What infection do I have?

[Rhonda]

Guys do I have some type of contagious infection you may catch?
Surely there is some expertise on this newsgroup to answer my question
below.
My area of electronics expertise is not in TV or RF and surely somebody here
can give me some assistance.
My area of expertise is in micro electronics in robotic and micro servo
construction and nuclear physics, and only to delighted to assist with any
questions in that area.

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.
Hunting around could not find any small 75 ohm flexible coax cable.

 

[Phil Allison]

"Rhonda"

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.

** A 3.5 mm jack - for the *RF* input ????

A you certain of that ??

7 inch LCD screens are all video monitors AFAIK.




............ Phil

 

[Mark Little]

Hi Rhonda,
You might like to try
http://www.belden.com.au/beldencatalogue/PDFS_links%20to%20docs/12_Broadcast/12.40_12.46.pdf

Mark


"Rhonda" <rhondadoesnot@likespam.com> wrote in message
news:UDJPc.30566$K53.15792@news-server.bigpond.net.au...

Guys do I have some type of contagious infection you may catch?
Surely there is some expertise on this newsgroup to answer my question
below.
My area of electronics expertise is not in TV or RF and surely somebody
here
can give me some assistance.
My area of expertise is in micro electronics in robotic and micro servo
construction and nuclear physics, and only to delighted to assist with any
questions in that area.

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.
Hunting around could not find any small 75 ohm flexible coax cable.

 

[Rhonda]

Phil http://www.lenoxx.com.hk/products/la666.htm
these come with a 3.5mm jack to a standard Belden PAL connector.
All the small TV like the Casio and DSE all have the 3.5mm jack for the
aerial socket.

Mark thank you for that link to the Belden PDF but there is nothing there
that is small and flexible.

What actually is 75 ohm coax? Where does the 75 ohm come into the scheme of
things?

DSE actually sell an adaptor that goes from the standard Belden PAL
connector to the 3.5mm jack for TV RF. Could not find the part number
quickly on the DSE website.


"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2n99k7Ftlq75U1@uni-berlin.de...

"Rhonda"

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can
you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.



** A 3.5 mm jack - for the *RF* input ????

A you certain of that ??

7 inch LCD screens are all video monitors AFAIK.




........... Phil

 

[Peter Parker]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2n99k7Ftlq75U1@uni-berlin.de...

** A 3.5 mm jack - for the *RF* input ????

Some small TVs do.

There's also adaptors so you can connect a standard TV antenna cable to them
(eg DSE P2035).

http://www.dse.com.au/cgi-bin/dse.storefront/410f7819022ef442273fc0a87f9c06b
3/Product/View/P2035

Peter

 

[Ross Herbert]

On Tue, 03 Aug 2004 11:24:56 GMT, "Rhonda"
<rhondadoesnot@likespam.com> wrote:

|Phil http://www.lenoxx.com.hk/products/la666.htm
|these come with a 3.5mm jack to a standard Belden PAL connector.
|All the small TV like the Casio and DSE all have the 3.5mm jack for the
|aerial socket.
|
|Mark thank you for that link to the Belden PDF but there is nothing there
|that is small and flexible.
|
|What actually is 75 ohm coax? Where does the 75 ohm come into the scheme of

See http://home.mira.net/~marcop/ciocahalf.htm

Have you asked the supplier of the LA666 for a cable or their
recommendation where to obtain one? After all, they sell the units so
they must know what cables and connectors to supply.

Ross H

 

[atec]

Rhonda wrote:

Phil http://www.lenoxx.com.hk/products/la666.htm
these come with a 3.5mm jack to a standard Belden PAL connector.
All the small TV like the Casio and DSE all have the 3.5mm jack for the
aerial socket.

Mark thank you for that link to the Belden PDF but there is nothing there
that is small and flexible.

What actually is 75 ohm coax? Where does the 75 ohm come into the scheme of
things?
nominal impedance . assume for normal purposes its a 75 ohm load.

DSE actually sell an adaptor that goes from the standard Belden PAL
connector to the 3.5mm jack for TV RF. Could not find the part number
quickly on the DSE website.

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2n99k7Ftlq75U1@uni-berlin.de...

"Rhonda"

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can
you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.



** A 3.5 mm jack - for the *RF* input ????

A you certain of that ??

7 inch LCD screens are all video monitors AFAIK.




........... Phil

--
X-No-Archive: Yes

 

[Phil Allison]

"Rhonda" <

Phil http://www.lenoxx.com.hk/products/la666.htm
these come with a 3.5mm jack to a standard Belden PAL connector.

