More fun with plugpacks and audio gear

Continued struggles with plugpacks and their high frequency common
mode feedthrough. Was powering a couple of home made musical devices
using them, have only just sorted out the mess. One is a MIDI
controller, the other an onstage click light generator which runs
under serial RS232 command from the controller. The rest of the gear
(all commercial) is floating on the mixer desk to avoid earth loops,
all that works fine, but I had to ground the MIDI controller case to
prevent tickles from the plugpack supply. That stuffed up the click
generator, because the HF feedthrough on its power supply was
propagating back along the data cable and intermittently corrupting
the data. Now all the digital devices run from a single, conventional
mains tranny/rectifier/regulator supply with a solid mains ground, and
everything is hunky dory. There are no ground loops because the MIDI
connections are galvanically isolated, thank christ.

So the humble plugpack has characteristics that need to be watched
sometimes. It's not just a convenient mains-powered battery. I have
new respect for the cautions that come with musical gear regarding not
substituting brand X powerpacks.

 

[Phil Allison]

nor...@googlegroups.com wrote:

Continued struggles with plugpacks and their high frequency common
mode feedthrough. Was powering a couple of home made musical devices
using them, have only just sorted out the mess. One is a MIDI
controller, the other an onstage click light generator which runs
under serial RS232 command from the controller. The rest of the gear
(all commercial) is floating on the mixer desk to avoid earth loops,
all that works fine, but I had to ground the MIDI controller case to
prevent tickles from the plugpack supply. That stuffed up the click
generator, because the HF feedthrough on its power supply was
propagating back along the data cable and intermittently corrupting
the data. Now all the digital devices run from a single, conventional
mains tranny/rectifier/regulator supply with a solid mains ground, and
everything is hunky dory. There are no ground loops because the MIDI
connections are galvanically isolated, thank christ.

So the humble plugpack has characteristics that need to be watched
sometimes. It's not just a convenient mains-powered battery. I have
new respect for the cautions that come with musical gear regarding not
substituting brand X powerpacks.

** I just ran some bench tests on a SMPS plugpak that was in my workshop - under a light load.

Firstly, just with a DMM from the DC plug to ground = 104VAC.

Then with a 50MHz BWD scope probe from DC plug to ground with a 2700ohm resistor in parallel = 6mS bursts of high frequency, repeated at 100Hz, with a peak amplitude of 1.2V.

Then with a DSO using the FFT function (Rigol DS1052e) = switching harmonics at all multiples of 63kHz up to 630kHz, the first three being around 300mV rms.

Conclusion:

there sure ain't any ES shielding between the primary and secondary of the switching tranny inside it and EMC regulations do not require it.



..... Phil

 

[Phil Allison]

nor...@googlegroups.com wrote:

Just did a quick test on a powerpack that comes with a musical device
(Alessis model S090085A34), supplied with a drum machine. In the
manual there's a stern warning on page 1 not to substitute other makes
of supply.

The open circuit common mode voltage was about 8 volts, an OOM lower
than any of the ordinary packs I've checked. So it looks like some
attempt's been made to control feedthru. However, like most of these
devices, the mains plug is only 2-pin, so there can't be a grounded
interwinding screen.

** An inter-winding screen can be linked to the supply neutral pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first place is to use an AC plug pak - guaranteed to contain an iron transformer.

Alesis have done this in the past and derived multiple DC rails by doubling.



..... Phil

 

[Phil Allison]

, Trevor Wilson wrote:
Phil Allison wrote:

** An inter-winding screen can be linked to the supply neutral pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first place is to use an AC plug pak - guaranteed to contain an iron transformer.

Alesis have done this in the past and derived multiple DC rails by doubling.


**AC plugpacks are getting quite rare.

** 9 types are listed in the WES catalogue.

Any manufacturer would normally source them direct from China and get any set of ratings they specify.

PLUS, AC external adaptors do NOT have to met stupid MEPS regualations.

