Jim GM4 DHJ ... wrote:
On 06/11/2020 18:47, charles wrote:
In article rir.org.uk,
Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops via
the coax cable that supplies the cable broadband signal. It might be what
everyone else calls a braid breaker.

Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Yes, the cable cabinet and the house might be on different phases.

thanks this seems to be the problem


You are even thicker than I thought possible.

On 06/11/2020 22:36, Radio Man wrote:
Jim GM4 DHJ ... wrote:
On 06/11/2020 18:47, charles wrote:
In article rir.org.uk,
Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops via
the coax cable that supplies the cable broadband signal. It might be what
everyone else calls a braid breaker.

Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Yes, the cable cabinet and the house might be on different phases.

thanks this seems to be the problem


You are even thicker than I thought possible.

you are a bit thick then....

On 06/11/2020 22:43, Brian Morrison wrote:
On Fri, 06 Nov 2020 20:38:46 +0000, The Natural Philosopher wrote:

On 06/11/2020 18:10, Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops
via the coax cable that supplies the cable broadband signal. It might
be what everyone else calls a braid breaker.

Gosh. Ground loops. 50hz hum on a megahertz signal...Do you folks over
on uk.radio.amateur actually have *any* electronic experience *at all*.?

Quite a lot actually, professional RF engineer for 40 odd years here.
Coupling between different signals can be problematic, I assume that the
cable people have a whole variety of kit to fix these issues. Jim has had
a fairly long time with the same ISP I think, so he may have a relatively
old installation that is a bit more sensitive to the exact topology
around and inside his house. It's not easy when you are constrained in
what can be fitted, cable internet is quite after-market in nature
certainly 25 years ago when a lot of it was initially fitted.


Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Jim clearly upset it initially and then fixed it again.

The right position is in the bin, along with his tinfoil hat and quartz
crystal pyramid knife sharpener

Sometimes TNP I see what makes so many cam.misc regulars find you
abrasive. This is one such occasion.

And Jim, you've suckered me into a cross-post to uk.d-i-y you old sod.

Haaaaaaaaaaaaaaa said you would

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"newshound" wrote in message
o.uk...
On 06/11/2020 11:52, jim.gm4dhj wrote:
where should the galvonic isolator be positioned in relation to a
virginmedia modem/router?.....I relocated the box to the upper floor of
the house using a good coax leaving the isolator down stairs this seemed
to cause problems with my internet connection idea why?

Depends on where you have the dilithium crystals.

Unfortunately, because the theory and the on the ground result often do not
match, I'd imagine.
Like balanced aerials and unbalanced tuners can work well but using a balun
often makes stuff worse. Its the great mystery of life, or at least one of
them. No I do not have a licence, but my late Father was friends with quite
a few.

I wonder what sort of Earth the guy has on his system.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Radio Man" wrote in message
...
Jim GM4DHJ ... wrote:
On 06/11/2020 15:07, Jim GM4 DHJ ... wrote:
On 06/11/2020 15:06, newshound wrote:
On 06/11/2020 14:35, Jim GM4DHJ ... wrote:
what a bunch of arseholes you three are.....

You can always count on Jim to "bite"!
and why not ...
you ask a simple question and all you get is a bunch of jokers....


Why does someone who passed the RAE need to ask.

On 7 Nov 2020 at 07:41:18 GMT, ""Brian Gaff \" Sofa\)"
wrote:

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

The merit of your ethernet solution is that it already has galvanic isolation.
Unless you use shielded ethernet cable, which is often counterproductive
unless the whole system is designed for it.

--
Roger Hayter

Roger Hayter wrote:
On 7 Nov 2020 at 07:41:18 GMT, ""Brian Gaff \" Sofa\)"
wrote:

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

The merit of your ethernet solution is that it already has galvanic isolation.
Unless you use shielded ethernet cable, which is often counterproductive
unless the whole system is designed for it.


Another one showing how little he knows.