** Then why are you asking about a special lead ??????

What actually is 75 ohm coax? Where does the 75 ohm come into the scheme
of
things?

* It is RF cable - ie it has very low power loss for signals in the HF,
VHF and UHF spectrum. 75 ohms is its characteristic impedance - see:
http://home.mira.net/~marcop/ciocahalf.htm Standard ( ie audio) shielded
cable will have huge losses at UHF signals.

Small diameter RF cables exist - DSE used to sell a 2mm dia Teflon
insulated one from Belden.




........... Phil

 

[Mark Little]

"Rhonda" <rhondadoesnot@likespam.com> wrote in message
news:cCKPc.30703$K53.24279@news-server.bigpond.net.au...

Phil http://www.lenoxx.com.hk/products/la666.htm
these come with a 3.5mm jack to a standard Belden PAL connector.
All the small TV like the Casio and DSE all have the 3.5mm jack for the
aerial socket.

Mark thank you for that link to the Belden PDF but there is nothing there
that is small and flexible.

I suggest that you look at the Conformable Coax Cable page 12.41, part
number 1672A. This is 75 Ohm coax with an outside diameter of 2.21mm. Having
a braided outer with a Teflon inner, it will be flexible. All of the cables
on this page could be used with a 3.5mm jack. The entry hole in the cover of
the 3.5mm jack normally has a diameter of about 5mm, so there are quite a
few cables in that brochure that would be suitable.

What actually is 75 ohm coax? Where does the 75 ohm come into the scheme
of
things?

Coax cable is simply a transmission line where one conductor surrounded by
another conductor such that the centre of the inner conductor and the centre
of the radius of the outer conductor are the same - co-axial. The outer
connector is connected to earth potential, so it essentially shields the
inner conductor.

The 75 Ohms refers to the characteristic impedance of the transmission line
formed by the coaxial cable. Once the cable is a few wavelengths long, the
characteristic impedance is constant, even though the end to end attenuation
is proportional to its length. The characteristic impedance of a cable
depends on the diameter of the inner, the separation between the inner and
outer and the dielectric constant of the material between the inner and
outer. If you do the maths, it can be shown that a characteristic impedance
of 77 Ohms gives the lowest attenuation, all other things being equal.

DSE actually sell an adaptor that goes from the standard Belden PAL
connector to the 3.5mm jack for TV RF. Could not find the part number
quickly on the DSE website.

I haven't seen a 3.5mm jack used for the TV RF. I suspect most other people
haven't either, which may account for the original lack of responses.

Mark

 

[Ross Herbert]

On Tue, 3 Aug 2004 21:38:22 +0930, "Mark Little" <mark@au.id.little>
wrote:

|
|"Rhonda" <rhondadoesnot@likespam.com> wrote in message
|news:cCKPc.30703$K53.24279@news-server.bigpond.net.au...
|> Phil http://www.lenoxx.com.hk/products/la666.htm
|> these come with a 3.5mm jack to a standard Belden PAL connector.
|> All the small TV like the Casio and DSE all have the 3.5mm jack for the
|> aerial socket.
|>
|> Mark thank you for that link to the Belden PDF but there is nothing there
|> that is small and flexible.
|
|I suggest that you look at the Conformable Coax Cable page 12.41, part
|number 1672A. This is 75 Ohm coax with an outside diameter of 2.21mm. Having
|a braided outer with a Teflon inner, it will be flexible. All of the cables
|on this page could be used with a 3.5mm jack. The entry hole in the cover of
|the 3.5mm jack normally has a diameter of about 5mm, so there are quite a
|few cables in that brochure that would be suitable.
|
My 2003 Belden catalogue shows 75 ohm conformable cable on 6.70 (p70
of 88). It is my opinion that "conformable" means semi-rigid or "hand
conformable". Theses cables are generally used in telecommunications
installations where the cables are meant to stay put but also be
semi-flexible. The centre conductor is therefore solid steel core
silver plated, hardly what Rhonda would be looking for I think.
Perhaps the analogue 75 ohm cable 9221 on 6.34 (p 34 of 88) would be
more suitable.

