hi


was trying to find a power supply i could use with my ham gear , thats
around 13v dc and 30-50 amps and must be analog/linear type

i need to be near it, and the usual transformer buzzing is annoying

so i was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as i thought those
would be quieter

any know of any manufactures of something like this??


thanks

"ml" wrote in message
...
Hi !

I was trying to find a power supply I could use with my ham gear, that's
around 13 VDC and 30-50 Amps and must be analog/linear type

I need to be near it, and the usual transformer buzzing is annoying

so I was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as I thought those
would be quieter.

Are there any manufactures of something like this??

Thanks.

You have to build it yourself, but the transformer is easy to acquire.

Plitron Manufacturing Inc was established in 1983 and specializes in the
design, development and manufacturing of toroidal transformers.
PLITRON toroidal transformers are widely specified and preferred for
demanding applications in audio, medical, broadcast, telecommunications,
computer, power conditioning, and other industrial sectors.
http://www.plitron.com/

PLITRON MANUFACTURING INC
8-601 Magnetic Drive,
Toronto, Ontario
M3J 3J2
Canada
Tel 416-667-9914
Fax 416-667-8928

Hammond Manufacturing also makes toroidal trasnformers
http://www.hammondmfg.com/5cpwr.htm

http://www.hammondmfg.com/hist.htm
Since its modest beginnings in the basement of the family homestead 91 years
ago, Hammond has grown into two separate, medium-sized companies with
combined annual sales of over $200 Million & over 1,200 employees located in
12 facilities around North America, the UK and Australia.

In article ,
"gb" wrote:

"ml" wrote in message
...
Hi !

I was trying to find a power supply I could use with my ham gear, that's
around 13 VDC and 30-50 Amps and must be analog/linear type

I need to be near it, and the usual transformer buzzing is annoying

so I was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as I thought those
would be quieter.

Are there any manufactures of something like this??

Thanks.

You have to build it yourself, but the transformer is easy to acquire.

Plitron Manufacturing Inc was established in 1983 and specializes in the
design, development and manufacturing of toroidal transformers.
PLITRON toroidal transformers are widely specified and preferred for
demanding applications in audio, medical, broadcast, telecommunications,
computer, power conditioning, and other industrial sectors.
http://www.plitron.com/

PLITRON MANUFACTURING INC
8-601 Magnetic Drive,
Toronto, Ontario
M3J 3J2
Canada
Tel 416-667-9914
Fax 416-667-8928

Hammond Manufacturing also makes toroidal trasnformers
http://www.hammondmfg.com/5cpwr.htm

http://www.hammondmfg.com/hist.htm
Since its modest beginnings in the basement of the family homestead 91 years
ago, Hammond has grown into two separate, medium-sized companies with
combined annual sales of over $200 Million & over 1,200 employees located in
12 facilities around North America, the UK and Australia.

hi

thanks very much for responding

interesting links, but hopfully i won't 'have to' build one i can't
believe some company out there dosn't make either a sealed"" quite
xformer or torriod or something thats linear but not noisly
db wise or rf wise then aagain maybe i an mistaken I supposed i
could take my astron remove the transformer and put in a sutible
torioed not sure if it would be possible to do a 'direct' replacement
but perhaps if i could identify the proper type of torid and
presuming it's able to 'fit'


but its a fun experiment

"ml" wrote in message
...
In article ,
"gb" wrote:

"ml" wrote in message
...
Hi !

I was trying to find a power supply I could use with my ham gear,
that's
around 13 VDC and 30-50 Amps and must be analog/linear type

I need to be near it, and the usual transformer buzzing is annoying

so I was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as I thought those
would be quieter.

Are there any manufactures of something like this??

Thanks.

You have to build it yourself, but the transformer is easy to acquire.

Plitron Manufacturing Inc was established in 1983 and specializes in the
design, development and manufacturing of toroidal transformers.
PLITRON toroidal transformers are widely specified and preferred for
demanding applications in audio, medical, broadcast, telecommunications,
computer, power conditioning, and other industrial sectors.
http://www.plitron.com/

PLITRON MANUFACTURING INC
8-601 Magnetic Drive,
Toronto, Ontario
M3J 3J2
Canada
Tel 416-667-9914
Fax 416-667-8928

Hammond Manufacturing also makes toroidal trasnformers
http://www.hammondmfg.com/5cpwr.htm

http://www.hammondmfg.com/hist.htm
Since its modest beginnings in the basement of the family homestead 91
years
ago, Hammond has grown into two separate, medium-sized companies with
combined annual sales of over $200 Million & over 1,200 employees located
in
12 facilities around North America, the UK and Australia.

hi

thanks very much for responding

interesting links, but hopfully i won't 'have to' build one i can't
believe some company out there dosn't make either a sealed"" quite
xformer or torriod or something thats linear but not noisly
db wise or rf wise then aagain maybe i an mistaken I supposed i
could take my astron remove the transformer and put in a sutible
torioed not sure if it would be possible to do a 'direct' replacement
but perhaps if i could identify the proper type of torid and
presuming it's able to 'fit'


but its a fun experiment

Why not just use a car battery with a much lower current 'trickle' charger
glued across it. Or, there are plenty of switchers around these days for
that sort of current, which are electrically quiet. I have a 25 amp
continuous switcher from G-Comm in my shack, and it is pretty 'radio quiet'
on all the bands I use.