Brian Morrison wrote:
On Fri, 06 Nov 2020 20:38:46 +0000, The Natural Philosopher wrote:

On 06/11/2020 18:10, Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops
via the coax cable that supplies the cable broadband signal. It might
be what everyone else calls a braid breaker.

Gosh. Ground loops. 50hz hum on a megahertz signal...Do you folks over
on uk.radio.amateur actually have *any* electronic experience *at all*.?

Quite a lot actually, professional RF engineer for 40 odd years here.
Coupling between different signals can be problematic, I assume that the
cable people have a whole variety of kit to fix these issues. Jim has had
a fairly long time with the same ISP I think, so he may have a relatively
old installation that is a bit more sensitive to the exact topology
around and inside his house. It's not easy when you are constrained in
what can be fitted, cable internet is quite after-market in nature
certainly 25 years ago when a lot of it was initially fitted.


Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Jim clearly upset it initially and then fixed it again.

The right position is in the bin, along with his tinfoil hat and quartz
crystal pyramid knife sharpener

Sometimes TNP I see what makes so many cam.misc regulars find you
abrasive. This is one such occasion.

And Jim, you've suckered me into a cross-post to uk.d-i-y you old sod.


For all of your claimed experience you have overlooked the most basic
question. What has changed recently to give him the problem. That is the
key.

On 06/11/2020 21:41, Tim+ wrote:
Ian Jackson wrote:
In message , charles
writes


But this might have failed in Jim's case. For my info - how does the phone
signal get past the blocking capacitor?

Virgin provides internet and TV at RF (5MHz to 1000+MHz, via coax) - and
I was assuming that that was what Jim was talking about. Phone will be
on twisted-pair phonelines.

Um, not in my house. Phone plugs into router (which only has a coax link to
the outside world).

Tim

IIRC phone is demodulated in the 'modem' from some sort of RF signal.


--
How fortunate for governments that the people they administer don't think.

Adolf Hitler

On 06/11/2020 22:43, Brian Morrison wrote:
On Fri, 06 Nov 2020 20:38:46 +0000, The Natural Philosopher wrote:

On 06/11/2020 18:10, Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops
via the coax cable that supplies the cable broadband signal. It might
be what everyone else calls a braid breaker.

Gosh. Ground loops. 50hz hum on a megahertz signal...Do you folks over
on uk.radio.amateur actually have *any* electronic experience *at all*.?

Quite a lot actually, professional RF engineer for 40 odd years here.
Coupling between different signals can be problematic, I assume that the
cable people have a whole variety of kit to fix these issues. Jim has had
a fairly long time with the same ISP I think, so he may have a relatively
old installation that is a bit more sensitive to the exact topology
around and inside his house. It's not easy when you are constrained in
what can be fitted, cable internet is quite after-market in nature
certainly 25 years ago when a lot of it was initially fitted.

The point is, that people who do electronics professionally, as I did
for many years, have been there, done that, got the T shirt and
automatically, simply as a way of reducing fault calls, isolated their
domestic kit that plugs into long lines, from any hard LF connection to
the ground. In ADSL it is conventional to have a ferrite balun IIRC. IN
CAR5 ethernet its all balanced mode anyway.

Look at Jims post. The term 'galvanic isolator' is misspelt for a start.
Secondly it is never used outside of a marine context where the point is
not to have boats floating in sea water 'earthed' to the earth and to
each other, to avoid *galvanic* corrosion.

It is never ever used by normal engineers to refer to not earthing
equipment for the avoidance of ground loops which are only relevant
anyway in the audio band. At RF there are a lot more weird effects that
come in, but earthing stuff doesn't normally make any difference.

So there are 3 solid hard reasons bound up with experience why Jim is in
fact talking through his arse.

1/. A 'galvanic isolator' is irrelevant outside of a marina.
2/. Ground loop seldom if ever have any effect at RF and above, which is
where cable operates.
3/. Despite their desire to make profits, manufacturers of electronic
kit in general make sure it works without the need for ancillary plug in
items.




Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Jim clearly upset it initially and then fixed it again.

The right position is in the bin, along with his tinfoil hat and quartz
crystal pyramid knife sharpener

Sometimes TNP I see what makes so many cam.misc regulars find you
abrasive. This is one such occasion.

Oh FFS. Intelligent lives matter. Do we have to pander to idiocy
everywhere, all the time?

If wannabe electronics engineers were just to actually learn the theory
and do some design, perhaps their little knowledge wouldn't be such a
dangerous thing.

And gold plated speaker wires, red sharpies to reduce CD distortion and
the like wouldn't be on sale.



--
How fortunate for governments that the people they administer don't think.

Adolf Hitler

On 7 Nov 2020 at 10:16:37 GMT, "The Natural Philosopher"
wrote:




Oh FFS. Intelligent lives matter. Do we have to pander to idiocy
everywhere, all the time?

If wannabe electronics engineers were just to actually learn the theory
and do some design, perhaps their little knowledge wouldn't be such a
dangerous thing.

And gold plated speaker wires, red sharpies to reduce CD distortion and
the like wouldn't be on sale.

I must say I assumed that Jim's "galvanic isolator" was something supplied by
(and named by!) Virgin Cable. I don't think he would have thought of it for
himself. Equally, I assumed the earth voltages were affecting the low level
digital circuits in his equipment rather than the RF parts. Obviously ICBW!

--
Roger Hayter

In article ,
charles wrote:
Interestingly, I had, in the analogue days, hum on my tv signal when it
rained. Took a bit of tracing: VCR had a potential on it's earth which
travelled up the downlead into my aerial combiner. When it rained it
found a path to earth down the wall. There was a drop of about 3v
between the output and input earths and this transferred itself to the
wanted signal and ended up on the picture. Solved by grounding the
input coax to the VCR.

Never quite understood how many co-ax socket screens are directly
connected to ground. Given the aerial doesn't need a DC path there.

--
*I never drink anything stronger than gin before breakfast *

Dave Plowman London SW
To e-mail, change noise into sound.

On 07/11/2020 09:53, Radio Man wrote:
Roger Hayter wrote:
On 7 Nov 2020 at 07:41:18 GMT, ""Brian Gaff \" Sofa\)"
wrote:

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

The merit of your ethernet solution is that it already has galvanic isolation.
Unless you use shielded ethernet cable, which is often counterproductive
unless the whole system is designed for it.


Another one showing how little he knows.

well help us out brian reay

On 07/11/2020 09:53, Radio Man wrote:
Brian Morrison wrote:
On Fri, 06 Nov 2020 20:38:46 +0000, The Natural Philosopher wrote:

On 06/11/2020 18:10, Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is one
doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops
via the coax cable that supplies the cable broadband signal. It might
be what everyone else calls a braid breaker.

Gosh. Ground loops. 50hz hum on a megahertz signal...Do you folks over
on uk.radio.amateur actually have *any* electronic experience *at all*.?

Quite a lot actually, professional RF engineer for 40 odd years here.
Coupling between different signals can be problematic, I assume that the
cable people have a whole variety of kit to fix these issues. Jim has had
a fairly long time with the same ISP I think, so he may have a relatively
old installation that is a bit more sensitive to the exact topology
around and inside his house. It's not easy when you are constrained in
what can be fitted, cable internet is quite after-market in nature
certainly 25 years ago when a lot of it was initially fitted.


Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Jim clearly upset it initially and then fixed it again.

The right position is in the bin, along with his tinfoil hat and quartz
crystal pyramid knife sharpener

Sometimes TNP I see what makes so many cam.misc regulars find you
abrasive. This is one such occasion.

And Jim, you've suckered me into a cross-post to uk.d-i-y you old sod.