|> What actually is 75 ohm coax? Where does the 75 ohm come into the scheme
|of
|> things?
|
|Coax cable is simply a transmission line where one conductor surrounded by
|another conductor such that the centre of the inner conductor and the centre
|of the radius of the outer conductor are the same - co-axial. The outer
|connector is connected to earth potential, so it essentially shields the
|inner conductor.
|
|The 75 Ohms refers to the characteristic impedance of the transmission line
|formed by the coaxial cable. Once the cable is a few wavelengths long, the
|characteristic impedance is constant, even though the end to end attenuation
|is proportional to its length. The characteristic impedance of a cable
|depends on the diameter of the inner, the separation between the inner and
|outer and the dielectric constant of the material between the inner and
|outer. If you do the maths, it can be shown that a characteristic impedance
|of 77 Ohms gives the lowest attenuation, all other things being equal.
|
|> DSE actually sell an adaptor that goes from the standard Belden PAL
|> connector to the 3.5mm jack for TV RF. Could not find the part number
|> quickly on the DSE website.
|
|I haven't seen a 3.5mm jack used for the TV RF. I suspect most other people
|haven't either, which may account for the original lack of responses.
|
|Mark
|

 

[Mark Little]

"Ross Herbert" <rherber1SPAMEX@bigpond.net.au> wrote in message
news:f61vg015t0uklonv1dk5olcvlonj1aonhd@4ax.com...

On Tue, 3 Aug 2004 21:38:22 +0930, "Mark Little" <mark@au.id.little
wrote:
|I suggest that you look at the Conformable Coax Cable page 12.41, part
|number 1672A. This is 75 Ohm coax with an outside diameter of 2.21mm.
Having
|a braided outer with a Teflon inner, it will be flexible. All of the
cables
|on this page could be used with a 3.5mm jack. The entry hole in the cover
of
|the 3.5mm jack normally has a diameter of about 5mm, so there are quite a
|few cables in that brochure that would be suitable.
|
My 2003 Belden catalogue shows 75 ohm conformable cable on 6.70 (p70
of 88). It is my opinion that "conformable" means semi-rigid or "hand
conformable". Theses cables are generally used in telecommunications
installations where the cables are meant to stay put but also be
semi-flexible. The centre conductor is therefore solid steel core
silver plated, hardly what Rhonda would be looking for I think.
Perhaps the analogue 75 ohm cable 9221 on 6.34 (p 34 of 88) would be
more suitable.

Oops. You are dead right. The 9221 flexible cable is in the previous page
and has the braided inner.

Mark

 

[Adrian Jansen]

Yes it would be technically correct to use 75 ohm cable, to get correct
impedance matching. But if the cable run is 'reasonably short' and from an
amplifier, then you probably have plenty of signal level. Try it with
ordinary shielded audio cable, you wont do any damage. It might also work.
If it doesnt, then start looking around for better cable.

--
Regards,

Adrian Jansen
J & K MicroSystems
Microcomputer solutions for industrial control
"Rhonda" <rhondadoesnot@likespam.com> wrote in message
news:UDJPc.30566$K53.15792@news-server.bigpond.net.au...

Guys do I have some type of contagious infection you may catch?
Surely there is some expertise on this newsgroup to answer my question
below.
My area of electronics expertise is not in TV or RF and surely somebody
here
can give me some assistance.
My area of expertise is in micro electronics in robotic and micro servo
construction and nuclear physics, and only to delighted to assist with any
questions in that area.

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.
Hunting around could not find any small 75 ohm flexible coax cable.

 

[Martin]

"Rhonda" <rhondadoesnot@likespam.com> wrote in message
news:UDJPc.30566$K53.15792@news-server.bigpond.net.au...

Guys do I have some type of contagious infection you may catch?
Surely there is some expertise on this newsgroup to answer my question
below.
My area of electronics expertise is not in TV or RF and surely somebody
here
can give me some assistance.
My area of expertise is in micro electronics in robotic and micro servo
construction and nuclear physics, and only to delighted to assist with any
questions in that area.

My question is........
On a TV aerial system from an amplifier to the TV RF input socket, can you
use a piece of standard screen cable between the amplifier and TV.
The TV is a TFT 7" screen and the cable needs to be flexible, and it
terminates in a 3.5mm mini jack.
Hunting around could not find any small 75 ohm flexible coax cable.

Seems lots have given good info on 75 ohm cable, but you're original
question is still 'in the air', so to speak...

Bottom line - ordinary shielded cable will have massive signal losses at the
UHF frequencies used by TV, whereas proper 75 ohm co-ax (even the thin
flexible stuff) will have far less signal loss. Depending on how long the
cable run is, this may mean you have very low or no signal at the TV, or
reasonable signal, if you use standard cable.

You can try it if you like, but if you get low or poor signal you will need
to change to proper 75 ohm co-ax cable of some type. It wont damage
anything to use normal shielded cable, it just may mean you don't have a
good picture to watch!!