Arfa

On Sun, 02 Mar 2008 22:43:13 GMT, ml wrote:

:hi
:
:
:was trying to find a power supply i could use with my ham gear , thats
:around 13v dc and 30-50 amps and must be analog/linear type
:
:i need to be near it, and the usual transformer buzzing is annoying
:
:so i was trying to google around for a supply that either has a
:sealed traansformer or perhaps uses a torriod as i thought those
:would be quieter
:
:any know of any manufactures of something like this??
:
:
:thanks


You might care to read some opinions on SMPS from radio amateurs
http://groups.google.com/group/rec.r...d2fd7cafa35162
(expand the full thread)

Join the group and ask them your questions etc.

On Sun, 02 Mar 2008 22:43:13 GMT, ml wrote:

:hi
:
:
:was trying to find a power supply i could use with my ham gear , thats
:around 13v dc and 30-50 amps and must be analog/linear type
:
:i need to be near it, and the usual transformer buzzing is annoying
:
:so i was trying to google around for a supply that either has a
:sealed traansformer or perhaps uses a torriod as i thought those
:would be quieter
:
:any know of any manufactures of something like this??
:
:
:thanks


Here's one link which might give some pointers to other info
http://www.andrewscom.com.au/site-section-09.htm

Then Google for the brand info in your region, eg. "SPS9600"

"ml" wrote in message
...
In article ,
"gb" wrote:

"ml" wrote in message
...
Hi !

I was trying to find a power supply I could use with my ham gear, that's
around 13 VDC and 30-50 Amps and must be analog/linear type

I need to be near it, and the usual transformer buzzing is annoying

so I was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as I thought those
would be quieter.

Are there any manufactures of something like this??

Thanks.

You have to build it yourself, but the transformer is easy to acquire.

Plitron Manufacturing Inc was established in 1983 and specializes in the
design, development and manufacturing of toroidal transformers.
PLITRON toroidal transformers are widely specified and preferred for
demanding applications in audio, medical, broadcast, telecommunications,
computer, power conditioning, and other industrial sectors.
http://www.plitron.com/

PLITRON MANUFACTURING INC
8-601 Magnetic Drive,
Toronto, Ontario
M3J 3J2
Canada
Tel 416-667-9914
Fax 416-667-8928

Hammond Manufacturing also makes toroidal trasnformers
http://www.hammondmfg.com/5cpwr.htm

http://www.hammondmfg.com/hist.htm
Since its modest beginnings in the basement of the family homestead 91 years
ago, Hammond has grown into two separate, medium-sized companies with
combined annual sales of over $200 Million & over 1,200 employees located in
12 facilities around North America, the UK and Australia.

hi

thanks very much for responding

interesting links, but hopfully i won't 'have to' build one i can't
believe some company out there dosn't make either a sealed"" quite
xformer or torriod or something thats linear but not noisly
db wise or rf wise then aagain maybe i an mistaken I supposed i
could take my astron remove the transformer and put in a sutible
torioed not sure if it would be possible to do a 'direct' replacement
but perhaps if i could identify the proper type of torid and
presuming it's able to 'fit'


but its a fun experiment


If it's audible buzz coming from the transformer, you might try tightening the
screws that bind the laminations. Sometimes the laminations become loose and
the magnetizing currents cause them to mechanically vibrate; thus the buzz.
Another thing to try would be to mechanically isolate the transformer by putting
rubber washers or bumpers between the transformer and the mounting surface on
the chassis of your power supply.

A toroid transformer would probably be quieter, but likely to be expensive.
Likely to be a custom order too, making it very expensive.

Cheers,

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

"In theory, there isn't any difference between theory and practice. In
practice, there is." - Yogi Berra

"ml" wrote in message
...
In article ,
"gb" wrote:

"ml" wrote in message
...
Hi !

I was trying to find a power supply I could use with my ham gear,
that's
around 13 VDC and 30-50 Amps and must be analog/linear type

I need to be near it, and the usual transformer buzzing is annoying

so I was trying to google around for a supply that either has a
sealed traansformer or perhaps uses a torriod as I thought those
would be quieter.

Are there any manufactures of something like this??

Thanks.

You have to build it yourself, but the transformer is easy to acquire.