I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/- 12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any more.


..... Phil

 

On Sat, 27 Dec 2014 18:14:36 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

nor...@googlegroups.com wrote:

Continued struggles with plugpacks and their high frequency common
mode feedthrough. Was powering a couple of home made musical devices
using them, have only just sorted out the mess. One is a MIDI
controller, the other an onstage click light generator which runs
under serial RS232 command from the controller. The rest of the gear
(all commercial) is floating on the mixer desk to avoid earth loops,
all that works fine, but I had to ground the MIDI controller case to
prevent tickles from the plugpack supply. That stuffed up the click
generator, because the HF feedthrough on its power supply was
propagating back along the data cable and intermittently corrupting
the data. Now all the digital devices run from a single, conventional
mains tranny/rectifier/regulator supply with a solid mains ground, and
everything is hunky dory. There are no ground loops because the MIDI
connections are galvanically isolated, thank christ.

So the humble plugpack has characteristics that need to be watched
sometimes. It's not just a convenient mains-powered battery. I have
new respect for the cautions that come with musical gear regarding not
substituting brand X powerpacks.


** I just ran some bench tests on a SMPS plugpak that was in my workshop - under a light load.

Firstly, just with a DMM from the DC plug to ground = 104VAC.

Then with a 50MHz BWD scope probe from DC plug to ground with a 2700ohm resistor in parallel = 6mS bursts of high frequency, repeated at 100Hz, with a peak amplitude of 1.2V.

Then with a DSO using the FFT function (Rigol DS1052e) = switching harmonics at all multiples of 63kHz up to 630kHz, the first three being around 300mV rms.

Conclusion:

there sure ain't any ES shielding between the primary and secondary of the switching tranny inside it and EMC regulations do not require it.



.... Phil

Just did a quick test on a powerpack that comes with a musical device
(Alessis model S090085A34), supplied with a drum machine. In the
manual there's a stern warning on page 1 not to substitute other makes
of supply.

The open circuit common mode voltage was about 8 volts, an OOM lower
than any of the ordinary packs I've checked. So it looks like some
attempt's been made to control feedthru. However, like most of these
devices, the mains plug is only 2-pin, so there can't be a grounded
interwinding screen.

 

[Trevor Wilson]

On 29/12/2014 3:15 PM, Phil Allison wrote:

nor...@googlegroups.com wrote:


Just did a quick test on a powerpack that comes with a musical device
(Alessis model S090085A34), supplied with a drum machine. In the
manual there's a stern warning on page 1 not to substitute other makes
of supply.

The open circuit common mode voltage was about 8 volts, an OOM lower
than any of the ordinary packs I've checked. So it looks like some
attempt's been made to control feedthru. However, like most of these
devices, the mains plug is only 2-pin, so there can't be a grounded
interwinding screen.


** An inter-winding screen can be linked to the supply neutral pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first place is to use an AC plug pak - guaranteed to contain an iron transformer.

Alesis have done this in the past and derived multiple DC rails by doubling.

**AC plugpacks are getting quite rare. I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock. Around 600, if anyone is interested
in acquiring some. I purchased them for a project, after the roughly 8%
failure rate of the Chinese ones purchased. The Telectran ones have
shown to be way less than 1% failure rate. And that is almost 20 years
on. Sadly, the client went belly-up, leaving me with 600 of the suckers.


--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[Trevor Wilson]

On 29/12/2014 5:43 PM, Phil Allison wrote:

, Trevor Wilson wrote:
Phil Allison wrote:



** An inter-winding screen can be linked to the supply neutral pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first place is to use an AC plug pak - guaranteed to contain an iron transformer.

Alesis have done this in the past and derived multiple DC rails by doubling.


**AC plugpacks are getting quite rare.


** 9 types are listed in the WES catalogue.

Any manufacturer would normally source them direct from China and get any set of ratings they specify.

PLUS, AC external adaptors do NOT have to met stupid MEPS regualations.


