House of Horrors

"Bill Wright" wrote in message
...

"Mike" wrote in message
...
On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:
In either case the amp, which runs unattended in
the loft, has to be scrapped.



To try to trace such a fault on an inexpensive unit aint worth the effort.
To be quite honest, and as a consumer, I'd be more than happy for the unit
to be replaced under these circumstances.
As Bill says, for £25 or even £50 quid, it just aint worth the risk!

Can you image the scenerio after the loft caught fire and the questions the
installer would have to answer!

Just my two-penneth,

[email protected]

On Wed, 30 May 2007 00:49:11 +0100, Mike mused:

On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:

If I went into a loft and found a domestic distribution amplifier that was
dead I would test for a mains supply and if there was one I would scrap the
amp. I would bother checking whether someone had removed the fuse in the
plug top! The possibility of that is zero under normal circumstances,

Yes, agreed.

so it would be reasonable to assume that either the plug
top fuse had blown or the amp had an internal fault.

Correct

In either case the amp, which runs unattended in
the loft, has to be scrapped.

Utter drivel

How so? I come across similar situations from time to time, some items
are cheaper to replace at the first sign of trouble rather than keep
going back to them time after time, which either costs the customer or
you more and also akes you look incompetent.

It would be too risky to just change the fuse.

On what basis do you come to that conclusion?

Replace fuse, faulty amp takes it out agin the next morning, call out
2, repeat until fed up.

It would, in fact, be a seriously bad thing to do.

Why?

Generally it will have blown for a reason. If the fuse was open to the
air I would perhaps go on the view that over time some sort of
oxidation has occured but this is a sealed fuse, generally it won't
blow just because it's old.

So that part of the programme was ********.

And your post isn't?

It's a lot less ******** than yours.

Since they had the CAI on board I would have thought
they could have cooked up a better 'fault'. How about making it look as if
someone had put a heavy case in the loft and it had pulled the downlead out
of the amplifier's aerial socket? This is a common situation. Idiots!

Pity, I had thought more hightly of you and was considering putting
some work your way. On the basis of your posting I reckon you'd be
selling me oxygen free copper directional coax for a line of sight 10
miles from Emley aerial.

Now you're just being stupid.

P.S. Are you sure you weren't ****ed out of your skull when you
posted?

Ditto.
--
Regards,
Stuart.

In article ,
Prometheus wrote:
Fuses do fail with age; I have had a few which have failed after many
years operation, when I check the current consumption I find it to be as
expected, so I replace the failed fuse and the kit continues to work.

That can apply to a fuse working near its rated value - it continually
expands and contracts as it's powered up and down etc. A 3 amp fuse
feeding a DA might as well be a lump of solid brass as regards heating
effect.

--
*If vegetable oil comes from vegetables, where does baby oil come from? *

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

On Wed, 30 May 2007 00:49:11 +0100, Mike wrote:

On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:

If I went into a loft and found a domestic distribution amplifier that was
dead I would test for a mains supply and if there was one I would scrap the
amp. I would bother checking whether someone had removed the fuse in the
plug top! The possibility of that is zero under normal circumstances,

Yes, agreed.

so it would be reasonable to assume that either the plug
top fuse had blown or the amp had an internal fault.

Correct

In either case the amp, which runs unattended in
the loft, has to be scrapped.

Utter drivel

It would be too risky to just change the fuse.

On what basis do you come to that conclusion?

I'd guess he'd come to that conclusion on the basis of many years of
practical experience of just such equipment in exactly the situation
described. We all know fuses *can* simply fail with age, but the price
of a small RF amplifier is trivial compared with the price of a house
or the lives of its inhabitants, so it isn't worth the risk.

Rod.

"Mike" wrote in message
...
On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:

If I went into a loft and found a domestic distribution amplifier that was
dead I would test for a mains supply and if there was one I would scrap
the
amp. I would bother checking whether someone had removed the fuse in the
plug top! The possibility of that is zero under normal circumstances,

Yes, agreed.

so it would be reasonable to assume that either the plug
top fuse had blown or the amp had an internal fault.

Correct

In either case the amp, which runs unattended in
the loft, has to be scrapped.

Utter drivel

It would be too risky to just change the fuse.

On what basis do you come to that conclusion?

It would, in fact, be a seriously bad thing to do.

Why?

So that part of the programme was ********.

And your post isn't?


