....How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

In article ,
says...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

--
Duncan Munro
http://www.duncanamps.com

"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

Tim Williams wrote:
"Duncan Munro" wrote in message
.. .

Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.


Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

[...]

Wow, very cool! I admire your resourcefulness...

Cheers,
Fred
--
+--------------------------------------------+
| Music: http://www3.telus.net/dogstarmusic/ |
| Projects, Vacuum Tubes & other stuff: |
| http://www.dogstar.dantimax.dk |
+--------------------------------------------+

Fred Nachbaur wrote in news:SPN8b.3122$Cu3.2102
@edtnps84:



Tim Williams wrote:
"Duncan Munro" wrote in message
.. .

Tim, when you come back from the winding jig the link above doesn't
seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.


Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

[...]

Wow, very cool! I admire your resourcefulness...

Cheers,
Fred

Let's see, a drill motor at 1000 rpm for 2.5 minutes should be about
right. (:)


r


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

Duncan Munro wrote:

In article ,
says...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

The link don't work for me either.

Patrick Turner.



--
Duncan Munro
http://www.duncanamps.com

Tim Williams wrote:

"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

That address works.
What size is the core?

I usually make an accurately cut to size timber block to fit tightly inside
the bobbin, with a 1/2 " hole in the centre to fit onto the lathe shaft,
and then I have timber/MDF plates clamped each side of the bobbin,
with appropriate holes to allow all the taps to come out.
This allows the bobbin to be turned truely, and enables neat layers with wires
all close together,
with no gaps, and NOT ONE crossed over turn, and neat flat layers to be wound.

Use fine sleeving on wires coming out of the winding, so that at least 1"
of the sleeving projects into the winding, because its
at the the entry and exit of wires through the bobbin cheeks
that arcs are most likely to happen.

Be careful to count your turns, since its so easy to place an extra layer on,
or leave one out,
and this renders the whole item a write off.

Patrick Turner.



Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"Patrick Turner" wrote in message
...

[..]
Use an old fridge compressor to create your vacuum.
Plain polyurethane will work as a varnish, and since its a bit viscous,
the vacuum chamber is needed.


why dont you just thin the varnish instead of going through the trouble of
making a vacuum? or is there some other motive here, that im missing?

Hey Tim, you have any info on making an
oil burner furnace?

I've done some bronze and Al casting and
I have a bronze ampcase in mind shaped
like a large M&M.

Maaaaaaark wrote:

"Patrick Turner" wrote in message
...

[..]
Use an old fridge compressor to create your vacuum.
Plain polyurethane will work as a varnish, and since its a bit viscous,
the vacuum chamber is needed.


why dont you just thin the varnish instead of going through the trouble of
making a vacuum? or is there some other motive here, that im missing?

If you thin down the polyurethane with say turps, then the excess
that you don't use turns to jelly a few days later, and is useless.
The viscous straight-from-the-can stuff will NOT penetrate to all air pockets
within
the tranny when using the soak method.
Heating the polyurethane and transformer together also causes jelling,
after the initial reduction in viscosity.
Vacuum impregnation is the only reliable method.

Proper electrical varnish is the best, and it can be thinned without
jelling later, but it requires 125C for 4 hours, and it gives off toxic
smells.
Waxing OPTs with wax at 100C isn't too bad because the hot wax
is low viscosity, like water, and runs right in, if the tranny is positioned
to allow air to escape from the bobbin, as the wax is drawn in by cappiliry
action
at the bottom of the wind up.
Waxing isn't bad, but vacuuming over the top of the wax makes wax fumes
fill the pump, so an additional condensor, like a stil, is needed to prevent
wax fumes
travelling to the pump.
But at least you don't have to bake the tranny after, just let the tranny
drain off.
And the tranny can be more easily stripped down and rewound if wax is used.

It is assumed that the OPT will have a large core, with fewer turns,
so winding resistances are low, so if a tube saturates, it won't
heat the OPT much, and allow wax to flow out.
Only enough impregnant is required to damp the movement of wires
with applied signal voltages.
The OPT is like a motor armature which is forced to stay still, but I assure
you
considerable magnetic forces are present, depending on the
rock and roll being fed through the transformer.

Patrick Turner

Gregg wrote:

Behold, Patrick Turner signalled from keyed 4-1000A filament:

with no gaps, and NOT ONE crossed over turn, and neat flat layers to be
wound.

There's the standard Tim. We'll make fun of you if you have ONE
crossed-over turn :-p

Well, he might err, and have a crossed wire someplace,
and that'll be the most likely point of failure, so when Tim turns 35,
and the kids tell him "dad, what's that brown smell comin from your old tube
amp?"

Really well made OPTs last and last and last.
Active over current protection can save a lot of hassles.