I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/- 12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any more.


.... Phil

**Let's see if we can get 600 people to build one each. I'll sell them
one of my transformers for a piddling 7 Bucks. My original cost price
was $14.00. They're fitted with a 1.5 Metre mains lead and a 1.5 Metre
secondary lead, terminated in one of those standard power supply plugs
(in the old days they were referred to as a National Power Supply Plug,
because, I think, Panasonic pioneered the plug).

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[keithr]

On 29/12/2014 6:11 PM, Trevor Wilson wrote:

On 29/12/2014 5:43 PM, Phil Allison wrote:
, Trevor Wilson wrote:
Phil Allison wrote:



** An inter-winding screen can be linked to the supply neutral
pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first
place is to use an AC plug pak - guaranteed to contain an iron
transformer.

Alesis have done this in the past and derived multiple DC rails by
doubling.


**AC plugpacks are getting quite rare.


** 9 types are listed in the WES catalogue.

Any manufacturer would normally source them direct from China and get
any set of ratings they specify.

PLUS, AC external adaptors do NOT have to met stupid MEPS regualations.


I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published
in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/-
12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any more.


.... Phil


**Let's see if we can get 600 people to build one each. I'll sell them
one of my transformers for a piddling 7 Bucks. My original cost price
was $14.00. They're fitted with a 1.5 Metre mains lead and a 1.5 Metre
secondary lead, terminated in one of those standard power supply plugs
(in the old days they were referred to as a National Power Supply Plug,
because, I think, Panasonic pioneered the plug).

Jaycar sell them, the price is significantly more than 7 bucks but then
they give a lot more than 100mA.

 

[Phil Allison]

Trevor Wilson wrote:

**Let's see if we can get 600 people to build one each.

** Ha ha, not bloody likely.

I'll sell them one of my transformers for a piddling 7 Bucks.
My original cost price was $14.00. They're fitted with a 1.5
Metre mains lead and a 1.5 Metre secondary lead,

** Err so not "plugpaks" at all - but simply a boxed tranny with attached leads.


.... Phil

 

[Computer Nerd Kev]

keithr <user@domain.invalid> wrote:

I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published
in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/-
12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any more.


.... Phil


**Let's see if we can get 600 people to build one each. I'll sell them
one of my transformers for a piddling 7 Bucks. My original cost price
was $14.00. They're fitted with a 1.5 Metre mains lead and a 1.5 Metre
secondary lead, terminated in one of those standard power supply plugs
(in the old days they were referred to as a National Power Supply Plug,
because, I think, Panasonic pioneered the plug).

Jaycar sell them, the price is significantly more than 7 bucks but then
they give a lot more than 100mA.

Rockby Electronics in Melbourne have 16VAC 1.5A for $12.00:
http://www.rockby.com.au/catresultsSql_12.cfm?Stock_no=41724

Also some crazy cheap DC plugpacks which look certain to be transformer
ones too:
18V 250mA (PK-4) for $5:
http://www.rockby.com.au/catresultssQL_12.cfm?Stock_no=41798

15V 500mA (PK-2) for $5:
http://www.rockby.com.au/catresultssQL_12.cfm?Stock_no=41799
Under "Unregulated" on this page, indicating they're transformer:
http://www.nucleuscomputer.com.au/nucproducts/Comparts/Powersupplies/
Power%20Supplies%20DC%20Low%20Voltage/Power%20Supplies%20DC%20Low
%20Voltage_Other.htm

They'll be surplus stock from somewhere, so whether they're a good
brand or not will be pretty random.

--
__ __
#_ < |\| |< _#

 

[Trevor Wilson]

On 29/12/2014 9:28 PM, keithr wrote:

On 29/12/2014 6:11 PM, Trevor Wilson wrote:
On 29/12/2014 5:43 PM, Phil Allison wrote:
, Trevor Wilson wrote:
Phil Allison wrote:



** An inter-winding screen can be linked to the supply neutral
pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first
place is to use an AC plug pak - guaranteed to contain an iron
transformer.

