75 ohm terminals.
 

I have a little stereo in use in the cellar. The supplied aerial isn't
adequate, so I am going to run to a better aerial which is at least
above ground, if not roof mounted. On the back of the unit, the aerial
terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...20terminal.jpg

the image shows two screw connections. I was under the impression that
this style of fitting is for 300 ohm aerials, and that 75 ohms are
usually done via a round TV-style plug (Belling Lee?). However, I am
no expert...

What sort of aerial cable should I use for this job? Do I have to
source some flat cable? The supplied aerial is one of those T style
ribbon cables, the conductors approximately 1 centimetre apart. Or can
I simply use normal coax - if so, is it important to which screw the
centre wire & the screen go to?

Thanks (again) in advance,

David Paste.

75 ohm terminals.
 

"David Paste" wrote in message
...
I have a little stereo in use in the cellar. The supplied aerial
isn't
adequate, so I am going to run to a better aerial which is at
least
above ground, if not roof mounted. On the back of the unit, the
aerial
terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...20terminal.jpg

the image shows two screw connections. I was under the
impression that
this style of fitting is for 300 ohm aerials, and that 75 ohms
are
usually done via a round TV-style plug (Belling Lee?). However,
I am
no expert...

What sort of aerial cable should I use for this job? Do I have
to
source some flat cable? The supplied aerial is one of those T
style
ribbon cables, the conductors approximately 1 centimetre apart.
Or can
I simply use normal coax - if so, is it important to which
screw the
centre wire & the screen go to?

Thanks (again) in advance,

David Paste.



Core to either screw and screen to earth.


--
Woody

harrogate three at ntlworld dot com

75 ohm terminals.
 

David Paste wrote:

the aerial terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...20terminal.jpg

the image shows two screw connections. I was under the impression that
this style of fitting is for 300 ohm aerials

I'd tend to agree, you could get a balun like this

http://upload.wikimedia.org/wikipedi...px-Tvbalun.jpg

75 ohm terminals.
 

On 9 Aug, 22:55, "Woody" wrote:

Core to either screw and screen to earth.

Forgive my ignorance, but earth as in the earth wire in the mains plug
type earth?

75 ohm terminals.
 

On 9 Aug, 22:59, Andy Burns wrote:

I'd tend to agree, you could get a balun like this

http://upload.wikimedia.org/wikipedi...b/Tvbalun.jpg/...

Thanks. Would this device attenuate the signal to any significant
degree?

75 ohm terminals.
 

On Aug 9, 10:53*pm, David Paste wrote:
I have a little stereo in use in the cellar. The supplied aerial isn't
adequate, so I am going to run to a better aerial which is at least
above ground, if not roof mounted. On the back of the unit, the aerial
terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...Fc/D_f8O4ukFZU...

the image shows two screw connections. I was under the impression that
this style of fitting is for 300 ohm aerials, and that 75 ohms are
usually done via a round TV-style plug (Belling Lee?). However, I am
no expert...

What sort of aerial cable should I use for this job? Do I have to
source some flat cable? The supplied aerial is one of those T style
ribbon cables, the conductors approximately 1 centimetre apart. Or can
I simply use normal coax - if so, is it important to which screw the
centre wire & the screen go to?

Thanks (again) in advance,

David Paste.

Inner coax to the top screw, braid to the bottom screw, the one with
the ground symbol. No need to actually ground anything. Chances are
the receiver will work with 75ohm unbalanced feeder (coax) despite
having terminals that suggest a balanced input. Of course the supplied
T aerial has 75ohm balanced feeder, but don't worry.

I have encountered receivers where the thing works better with the
coax connections reversed, and also ones where they work better with
the braid unconnected. Also ones that seem to ignore any external
connection!

Bill

75 ohm terminals.
 

On 9 Aug, 23:51, "
wrote:
On Aug 9, 10:53*pm, David Paste wrote:



I have a little stereo in use in the cellar. The supplied aerial isn't
adequate, so I am going to run to a better aerial which is at least
above ground, if not roof mounted. On the back of the unit, the aerial
terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...Fc/D_f8O4ukFZU...

the image shows two screw connections. I was under the impression that
this style of fitting is for 300 ohm aerials, and that 75 ohms are
usually done via a round TV-style plug (Belling Lee?). However, I am
no expert...

