Newbie FM tuner question

[Rob.]

Hi guys newbie question.
I just bought a Pioneer TX-710 Tuner.

I wanna hookup my FM Antenna properly.
Do I use the 300 ohm input or the 75 ohm input ?

heres a pic of the antenna I have

 

[mhardy6647]

what's your FM antenna?

If it terminates with twinlead, 300 ohm balanced is correct; if it terminates with coaxial cable, 75 ohm unbalanced is correct. The two classes of antenna termination may be interconverted with an inexpensive called a "balun" (BALanced-UNbalanced matching transformer). Radio Shack sells 'em.

 

[Rob.]

I have no idea what you are talking about.
The wire is sitting ontip of the tuner in the pic.
It comes out with 2 wires spread apart.

 

[mhardy6647]

Can't tell much from your photo, but based on the description that is a half-wave "T" dipole; it is a 300 ohm balanced antenna... and should be connected to the 300 ohm antenna input terminals on your tuner for best results.
http://www.electronics-radio.com/articles/radio/antennas/dipole/fm-dipole-antenna.php

 

[tomrich22]

That is a 300 ohm T antenna.....hook it to the 300 ohm imput. Then you will have to stretch it out in a T shape attached to the wall or the like.

 

[Rob.]

ok thanks.
Is it better reception than 75 ohm ?
What do I need to buy to use the 75 ohm input ? Can i see a pic of what I need ?

Also, what does the 'DE-EMPHASIS' swith do ?

 

[charles 1973]

I use a set of $20 rabbit ears from radio shack, it does a great job, looks nice, and is easy to turn for best reception. Use the 300 ohm input with the rabbit ears.

 

[Rob.]

I use a set of $20 rabbit ears from radio shack, it does a great job, looks nice, and is easy to turn for best reception.

what make is it ? got a pic ?

 

[Rob.]

Are these any good ?
It has a coaxial connector.
What do I need to hook it up to my Tuner ?

 

[charles 1973]

Are these any good ?
It has a coaxial connector.
What do I need to hook it up to my Tuner ?

It works for me. They smoked my $100 High end FM antenea. In fact I'm using that Antenae on a good FM Tuner in a deep basement right now. Brings in all local stations at 8.5 + signal, dead quiet. Even my AVR's cheap tuner works in the basement!

If all you have is 300 ohm screw terminals RS has a cheap adapter that a short 300 ohm cable connects to the Tuner, just tell them what you've got. Idealy an older antenae like this with 300 ohm leads. perhaps a friend or family member has an old VHF TV antenae you can use.
Rob's suggestion bellow is worth looking at, especially if it has a 300 ohm lead

 

[Rob.]

How about the Dynalab SR-100 Antenna ? Looks like a nice piece.

http://www.magnumdynalab.com/fmantennas-sr100.htm

 

[coonmanx]

I use the 300 ohm T-antenna with my NAD 7140 and it works just fine. I can actually get one station that I couldn't get before. With my Technics tuner I use the 75 ohm connection that is then hooked up to a rabbit ears which I have on the wall. It is coaxial all the way to the antenna so I don't need a balun for it. I bought the rabbit ears off of Ebay for just over $5.

http://www.ebay.com/itm/250809796822?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

If you hook up the T-antenna and it works well then I wouldn't bother with rabbit ears. But rabbit ears do work very well.

That Dynalab antenna got poor reviews on Amazon.

 

[Frank Sol]

IMO - the cheaper the Rabbit Ears the better they do as a FM antenna - no dials or switches and no loop

 

[wa2ise]

Often just a long length of wire, like 10 feet, connected to one of the terminals for 300 ohms, will work just fine. And a second length of wire connected to the other terminal will help too.

Often there are just too many variables in the reception physics of your home enviroment to make antenna design mean much, so quick and dirty approximations will work as well as a carefully designed antenna.

 

[uxwbill]

Also, what does the 'DE-EMPHASIS' swith do ?