Plitron Manufacturing Inc was established in 1983 and specializes in the
design, development and manufacturing of toroidal transformers.
PLITRON toroidal transformers are widely specified and preferred for
demanding applications in audio, medical, broadcast, telecommunications,
computer, power conditioning, and other industrial sectors.
http://www.plitron.com/

PLITRON MANUFACTURING INC
8-601 Magnetic Drive,
Toronto, Ontario
M3J 3J2
Canada
Tel 416-667-9914
Fax 416-667-8928

Hammond Manufacturing also makes toroidal trasnformers
http://www.hammondmfg.com/5cpwr.htm

http://www.hammondmfg.com/hist.htm
Since its modest beginnings in the basement of the family homestead 91
years
ago, Hammond has grown into two separate, medium-sized companies with
combined annual sales of over $200 Million & over 1,200 employees located
in
12 facilities around North America, the UK and Australia.

hi

thanks very much for responding

interesting links, but hopfully i won't 'have to' build one i can't
believe some company out there dosn't make either a sealed"" quite
xformer or torriod or something thats linear but not noisly
db wise or rf wise then aagain maybe i an mistaken I supposed i
could take my astron remove the transformer and put in a sutible
torioed not sure if it would be possible to do a 'direct' replacement
but perhaps if i could identify the proper type of torid and
presuming it's able to 'fit'


but its a fun experiment

This looks like a good time to bring up a transformer noise issue. I recall
something I used to do as a kid but as an adult I question the wisdom of
such a practice. I used to throw noisy transformers ( such as doorbell
transformers) into a bucket of marine ( boats) varnish. When the varnish
dried those suckers where quiet as a mouse. Was this a dangerous practice?
Could I get away with doing this to larger transformers? Speculations and
facts are most welcome.

Claude

This looks like a good time to bring up a transformer noise issue. I
recall something I used to do as a kid but as an adult I question the
wisdom of such a practice. I used to throw noisy transformers ( such as
doorbell transformers) into a bucket of marine ( boats) varnish. When the
varnish dried those suckers where quiet as a mouse. Was this a dangerous
practice? Could I get away with doing this to larger transformers?
Speculations and facts are most welcome.



It should be fine, most transformers are soaked in varnish during
manufacture.

This looks like a good time to bring up a transformer noise issue. I
recall something I used to do as a kid but as an adult I question the
wisdom of such a practice. I used to throw noisy transformers ( such as
doorbell transformers) into a bucket of marine ( boats) varnish. When the
varnish dried those suckers where quiet as a mouse. Was this a dangerous
practice? Could I get away with doing this to larger transformers?
Speculations and facts are most welcome.

It should be fine, most transformers are soaked in varnish during
manufacture.

There are specialized transformer varnishes available, which are UL
rated. I believe that they're rated both for their insulating
properties, and stability at high temperatures. Ordinary marine
varnish might or might meet the requirements, but I wouldn't bet on
their doing so.

Googling for "electrical varnish" brings up numerous links.

http://findarticles.com/p/articles/m..._n9146430/pg_1
looks like a good overview.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Mon, 3 Mar 2008 09:38:30 -0500, "Claude" wrote:


This looks like a good time to bring up a transformer noise issue. I recall
something I used to do as a kid but as an adult I question the wisdom of
such a practice. I used to throw noisy transformers ( such as doorbell
transformers) into a bucket of marine ( boats) varnish. When the varnish
dried those suckers where quiet as a mouse. Was this a dangerous practice?
Could I get away with doing this to larger transformers? Speculations and
facts are most welcome.

Claude


Basically how transformers are made in many cases. The main difference
is that usually you bake them to force dry the varnish instead of air
dry (which takes too long).

And, yes, it works well to quiet down the hummmmm...

In article , PeterD wrote:
On Mon, 3 Mar 2008 09:38:30 -0500, "Claude" wrote:


This looks like a good time to bring up a transformer noise issue. I recall
something I used to do as a kid but as an adult I question the wisdom of
such a practice. I used to throw noisy transformers ( such as doorbell
transformers) into a bucket of marine ( boats) varnish. When the varnish
dried those suckers where quiet as a mouse. Was this a dangerous practice?
Could I get away with doing this to larger transformers? Speculations and
facts are most welcome.

Claude


Basically how transformers are made in many cases. The main difference
is that usually you bake them to force dry the varnish instead of air
dry (which takes too long).

And, yes, it works well to quiet down the hummmmm...

I used to use Shellac. According to the instructions I had, they
said to use Shellac, so I did. The shellac was applied to each lamination as
it was being assembled. Mostly hands on, sticky fingers. It may also be easier
to take apart, don't know. I don't like shellac though, as it absorbs
moisture, and so does lacquer.


greg

"PeterD" wrote in message
...
On Mon, 3 Mar 2008 09:38:30 -0500, "Claude" wrote:


This looks like a good time to bring up a transformer noise issue. I
recall
something I used to do as a kid but as an adult I question the wisdom of
such a practice. I used to throw noisy transformers ( such as doorbell
transformers) into a bucket of marine ( boats) varnish. When the varnish
dried those suckers where quiet as a mouse. Was this a dangerous practice?
Could I get away with doing this to larger transformers? Speculations and
facts are most welcome.

Claude


Basically how transformers are made in many cases. The main difference
is that usually you bake them to force dry the varnish instead of air
dry (which takes too long).

And, yes, it works well to quiet down the hummmmm...


They're often put in a vacuum chamber as well which sucks out the air and
varnish moves in to replace it. You can make a suitable chamber out of a
short piece of PVC pipe capped on one end with a removable gasketted lid on
the other and evacuate it with an old fridge compressor, it doesn't really
take much vacuum to do the job. Read Sam's vacuum FAQ before you go playing
with this stuff though, an improperly made vacuum chamber is a dangerous
implosion hazard.