For all of your claimed experience you have overlooked the most basic
question. What has changed recently to give him the problem. That is the
key.

indeed

On 07/11/2020 10:43, Roger Hayter wrote:
On 7 Nov 2020 at 10:16:37 GMT, "The Natural Philosopher"
wrote:




Oh FFS. Intelligent lives matter. Do we have to pander to idiocy
everywhere, all the time?

If wannabe electronics engineers were just to actually learn the theory
and do some design, perhaps their little knowledge wouldn't be such a
dangerous thing.

And gold plated speaker wires, red sharpies to reduce CD distortion and
the like wouldn't be on sale.

I must say I assumed that Jim's "galvanic isolator" was something supplied by
(and named by!) Virgin Cable. I don't think he would have thought of it for
himself. Equally, I assumed the earth voltages were affecting the low level
digital circuits in his equipment rather than the RF parts. Obviously ICBW!

indeed

Jim GM4 DHJ ... wrote:
On 07/11/2020 09:53, Radio Man wrote:
Roger Hayter wrote:
On 7 Nov 2020 at 07:41:18 GMT, ""Brian Gaff \" Sofa\)"
wrote:

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

The merit of your ethernet solution is that it already has galvanic isolation.
Unless you use shielded ethernet cable, which is often counterproductive
unless the whole system is designed for it.


Another one showing how little he knows.

well help us out brian reay


He probably would I wont.

On 07/11/2020 16:19, Radio Man wrote:
Jim GM4 DHJ ... wrote:
On 07/11/2020 09:53, Radio Man wrote:
Roger Hayter wrote:
On 7 Nov 2020 at 07:41:18 GMT, ""Brian Gaff \" Sofa\)"
wrote:

Well, surely the whole idea is to try to remove your transmitted signal from
the modem or anything connected to it. So for a start are you sure of the
mechanism its getting into? Generally, it seems if you live next door to a
ham and are on BT then its far more difficult than on virgin unless its
fibre to the home,
I would leave the Virgin hub where it is, make it into a modem only then buy
yourself a nice shine router and stick that on the end of a good quality
network cable. The wireless will be better and from tests someone I know
did, very little is getting back to the hub. It seems as you deduce that the
main problem is that the hub is fed by coax, and it is the sheath of this
which is picking up the signals. Its counter intuitive I know that bits of
open wire in a plastic bundle seem better than a screened cable, but proof
of pudding and eating, and you may have other issues, even the length of the
coax can cause issues if its a quarter wave at the transmitting frequency,
I'd imagine.
Back in the old CB days one used to use braid breakers on tvs, but I do not
know what effect that kind of device might have on a broadband signal, as by
definition it is,um broad band!

Brian

The merit of your ethernet solution is that it already has galvanic isolation.
Unless you use shielded ethernet cable, which is often counterproductive
unless the whole system is designed for it.


Another one showing how little he knows.

well help us out brian reay


He probably would I wont.

whatever you say brian ....

On 07/11/2020 17:34, Brian Morrison wrote:
On Sat, 07 Nov 2020 10:16:37 +0000, The Natural Philosopher wrote:

On 06/11/2020 22:43, Brian Morrison wrote:
On Fri, 06 Nov 2020 20:38:46 +0000, The Natural Philosopher wrote:

On 06/11/2020 18:10, Brian Morrison wrote:
On Fri, 06 Nov 2020 15:46:20 +0000, The Natural Philosopher wrote:

A galvanic isolator is a way to prevent corrosion in boats. WTF is
one doing in a Broadband setup?

It is used to disconnect the internal equipment from the external
broadband cabinet and equipment. It also acts to prevent ground loops
via the coax cable that supplies the cable broadband signal. It might
be what everyone else calls a braid breaker.

Gosh. Ground loops. 50hz hum on a megahertz signal...Do you folks over
on uk.radio.amateur actually have *any* electronic experience *at
all*.?

