pointing the antenna towards the weak transmitter can help whilst lifting thoseweaker stations that have transmitters that can be anyplace. All the strong MtD. transmitters are still really strong. Clear as mud?

I put one on my house counted 50 FM stations from all over Victoria. Distortion, loss of separation? No such problems. Really difficult areas? Try the Fracarro 5FM - Laceys.tv in Frankston. And you put it as high as possible - don't forget height is might!

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poidahl,

ianmit wants to only receive ABC FM from Mt Dandenong. The more directional the antenna the less the noise, distortion and separation.

He would not have asked the question if buildings were not obstructing his signal.

You need to learn more about FM theory. The distortion and loss of separation are caused by reflected signals. The lack of signal strength when the signal level is under limiting causes hissing particularly on the L=R signal.

Lastly I recommeded an 8 element FM antenna which is designed for 88-108 MHz which is more sensitive than that sold by Laceys.

AlanH

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Alan, please don't get angry with me!

If ianmit has trouble with MtD. FM, your suggestion is good. If not and you are interested in the 50 odd stations possible including Mt.D, I stand by my suggestion! 2FM and 5FM are proper B2 antennas that incorporate a balun and have been proven as an excellent FM antenna horizontal or vertically polarized.

Why do you say the 8 element is more sensitive than the 5FM? Have you compared them?? Element count is not as important as antenna design.

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