Cheers

Martin

 

[Phil Allison]

"Martin"

Seems lots have given good info on 75 ohm cable, but you're original
question is still 'in the air', so to speak...

So you missed my reply:

" ** It is RF cable - ie it has very low power loss for signals in the
HF,
VHF and UHF spectrum. 75 ohms is its characteristic impedance - see:
http://home.mira.net/~marcop/ciocahalf.htm Standard ( ie audio) shielded
cable will have huge losses at UHF signals. "

Bottom line - ordinary shielded cable will have massive signal losses at
the
UHF frequencies used by TV, whereas proper 75 ohm co-ax (even the thin
flexible stuff) will have far less signal loss.

** You are only 15 hours behind the game.




............ Phil

 

[Mitch]

I haven't seen a 3.5mm jack used for the TV RF. I suspect most other
people
haven't either, which may account for the original lack of responses.

Mark

I had a little casio LCD TV (5")
it used the 3.5mm for RF.
Came with an adaptor to change it to a normal beling lee type.

Mitch


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.733 / Virus Database: 487 - Release Date: 2/08/04

 

[Martin]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2nb0vsFv86dvU1@uni-berlin.de...

"Martin"


Seems lots have given good info on 75 ohm cable, but you're original
question is still 'in the air', so to speak...


So you missed my reply:

Yes - I usually just ignore your replies but this time I just plain missed
it ..... so sorry.....

" ** It is RF cable - ie it has very low power loss for signals in the
HF,
VHF and UHF spectrum. 75 ohms is its characteristic impedance - see:
http://home.mira.net/~marcop/ciocahalf.htm Standard ( ie audio) shielded
cable will have huge losses at UHF signals. "



Bottom line - ordinary shielded cable will have massive signal losses at
the
UHF frequencies used by TV, whereas proper 75 ohm co-ax (even the thin
flexible stuff) will have far less signal loss.



** You are only 15 hours behind the game.

Well, better late than never.. Some of us down here in the real world have
better things to do than sit and watch the newsgroups 24/7, so some replies
are unfortunately later than those without a life......

........... Phil

 

[Phil Allison]

"Martin" <...

"Phil Allison"

"Martin"


Seems lots have given good info on 75 ohm cable, but you're original
question is still 'in the air', so to speak...


So you missed my reply:

Yes - I usually just ignore your replies but this time I just plain missed
it ..... so sorry.....

** Commit ritual Seppuku anytime you like.



........... Phil

 

[Martin]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2nbkimFtntt2U1@uni-berlin.de...

"Martin" <...
"Phil Allison"

"Martin"


Seems lots have given good info on 75 ohm cable, but you're original
question is still 'in the air', so to speak...


So you missed my reply:

Yes - I usually just ignore your replies but this time I just plain
missed
it ..... so sorry.....




** Commit ritual Seppuku anytime you like.



.......... Phil

Now, now Aunty Phil, that's not very nice. Besides, I'm not Japanses and
really can't be bothered with all that formality.

Feel free to enage in whatever form of hara-kiri suits your needs if you
like........

 

[Rheilly Phoull]

"Martin" <vk2umjATyahooDOTcomDOTau> wrote in message
news:4110a7af_1@news.iprimus.com.au...

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:2nbkimFtntt2U1@uni-berlin.de...

"Martin" <...
"Phil Allison"

"Martin"


Seems lots have given good info on 75 ohm cable, but you're
original
question is still 'in the air', so to speak...


So you missed my reply:

Yes - I usually just ignore your replies but this time I just plain
missed
it ..... so sorry.....




** Commit ritual Seppuku anytime you like.



.......... Phil

Now, now Aunty Phil, that's not very nice. Besides, I'm not Japanses and
really can't be bothered with all that formality.

Feel free to enage in whatever form of hara-kiri suits your needs if you
like........


Well hat's off to Rhonda, she stimulated a response to a previously ignored

post very successfully.
Although for a qualified person having to ask that question seems strange.

--
Regards ........... Rheilly Phoull

 

[Franc Zabkar]

On Wed, 4 Aug 2004 19:40:17 +0800, "Rheilly Phoull"
<Rheilly@bigpong.com> put finger to keyboard and composed:

Well hat's off to Rhonda, she stimulated a response to a previously ignored
post very successfully.

To be fair, I doubt that the original post was *ignored*. It's just
that people missed the obvious solution (ie an adaptor) because the OP
had us thinking about cables.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.