The problem I have with other people winding things for me is that
I don't know if they done a real great job or not.

Crossed turns create pressure spots, and perhaps a future shorted turn,
and that's a disaster.

However, when one random winds a choke, without layer winding,
they seem to last OK, and field coils in ancient radio speakers
had thousands of turns, yet have lasted well, despite the poor insulation of
1930s.
But then the random winding was done with very steady handed folks, often
women,
who fed the wire on so that turns crossing over others were at a very shallow
angle.
But neat layer winding of complex OPTs is necessary to allow the uniform
layout,
and complete absense of possible pressure spots when secondaries
are tightly wound over the top of preceeding P layers.
Crossed turns can cause bumps, which accumulate,
and cause the winding to be fatter than it should be,
thus making it hard to fit all the turns on.
Just randomly winding the primary sections would make the wire take up too
much space,
so the fill factor is low,
and the insulation wouldn't lay flat between P&S sections, and there would be

lots of pressure spots, and likely early failures, and perhaps queer
resonances.

In a small 10 watt PP tranny, where an SPS build up on the bobbin
is done using very fine wire, random winding might be OK, and many
OPTs are done this way, and the leakage inductance and capacitance
can both be low enough as finite values.
5 watt SE radio OPTs for use with a single 6V6 are often
one P and one S section. These are adequate without any or much NFB,
but with say 20 dB of NFB, the SPS build up is at least required.

Making the tranny a 25 watt+ hi-fi item to go from 10 Hz to 80 kHz
of open loop BW means that neat layer winding really is the BEST way to go,
since an SPSPSPSPS wind up is advisable, as per Williamson's ideas.

I use 6S x 5P on my 300 watters, and I get 20 Hz to 300 kHz
at 300 watts.
They are not hard to wind, because the wire size is thick,
and easily seen and managed.
I avoid the fine wire used with Williamson designs,
preferring to have a core with twice the central core area
of the Willy, and so half the turns may be used,
thus allowing lower DCR, and still maintain the low saturation F
that the Willy tranny has. And no need for a vertically divided bobbin,
because the DCR is so low, that the R difference in each 1/2 primary
becomes negligible.
I know, because I have tried both ways.

The bean counters over the last 56 years have almost all achieved one thing,
and that was to prevent any employee of the company actually
winding what Williamson said ought to be done, to achieve wide BW,
complete stability with lots of FB, and low winding losses.
The bean counters nearly always said "thinner wire, and less iron
and less labour!!"

Some custom winders, Partridge, and others, defied the el cheapo
approach.
But purchasing such wonders made you put one's $$$ where one's
beliefs were.

Patrick Turner.




--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

Any thoughs on using foil secondaries? It seems to work very well in
SMPS-transformers, I wound one for a 30 to 600 V push-pull converter.

Kimjand

Kim Johan Andersson wrote:

Any thoughs on using foil secondaries? It seems to work very well in
SMPS-transformers, I wound one for a 30 to 600 V push-pull converter.

Kimjand

I see no huge advantanges with foil secondaries,
unless you want to use thick foil, so only a few secondary turns
need be used, to get load match to
a fraction of an ohm.
But instead of paralleling such windings, they could be
seriesed to make up matches to higher 4 to 8 ohms.

A normal OPT matched for a pair of KT88
might have 5k to 8 ohms, which is
say 2,000 turns to 80 secondary turns.
The 80 turns normally are made up with 5 x 80 turn layers,
all paralleled.

If the 5 secondary layers were made with 16 turns of foil each,
and all paralleled, the impedance match is 5k to 0.32 ohms.

They could all be in series, to give 80 turns, and a match to 8 ohms.
The foil thickness plus insulation
would have to be 0.05 mm thick, so copper would be say 0.025mm thick,
and I'm not so sure the winding resistances would be any lower .
The use of rectangular wire for secs could only ever reduce Rw
marginally.

There is no magic with foil windings;
same goes for bifilar secondaries.

Patrick Turner.

"Patrick Turner" wrote in message
...
Any thoughs on using foil secondaries? It seems to work very well in
SMPS-transformers, I wound one for a 30 to 600 V push-pull converter.
^^^^
I see no huge advantanges with foil secondaries,
unless you want to use thick foil, so only a few secondary turns
need be used, to get load match to
a fraction of an ohm.

But the skin effect savings at HF are significant. Note the term I
underlined above

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

Patrick Turner wrote:


There is no magic with foil windings;
same goes for bifilar secondaries.

Sounds resonable I was mostly contemplating if foil secondaries made it
easier to wind the primary. In the SMPS transformer I did, I think it made
it an easier job. The foil was a pain to wind tightly though.

