[Trailboss]

I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the DUT.
(usually tube amp). some older live chassis stuff too.

My question is how to deal with my other mains powered test equipment, these
include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should just
the scope sit on an Isolation transformer?

Should the device under test chassis ground bypass the variac and go
directly to the mains outlet?

All this equipment will be connected to the same ckt on the service panel
providing a single point of ground.

The service panel has been overhauled, neutral/ground bus renewed and a new
earth rod installed down into the water table, (I live on a barrier beach
and hit water at about six feet).

any help appreciated,

JVC

[NT]

On Sep 20, 6:50*pm, "Trailboss" wrote:
I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the DUT..
(usually tube amp). some older live chassis stuff too.

My question is how to deal with my other mains powered test equipment, these
include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should just
the scope sit on an Isolation transformer?

Should the device under test chassis ground bypass the variac and go
directly to the mains outlet?

All this equipment will be connected to the same ckt on the service panel
providing a single point of ground.

The service panel has been overhauled, neutral/ground bus renewed and a new
earth rod installed down into the water table, (I live on a barrier beach
and hit water at about six feet).

any help appreciated,

JVC

Makes a lot more sense to run the DUT off the iso imho. If/when you
need the scope unearthed, an RCD can deal with the resulting risk,
albeit imperfectly. A 2nd iso-tf is better. A pocket scope is another
option. A final option is an opamp based voltage difference level
shifter. With a hi z input chain, measuring mains is relatively easy,
and A-B is trivial with an opamp.


NT

[Phil Allison[_3_]]

"Trailboss"

I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the DUT.
(usually tube amp). some older live chassis stuff too.

** Live chassis tube amps or something else like TV sets ?


My question is how to deal with my other mains powered test equipment,
these include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should just
the scope sit on an Isolation transformer?

** Never earth isolate ( ie float) your scope, that is very dangerous.

No need exists for an isolation tranny, with the exception of servicing
modern SMPSs and a few TV sets.


Should the device under test chassis ground bypass the variac and go
directly to the mains outlet?

** Huh ?

The variac should have a 3 pin outlet fitted with mains ground.




.... Phil

[NT]

On Sep 21, 1:56*am, "Phil Allison" wrote:
"Trailboss"



I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the DUT.
(usually tube amp). some older live chassis stuff too.

** Live chassis tube amps or something else like TV sets ?

My question is how to deal with my other mains powered test equipment,
these include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should just
the scope sit on an Isolation transformer?

** Never earth isolate ( ie float) your scope, that is very dangerous.

Hardly. Deaths per annum from electrocution: typ 21 a year in UK.
Deaths per annum from unearthed scopes: about zero. You have something
to back up your claim?


No need exists for an isolation tranny, with the exception of servicing
modern SMPSs and a few TV sets.

Servicing live chassis radios with no iso is far riskier than using an
unearthed scope with no iso or rcd.


Should the device under test chassis ground bypass the variac and go
directly to the mains outlet?

** Huh ?

The variac should have a 3 pin outlet fitted with mains ground.

... *Phil

[Phil Allison[_3_]]

"Nutcase Turd."
, "Phil Allison" :
"Trailboss"

I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the
DUT.
(usually tube amp). some older live chassis stuff too.

** Live chassis tube amps or something else like TV sets ?

My question is how to deal with my other mains powered test equipment,
these include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should
just
the scope sit on an Isolation transformer?

** Never earth isolate ( ie float) your scope, that is very dangerous.

Hardly.

** It is - you ****ing nut case.


No need exists for an isolation tranny, with the exception of servicing
modern SMPSs and a few TV sets.

Servicing live chassis radios


** Same risks as live chassis TV sets.

**** off you retarded jerk.



.... Phil

[NT]

On Sep 21, 8:25*am, "Phil Allison" wrote:
"Nutcase Turd."
, "Phil Allison" :



"Trailboss"
I am setting up my test bench.

I have a variac with an iron vane ammeter and volt meter to serve the
DUT.
(usually tube amp). some older live chassis stuff too.

** Live chassis tube amps or something else like TV sets ?

My question is how to deal with my other mains powered test equipment,
these include:

HP sine generator
Distortion analyzer
VTVM
Old tube Tek scopes
Newer Philips scope

If these units are all converted to three wire polarized plugs should
just
the scope sit on an Isolation transformer?

** Never earth isolate ( ie float) your scope, that is very dangerous.

Hardly.

** It is - *you ****ing nut case.

No need exists for an isolation tranny, with the exception of servicing
modern SMPSs and a few TV sets.

Servicing live chassis radios

** Same risks as live chassis TV sets.

* * **** off you retarded jerk.

... *Phil

I ddint think you could back up your bs

[Phil Allison[_3_]]

"Nutcase Troll"



** **** off, you retarded ****ing jerk.



.... Phil

[John L Stewart]

For off ground measurements I use a Picoscope TA041 Differential Probe in front of the scope. OK to 700 volts common mode.

http://accessories.picotech.com/acti...bes.html#TA041

These daze my scoping is done with one of the other of Pico Scopes PC Scopes-

http://www.picotech.com/oscilloscope.html

That way results can be transferred direct to the PC for later use. The 2-channel, 100 MHz analogue scope sits on the shelf gathering dust.

Gotta get on the bike now.

Cheers, John

[glenbadd]

ARTA, Visual Analyser

[HpW]

Patrick,

I have sitting around here with an analyser program and sound card.

Well, the big question will be in what dynamics you like the measure...

The HW brand (soundcard) has some band limited spec's (usuall for tube stuff
good enough)
and good things are not free.. as you may not like to work for free O

Cheers

hp

http://www.hpw-works.com