Alesis have done this in the past and derived multiple DC rails by
doubling.


**AC plugpacks are getting quite rare.


** 9 types are listed in the WES catalogue.

Any manufacturer would normally source them direct from China and get
any set of ratings they specify.

PLUS, AC external adaptors do NOT have to met stupid MEPS regualations.


I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published
in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/-
12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any more.


.... Phil


**Let's see if we can get 600 people to build one each. I'll sell them
one of my transformers for a piddling 7 Bucks. My original cost price
was $14.00. They're fitted with a 1.5 Metre mains lead and a 1.5 Metre
secondary lead, terminated in one of those standard power supply plugs
(in the old days they were referred to as a National Power Supply Plug,
because, I think, Panasonic pioneered the plug).

Jaycar sell them, the price is significantly more than 7 bucks but then
they give a lot more than 100mA.

**Provided you don't mind the appalling quality associated with Jaycar
products, then that may well be a good choice. Due to an incredibly high
failure rate of Jaycar products, they are my supplier of last resort. At
present, my choice is (in approximate order):

Element14
RS Components
X-On (on recently began dealing with them - they seem pretty good, so far)
Altronics
WES

(daylight)

Jaycar

Naturally, there is a bunch of overseas suppliers dotted amongst that list.

In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[Grant]

On Tue, 30 Dec 2014 07:43:18 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

....

In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

How much for a couple posted to Bendigo? My header addr is valid, Thanks,

Grant.

 

[Trevor Wilson]

On 30/12/2014 9:34 AM, Grant wrote:

On Tue, 30 Dec 2014 07:43:18 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

...
In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

How much for a couple posted to Bendigo? My header addr is valid, Thanks,

Grant.

**5 Bucks each + whatever Australia Post gouges these days. I'll suss
out a suitable package and postage cost later today.

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[Trevor Wilson]

On 30/12/2014 10:19 AM, Phil Allison wrote:

Trevor Wilson wrote:


**Let's see if we can get 600 people to build one each.


** Ha ha, not bloody likely.

**Yeah, I figured as much.

I'll sell them one of my transformers for a piddling 7 Bucks.
My original cost price was $14.00. They're fitted with a 1.5
Metre mains lead and a 1.5 Metre secondary lead,


** Err so not "plugpaks" at all - but simply a boxed tranny with attached leads.

**Correct. More expensive to make. They work well as a replacement
transformer for (1980s ~ 1990s) Thorens turntables. Significantly less
expensive than the $150.00+ that Thorens want for the same product.

Very handy things. Every tech and electronics enthusiast should have a
half dozen in their junk box.



--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[keithr]

On 30/12/2014 6:43 AM, Trevor Wilson wrote:

On 29/12/2014 9:28 PM, keithr wrote:
On 29/12/2014 6:11 PM, Trevor Wilson wrote:
On 29/12/2014 5:43 PM, Phil Allison wrote:
, Trevor Wilson wrote:
Phil Allison wrote:



** An inter-winding screen can be linked to the supply neutral
pin to supress
capacitive feed-through of 50Hz and switching frequency voltages.

But the easiest way for maker to avoid the problem in the first
place is to use an AC plug pak - guaranteed to contain an iron
transformer.

Alesis have done this in the past and derived multiple DC rails by
doubling.


**AC plugpacks are getting quite rare.


** 9 types are listed in the WES catalogue.

Any manufacturer would normally source them direct from China and get
any set of ratings they specify.

PLUS, AC external adaptors do NOT have to met stupid MEPS
regualations.


I have a bunch of 16VAC, 100mA,
AUSTRALIAN made, Telectran in stock.

** Perfect for my old "Low Distortion Oscillator" project - published
in EA magazine in February and March of 1989.

Two diodes, two electros plus resistors and zeners gave regulated, +/-
12VDC rails for the NE5532 and NE5534 op-amps.