Quite a lot actually, professional RF engineer for 40 odd years here.
Coupling between different signals can be problematic, I assume that
the cable people have a whole variety of kit to fix these issues. Jim
has had a fairly long time with the same ISP I think, so he may have a
relatively old installation that is a bit more sensitive to the exact
topology around and inside his house. It's not easy when you are
constrained in what can be fitted, cable internet is quite after-market
in nature certainly 25 years ago when a lot of it was initially fitted.

The point is, that people who do electronics professionally, as I did
for many years, have been there, done that, got the T shirt and
automatically, simply as a way of reducing fault calls, isolated their
domestic kit that plugs into long lines, from any hard LF connection to
the ground. In ADSL it is conventional to have a ferrite balun IIRC. IN
CAR5 ethernet its all balanced mode anyway.

And generally it works. But twisted pair lines are more sensitive to
environment than coax, and are built to higher standards in general.
Especially in comparison with pre-2000 cable TV systems.


Look at Jims post. The term 'galvanic isolator' is misspelt for a start.
Secondly it is never used outside of a marine context where the point is
not to have boats floating in sea water 'earthed' to the earth and to
each other, to avoid *galvanic* corrosion.

I will admit that when I saw Jim's post, I did have to have a quick look
to see what he was referring to. As I said, braid breaker is the term
that is used in RF circles, and is mainly intended to avoid current
flowing on the outside of coax getting anywhere it's not wanted,
obviously the internal currents on coax matter but you rarely want the
outside current involved except in coax baluns.


It is never ever used by normal engineers to refer to not earthing
equipment for the avoidance of ground loops which are only relevant
anyway in the audio band. At RF there are a lot more weird effects that
come in, but earthing stuff doesn't normally make any difference.

Have a look he

https://www.dipolnet.com/galvanic_is...hz__R48605.htm

and he

https://www.amazon.co.uk/ASH-GISX101...or-TELESTE/dp/
B019EGL97S/ref=sr_1_fkmr1_2?
dchild=1&keywords=galvanic+isolator+cable+tv&qid=1 604769468&sr=8-2-fkmr1



So there are 3 solid hard reasons bound up with experience why Jim is in
fact talking through his arse.

1/. A 'galvanic isolator' is irrelevant outside of a marina.

See above. Terminology might not be to our taste, but it's what the
industry calls these things.

2/. Ground loop seldom if ever have any effect at RF and above, which is
where cable operates.

Depending on what is going on, it is possible for cable lengths to cause
notches within the desired passband if the grounding is imperfect or if
there is unintended inductance in ground paths. Cable TV is notorious for
this sort of effect.

3/. Despite their desire to make profits, manufacturers of electronic
kit in general make sure it works without the need for ancillary plug in
items.


Yes, but as I said in after-market equipment there are always a few odds
and sods that need mopping up. I would love to say that you're right and
nothing is needed, but then I've seen enough cable TV cabinets with
broken doors on the streets, and what lies within is quite horrifying to
anyone with even a faint interest in tidiness. The F connector, usually
screw on, is the absolute cheapest and nastiest RF connector in existence.




Putting it in the 'wrong' position might cause a change in SNR, that
depends on exact details of the property and wiring.

Jim clearly upset it initially and then fixed it again.

The right position is in the bin, along with his tinfoil hat and
quartz crystal pyramid knife sharpener

Sometimes TNP I see what makes so many cam.misc regulars find you
abrasive. This is one such occasion.

Oh FFS. Intelligent lives matter. Do we have to pander to idiocy
everywhere, all the time?

No, but if someone is asking about something that exists, and why it
might be problematic if disturbed, they deserve a fair hearing.


If wannabe electronics engineers were just to actually learn the theory
and do some design, perhaps their little knowledge wouldn't be such a
dangerous thing.

Jim is against professionals having radio as a hobby, so his preference
is not to be too technical. Amateur radio is a broad church.


And gold plated speaker wires, red sharpies to reduce CD distortion and
the like wouldn't be on sale.

Don't hold with any of those. All nonsense as you well know.