Since they had the CAI on board I would have thought
they could have cooked up a better 'fault'. How about making it look as if
someone had put a heavy case in the loft and it had pulled the downlead
out
of the amplifier's aerial socket? This is a common situation. Idiots!

Pity, I had thought more hightly of you and was considering putting
some work your way. On the basis of your posting I reckon you'd be
selling me oxygen free copper directional coax for a line of sight 10
miles from Emley aerial.

P.S. Are you sure you weren't ****ed out of your skull when you
posted?


Mike I am typing this slowly in case I get too technical for you.

You concede that either the plug-top fuse had blown or the amp
had an internal fault.

I assume that in this situation we are not going to attempt a
repair on the latter.

What's the likely current drawn from the mains by a typical domestic
aerial amp? Lets say for the sake of argument 100mA, in practice
it will be well under that figure.

What is the lowest value plug top fuse that is readily obtainable?
Answer 3000mA that's well over half a kilowatt. If available
continuously that's more than enough to start a fire.

Trust me, a 3A fuse will not blow with only a 100mA load, particularly
in this situation where it is on continuously.

Do we still want to try another fuse? FFS, remember where we are,
Do we want to risk tripping an RCD or MCB?


I used to see a lot of this stuff. What happens is the primary
winding of the miniature power transformer gets shorted turns
and gets very hot. Even in this condition the amplifier can
continue to work, until the fuse blows. I would expect the
internal protection to kick in first of course, the plug
fuse blowing suggests catastrophic failure.
--

Graham.
%Profound_observation%

"Graham" wrote in message
...

"Mike" wrote in message
...
On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:

If I went into a loft and found a domestic distribution amplifier that
was
dead I would test for a mains supply and if there was one I would scrap
the
amp. I would bother checking whether someone had removed the fuse in the
plug top! The possibility of that is zero under normal circumstances,

Yes, agreed.

so it would be reasonable to assume that either the plug
top fuse had blown or the amp had an internal fault.

Correct

In either case the amp, which runs unattended in
the loft, has to be scrapped.

Utter drivel

It would be too risky to just change the fuse.

On what basis do you come to that conclusion?

It would, in fact, be a seriously bad thing to do.

Why?

So that part of the programme was ********.

And your post isn't?


Since they had the CAI on board I would have thought
they could have cooked up a better 'fault'. How about making it look as
if
someone had put a heavy case in the loft and it had pulled the downlead
out
of the amplifier's aerial socket? This is a common situation. Idiots!

Pity, I had thought more hightly of you and was considering putting
some work your way. On the basis of your posting I reckon you'd be
selling me oxygen free copper directional coax for a line of sight 10
miles from Emley aerial.

P.S. Are you sure you weren't ****ed out of your skull when you
posted?


Mike I am typing this slowly in case I get too technical for you.

You concede that either the plug-top fuse had blown or the amp
had an internal fault.

I assume that in this situation we are not going to attempt a
repair on the latter.

What's the likely current drawn from the mains by a typical domestic
aerial amp? Lets say for the sake of argument 100mA, in practice
it will be well under that figure.

What is the lowest value plug top fuse that is readily obtainable?
Answer 3000mA that's well over half a kilowatt. If available
continuously that's more than enough to start a fire.

Trust me, a 3A fuse will not blow with only a 100mA load, particularly
in this situation where it is on continuously.

Do we still want to try another fuse? FFS, remember where we are,
Do we want to risk tripping an RCD or MCB?


I used to see a lot of this stuff. What happens is the primary
winding of the miniature power transformer gets shorted turns
and gets very hot. Even in this condition the amplifier can
continue to work, until the fuse blows. I would expect the
internal protection to kick in first of course, the plug
fuse blowing suggests catastrophic failure.
--


At one time there were one amp plug fuses (few and far between admittedly)
available which I used to order and fit for stuff like aerial amplifiers
wherever possible.

However I totally agree that it's best to err on the side of caution, even
if a one amp fuse blows, three or four years ago I did actually send Bill a
couple of photos of one of those white German amplifiers in rather a bad
way, which I found in a loft.

I've also come across a number of setback labgear masthead power supplies
which judging by the brown burn marks on the case have got a bit too hot for
comfort.

I even found one (screwed to a skirting board) which was totally wrecked
internally, so it appears that even good quality manufacturers aren't
totally immune from this particular problem.