DSE did a kit for it, but I doubt the PCB is readily available any
more.


.... Phil


**Let's see if we can get 600 people to build one each. I'll sell them
one of my transformers for a piddling 7 Bucks. My original cost price
was $14.00. They're fitted with a 1.5 Metre mains lead and a 1.5 Metre
secondary lead, terminated in one of those standard power supply plugs
(in the old days they were referred to as a National Power Supply Plug,
because, I think, Panasonic pioneered the plug).

Jaycar sell them, the price is significantly more than 7 bucks but then
they give a lot more than 100mA.

**Provided you don't mind the appalling quality associated with Jaycar
products, then that may well be a good choice. Due to an incredibly high
failure rate of Jaycar products, they are my supplier of last resort. At
present, my choice is (in approximate order):

Element14
RS Components
X-On (on recently began dealing with them - they seem pretty good, so far)
Altronics
WES

(daylight)

Jaycar

Naturally, there is a bunch of overseas suppliers dotted amongst that list.

In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

I only bought on for Xmas tree lights.

 

[Trevor Wilson]

On 30/12/2014 9:34 AM, Grant wrote:

On Tue, 30 Dec 2014 07:43:18 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

...
In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

How much for a couple posted to Bendigo? My header addr is valid, Thanks,

Grant.

**Damned Australia Post. Their prices are now through the roof. Two PSUs
weigh in at 725g. Too much for a 500g prepaid satchel. Have to select
the 3kg satchel at $13.40. I sussed out a package of 10cm cube, weighing
1kg and the 3kg satchel was still cheaper.

Bummer.



--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

 

[Grant]

On Wed, 31 Dec 2014 16:53:02 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

On 30/12/2014 9:34 AM, Grant wrote:
On Tue, 30 Dec 2014 07:43:18 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

...
In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

How much for a couple posted to Bendigo? My header addr is valid, Thanks,

Grant.


**Damned Australia Post. Their prices are now through the roof. Two PSUs
weigh in at 725g. Too much for a 500g prepaid satchel. Have to select
the 3kg satchel at $13.40. I sussed out a package of 10cm cube, weighing
1kg and the 3kg satchel was still cheaper.

No worries, I didn't have a home for them, yet. I don't have friends who
do electronics, so cannot make a bigger order.

If they were in China, they'd probably get free postage

Grant.

 

[Trevor Wilson]

On 1/01/2015 3:46 AM, Grant wrote:

On Wed, 31 Dec 2014 16:53:02 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

On 30/12/2014 9:34 AM, Grant wrote:
On Tue, 30 Dec 2014 07:43:18 +1100, Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

...
In all fairness, the transformers I have are the absolute best quality
available (made in Australia, not China). They are certified for use in
medical situations. They are epoxy encapsulated and, for all intents, do
not fail. I would certainly entertain offers for quantity sales.
Frankly, they are taking up space and I need to get rid of them. 2 Bucks
each in 100 off would be a reasonable price I should think.

How much for a couple posted to Bendigo? My header addr is valid, Thanks,

Grant.


**Damned Australia Post. Their prices are now through the roof. Two PSUs
weigh in at 725g. Too much for a 500g prepaid satchel. Have to select
the 3kg satchel at $13.40. I sussed out a package of 10cm cube, weighing
1kg and the 3kg satchel was still cheaper.

No worries, I didn't have a home for them, yet. I don't have friends who
do electronics, so cannot make a bigger order.

If they were in China, they'd probably get free postage

Grant.

**If you speak to anyone from Australia Post, they'll explain that this
free post from China is killing them. Postage costs in and from China
are dirt cheap. Trouble is, due to international arrangements, Australia
Post covers the costs within Australia. Since there is a Hell of a lot
more traffic coming from China, rather than the other way 'round, our
internal system suffers. Maybe we all need to start posting house-bricks
to China?

--
Trevor Wilson
www.rageaudio.com.au

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com