Right. No more uk.d-i-y for me forthwith.

good man...they are a bunch of *******.....

On 07/11/2020 17:34, Brian Morrison wrote:
On Sat, 07 Nov 2020 10:16:37 +0000, The Natural Philosopher wrote:



So there are 3 solid hard reasons bound up with experience why Jim is in
fact talking through his arse.

1/. A 'galvanic isolator' is irrelevant outside of a marina.

See above. Terminology might not be to our taste, but it's what the
industry calls these things.

2/. Ground loop seldom if ever have any effect at RF and above, which is
where cable operates.

Depending on what is going on, it is possible for cable lengths to cause
notches within the desired passband if the grounding is imperfect or if
there is unintended inductance in ground paths. Cable TV is notorious for
this sort of effect.

3/. Despite their desire to make profits, manufacturers of electronic
kit in general make sure it works without the need for ancillary plug in
items.


Yes, but as I said in after-market equipment there are always a few odds
and sods that need mopping up. I would love to say that you're right and
nothing is needed, but then I've seen enough cable TV cabinets with
broken doors on the streets, and what lies within is quite horrifying to
anyone with even a faint interest in tidiness. The F connector, usually
screw on, is the absolute cheapest and nastiest RF connector in existence.

Yes. I owe Jim an apology. The idiot here is not Jim, but Virgin, who have

(a) deigned to supply kit that was not fit for purpose ,

(b) added in a 'ground breaker' and called it by a misleading name
presumably for 'marketing purposes'

(c) not supplied simple instructions on where to put it.,

It is sad reflection when you look on approaching death with
equanimity, because at least the frightful incompetence you sought to
eradicate in every thing you did,and has achieved dominance in
professional areas, will be something you no longer have to deal with...

....Except no doubt St Peter will require two factor authorisation and a
printed electricity bill before letting me in the pearly gates, but the
computer system will be down and the backup system gone to the Devil.

:=)

--
"Strange as it seems, no amount of learning can cure stupidity, and
higher education positively fortifies it."

- Stephen Vizinczey

On 07/11/2020 17:54, The Natural Philosopher wrote:
On 07/11/2020 17:34, Brian Morrison wrote:
On Sat, 07 Nov 2020 10:16:37 +0000, The Natural Philosopher wrote:



So there are 3 solid hard reasons bound up with experience why Jim is in
fact talking through his arse.

1/. A 'galvanic isolator' is irrelevant outside of a marina.

See above. Terminology might not be to our taste, but it's what the
industry calls these things.

2/. Ground loop seldom if ever have any effect at RF and above, which is
where cable operates.

Depending on what is going on, it is possible for cable lengths to cause
notches within the desired passband if the grounding is imperfect or if
there is unintended inductance in ground paths. Cable TV is notorious for
this sort of effect.

3/. Despite their desire to make profits, manufacturers of electronic
kit in general make sure it works without the need for ancillary plug in
items.


Yes, but as I said in after-market equipment there are always a few odds
and sods that need mopping up. I would love to say that you're right and
nothing is needed, but then I've seen enough cable TV cabinets with
broken doors on the streets, and what lies within is quite horrifying to
anyone with even a faint interest in tidiness. The F connector, usually
screw on, is the absolute cheapest and nastiest RF connector in
existence.

Yes. I owe Jim an apology. The idiot here is not Jim, but Virgin, who have

(a) deigned to supply kit that was not fit for purpose ,

(b) added in a 'ground breaker' and called it by a misleading name
presumably for 'marketing purposes'

(c) not supplied simple instructions on where to put it.,

It isÂ* sad reflection when you look on approaching death with
equanimity, because at least the frightful incompetence you sought to
eradicate in every thing you did,and has achieved dominance in
professional areas, will be something you no longer have to deal with...

...Except no doubt St Peter will require two factor authorisation and a
printed electricity bill before letting me in the pearly gates, but the
computer system will be down and the backup system gone to the Devil.

:=)

oh dear