Graham.
%Profound_observation%

At one time there were one amp plug fuses (few and far between admittedly)
available which I used to order and fit for stuff like aerial amplifiers
wherever possible.

However I totally agree that it's best to err on the side of caution, even
if a one amp fuse blows, three or four years ago I did actually send Bill
a couple of photos of one of those white German amplifiers in rather a bad
way, which I found in a loft.

I've also come across a number of setback labgear masthead power supplies
which judging by the brown burn marks on the case have got a bit too hot
for comfort.

I even found one (screwed to a skirting board) which was totally wrecked
internally, so it appears that even good quality manufacturers aren't
totally immune from this particular problem.


On the subject of plug fuses,
Most of the equipment I install is powered by an IEC
13A plug (kettle lead)
Sometimes during an installation they get mixed up
And in some cases I have to replace them with
cables that have an Electrak plug (also fused)
http://www.electrak.co.uk/products_accessories.php

I recently did a fuse inventory
Most of the kit like Dell computers and monitors and
various printers were supplied with 5A fused plugs
The Brother laser printers came with 13A fuses.
Quick-heat fuser so not surprising.

The big surprise for me was the Cisco 1801 router
which sports an IEC lead with a 10A fuse.

--

Graham.
%Profound_observation%

In message , Graham
writes

At one time there were one amp plug fuses (few and far between admittedly)
available which I used to order and fit for stuff like aerial amplifiers
wherever possible.

However I totally agree that it's best to err on the side of caution, even
if a one amp fuse blows, three or four years ago I did actually send Bill
a couple of photos of one of those white German amplifiers in rather a bad
way, which I found in a loft.

I've also come across a number of setback labgear masthead power supplies
which judging by the brown burn marks on the case have got a bit too hot
for comfort.

I even found one (screwed to a skirting board) which was totally wrecked
internally, so it appears that even good quality manufacturers aren't
totally immune from this particular problem.


On the subject of plug fuses,
Most of the equipment I install is powered by an IEC
13A plug (kettle lead)
No it isn't, a kettle lead is a "Hot Condition" socket, and has a cutout
in it. The leads you mean won't fit into a kettle.

--
Kevin Seal
F800ST
{kevin at the hyphen seal hyphen house dot freeserve dot co dot uk}

Mike wrote:
On Tue, 29 May 2007 20:54:07 +0100, "Bill Wright"
wrote:


If I went into a loft and found a domestic distribution amplifier that was
dead I would test for a mains supply and if there was one I would scrap the
amp. I would bother checking whether someone had removed the fuse in the
plug top! The possibility of that is zero under normal circumstances,


Yes, agreed.


so it would be reasonable to assume that either the plug
top fuse had blown or the amp had an internal fault.


Correct


In either case the amp, which runs unattended in
the loft, has to be scrapped.


Utter drivel


It would be too risky to just change the fuse.


On what basis do you come to that conclusion?


It would, in fact, be a seriously bad thing to do.


Why?


So that part of the programme was ********.


And your post isn't?



Since they had the CAI on board I would have thought
they could have cooked up a better 'fault'. How about making it look as if
someone had put a heavy case in the loft and it had pulled the downlead out
of the amplifier's aerial socket? This is a common situation. Idiots!


Pity, I had thought more hightly of you and was considering putting
some work your way. On the basis of your posting I reckon you'd be
selling me oxygen free copper directional coax for a line of sight 10
miles from Emley aerial.

P.S. Are you sure you weren't ****ed out of your skull when you
posted?


Unexplained fuse failure is always a cause for concern and should be
investigated. However the low cost of a loft amp does not justify much
investigation other than checking for rodent damage to the mains lead or
other obvious physical damage. For an item that is out of sight in the
loft replacment is a better option especially if the amplifier is
getting old.
Dave

In article ,
Graham wrote:
What's the likely current drawn from the mains by a typical domestic
aerial amp? Lets say for the sake of argument 100mA, in practice
it will be well under that figure.

What is the lowest value plug top fuse that is readily obtainable?
Answer 3000mA that's well over half a kilowatt. If available
continuously that's more than enough to start a fire.

The fuse in a plug is there purely to protect the flex and the smallest
flex used is capable of blowing a 3 amp fuse. If the equipment itself
needs extra protection it will either have its own lower rated fuse or
more likely a thermal one in the transformer windings.

--
*I want it all and I want it delivered

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