What sort of aerial cable should I use for this job? Do I have to
source some flat cable? The supplied aerial is one of those T style
ribbon cables, the conductors approximately 1 centimetre apart. Or can
I simply use normal coax - if so, is it important to which screw the
centre wire & the screen go to?

Thanks (again) in advance,

David Paste.

Inner coax to the top screw, braid to the bottom screw, the one with
the ground symbol. No need to actually ground anything.

OK, thanks. I was unsure if the earth image was associated solely with
the bottom screw, or if it was just part of the whole image.

Chances are
the receiver will work with 75ohm unbalanced feeder (coax) despite
having terminals that suggest a balanced input. Of course the supplied
T aerial has 75ohm balanced feeder, but don't worry.

I have encountered receivers where the thing works better with the
coax connections reversed, and also ones where they work better with
the braid unconnected. Also ones that seem to ignore any external
connection!

This is just a junky little Samsung MM-L2 I bought a few years ago to
plug the computer into, but I have spent too much time listening to
very hissy radio which has finally goaded me into action!

75 ohm terminals.
 

David Paste said...

This is just a junky little Samsung MM-L2 I bought a few years ago to
plug the computer into, but I have spent too much time listening to
very hissy radio which has finally goaded me into action!

Screw type terminals and F sockets for 75ohm FM aerial connections are
common nearly everywhere but the UK. http://goo.gl/mmpz

Here we stick with the a reversed coax Belling Lee type, requiring a
female connector on the FM downlead. Presumably this is to stop us
connecting the the radio aerial to the telly and vice versa.

A quite efficient and very cheap dipole FM or DAB aerial can be made
from a length of coax cable. Remove 29" (or adjust to suit the
frequency of your favourite station http://goo.gl/mhp8 ) of the outer
covering, carefully wriggle the inner insulated conductor out of the
braid. Arrange in a T shape and fasten to a handy bit of wood or
plastic. It works well as the only joint is where it connects to the
input.

Here's a picture of my efforts.
http://unsteadyken.posterous.com/

--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

75 ohm terminals.
 

Well, almost anything will work. it needs a balun/ transformer there. I seem
to recall making one that worked quite well using a length of coax but the
details are lost in the mists of time. I needed an earth though as the
standard connection was balanced 300 ohms.
In practice though, you can do all sorts of things and get away with it. As
long as you keep the ribbon cable clear of things, you can use a longer
length of it to the aerial, wich can be made into the folded dipole shape
and hung outside.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
Blind user, so no pictures please!
"Woody" wrote in message
news:[email protected]
"David Paste" wrote in message
...
I have a little stereo in use in the cellar. The supplied aerial isn't
adequate, so I am going to run to a better aerial which is at least
above ground, if not roof mounted. On the back of the unit, the aerial
terminal is as illustrated:

http://lh3.ggpht.com/_KFgaGzmhiUk/TG...20terminal.jpg

the image shows two screw connections. I was under the impression that
this style of fitting is for 300 ohm aerials, and that 75 ohms are
usually done via a round TV-style plug (Belling Lee?). However, I am
no expert...

What sort of aerial cable should I use for this job? Do I have to
source some flat cable? The supplied aerial is one of those T style
ribbon cables, the conductors approximately 1 centimetre apart. Or can
I simply use normal coax - if so, is it important to which screw the
centre wire & the screen go to?

Thanks (again) in advance,

David Paste.



Core to either screw and screen to earth.


--
Woody

harrogate three at ntlworld dot com

75 ohm terminals.
 

On Tue, 10 Aug 2010 02:43:28 +0100, UnsteadyKen
wrote:

Here we stick with the a reversed coax Belling Lee type, requiring a
female connector on the FM downlead. Presumably this is to stop us
connecting the the radio aerial to the telly and vice versa.

I don't think I've ever come across that. The downlead on both FM and TV
aerials has required a male Belling and the FM and TV receivers have had
female Bellings.

--
Alan White
Mozilla Firefox and Forte Agent.
Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland.
Webcam and weather:- http://windycroft.co.uk/weather