A radio station can choose to "pre-emphasize" certain audio frequencies by way of a broadcast audio processor. This can "help" parts of the audio signal make it through the broadcasting process. The de-emphasis switch turns on a circuit that reverses this, in an effort to put the audio signal back the way it was before it was processed.

It may be intended for use on AM, FM or both bands.

You can set it to whichever mode you believe sounds better, though it's generally best if left on. Practically every radio station on the air today will use some form of pre-emphasis.

 

[amptramp]

ok thanks.
Is it better reception than 75 ohm ?
What do I need to buy to use the 75 ohm input ? Can i see a pic of what I need ?

Also, what does the 'DE-EMPHASIS' swith do ?

The noise increases as the modulating frequency increases with FM, so broadcasters increase the high frequencies at the broadcast transmitter (pre-emphasis) and the receiver is expected to perform a mirror-image reduction of high frequencies (de-emphasis) which also reduces the noise. A switch is often provided to select between 50 microsecond (European) and 75 microsecond (North American) de-emphasis time constants.

The antenna you have goes across the 300 ohm terminals.

 

[Rob.]

The noise increases as the modulating frequency increases with FM, so broadcasters increase the high frequencies at the broadcast transmitter (pre-emphasis) and the receiver is expected to perform a mirror-image reduction of high frequencies (de-emphasis) which also reduces the noise. A switch is often provided to select between 50 microsecond (European) and 75 microsecond (North American) de-emphasis time constants.

The antenna you have goes across the 300 ohm terminals.

Thanks. This clears things up

 

[vwestlife]

A radio station can choose to "pre-emphasize" certain audio frequencies by way of a broadcast audio processor. This can "help" parts of the audio signal make it through the broadcasting process. The de-emphasis switch turns on a circuit that reverses this, in an effort to put the audio signal back the way it was before it was processed.

Although not technically required by the FCC, the use of pre-emphasis on FM radio has been a de-facto standard since at least the 1950s. Many AM stations have also been using pre-emphasis since the late 1970s, and in fact U.S. stations broadcasting in AM Stereo, and all AM stations (mono or stereo) in Canada, are required to use the NRSC "modified 75 uS" pre-emphasis curve.

It may be intended for use on AM, FM or both bands.

The de-emphasis switch on the back of a tuner is designed for FM, however since many tuners run the AM audio through the FM Stereo decoder chip and de-emphasis (even though it's totally unnecessary and only degrades the sound), it may change the way AM sounds as well.

You can set it to whichever mode you believe sounds better, though it's generally best if left on. Practically every radio station on the air today will use some form of pre-emphasis.

75 uS pre/de-emphasis is the standard for North & South America and a few Pacific Rim countries (Thailand comes to mind, but I know there's a few others).

50 uS is used everywhere else: Europe, Africa, Australia, most of Asia, etc.

25 uS was designed to accomodate the use of Dolby FM, and is long since obsolete.

 

[musichal]

Often just a long length of wire, like 10 feet, connected to one of the terminals for 300 ohms, will work just fine. And a second length of wire connected to the other terminal will help too.

Often there are just too many variables in the reception physics of your home enviroment to make antenna design mean much, so quick and dirty approximations will work as well as a carefully designed antenna.

Yeah, I once lived in an apartment where dipoles and rabbit ears utterly failed to bring in the three stations I most wanted. They were blocked, and I had some pretty good tuners - there simply wasn't one spot that would work for all three stations. In frustration, I finally just ran almost ten feet of 300-ohm twin-lead horizontally across a wall (unseen) and voila! I got my stations cleanly. You just never know.

 

[vwestlife]

75 uS pre/de-emphasis is the standard for North & South America and a few Pacific Rim countries (Thailand comes to mind, but I know there's a few others).

Courtesy of Orban, here is the exact list:

75μs NORTH, CENTRAL, SOUTH AMERICA
50μs EUROPE, ASIA, AFRICA, PACIFICA
EXCEPT
75μs TAIWAN, KOREA, THAILAND