Kimjand

Tim Williams wrote:

"Patrick Turner" wrote in message
...
Any thoughs on using foil secondaries? It seems to work very well in
SMPS-transformers, I wound one for a 30 to 600 V push-pull converter.
^^^^
I see no huge advantanges with foil secondaries,
unless you want to use thick foil, so only a few secondary turns
need be used, to get load match to
a fraction of an ohm.

But the skin effect savings at HF are significant. Note the term I
underlined above

But the stray C and LL will have filtering effects far greater than skin
effects.
SMPS work at 100 kHz or above, tube amps need only go to 20 khz,
but its best they just make it to 100 kHz, for stability reasons.
The skin effects at 20 khz are sfa.

Patrick Turner.



Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

jaycee wrote:

Patrick Turner wrote:

Rich Andrews wrote:

Fred Nachbaur wrote in news:SPN8b.3122$Cu3.2102
@edtnps84:



Tim Williams wrote:
"Duncan Munro" wrote in message
.. .

Tim, when you come back from the winding jig the link above doesn't
seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.


Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

[...]

Wow, very cool! I admire your resourcefulness...

Cheers,
Fred

Let's see, a drill motor at 1000 rpm for 2.5 minutes should be about
right. (:)

No, that would apply the turns far too fast, and an ugly mess is the
result.

About a maximum speed of 2 turns per second, or 120 rpm.
I use an electric drill with fan belt pulley reduction of 5:1,
and then I have a bank of light bulb sockets in series with the drill,
so speed can be slowed to real slow.
Stop start is via a sewing machine foot switch, levaing two hands free
to
feed the wire on, over a timber rest bar about 600 mm away from the
bobbin.
Often I have to stop to adjust the wind up, to suage wires to get turns
to all
lay together,
with a piece of sharpened PLASTIC, like an amplified thumbnail,
or I have to stop, reverse a few turns to remove a crossed over turn.
Each layer is carefully checked when finished.
Insulation between layers has to be applied carefully, and
it shouldn't wrinkle up when succeeding layers are wound.
tension in the wire is easy adusted by feeding wire through the hand,
not to tight, but not too loose, and its practice which wises one up to
what is really required.

Practice makes perfect, and its a case of self discipline, and more
practice, and more practice, and good mental picture to start with.
Its like bricklaying, shearing sheep, or fitting doors to a house,
one takes time to get the knack, the speed, the neatness, the accuracy,
the skill. Really good tranny winders with a nice machine would wind an
original Williamson
is a couple of hours.
I take about all day.
The terminations, fitting E&I lams, bolting up,
and varnishing all take time, so maybe 2.5 days all up.

Patrick Turner.


--
"Any sufficiently advanced technology is indistinguishable from
magic."

Arthur C. Clarke (1917 - ), "Technology and the Future"

if you wanne see another diy winder, look here :

http://users.belgacom.net/cse_systems/winder.htm

since these pics were shot i replaced the dancer mechanism by the
tensioner of the older winder
works great, only need some way of measuring the tension

the driver electronics was not stable enough so i replaced the complete
driver with the original driver pcb and a pc interface
has current sensing and PWM current limiting build in

tension is better under control now and wire is very snug around the
core, no more bulging
traverse is computer controlled so no crossed wires at all

at 6 rpm it takes a while but i don't have to watch it
runs by itself, just punch in the number of turns

minor issue, some hysteresis on the traverse if direction is changed
no problem if you insert isolation between each layer

jef

That machine looks great, and its beyond my talents to construct something like
that,
But then I have always been ok with using tools of many types,
so the old way will do. Winding the bobbin up is only part
of the process.

Happy winderations,

Patrick Turneration.

jim wrote:

"Tim Williams" wrote in message
...
"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Hi. Tim,
I made a hand winding rig a few years ago. Total cost about $20 .. Looks
nothing like yours but the principle is the same.
2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day. Wouldn't
bother about a power drive. Without tension control and auto traverse you
won't get many more turns an hour out of it and if you're only turning up a
few trannies, the complication is not worth the trouble. I've got an
electric one, (home made) but rarely use it...
Don't even think about it without a turns counter.... After 4000 turns, the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!
My rig uses a simple resettable mechanical counter driven by a pushrod and
an eccentric on the bobbin spindle. Reads up to 10,000... Could have worked
it with just a peg attatched to the spindle to hit the counter's operating
arm but it would only work one way doing that. Using an eccentric and a
pushrod means it counts in both directions.
No scanner, no digicamera, otherwise I'd mail you a picture...
I've got a spare counter if you want it, cost/mail/shipping/handling free,
but it says Made in USA on it and I only paid about $5 for it in the UK.
No manufacturers name on it though. Google.. 'counter' and see what comes
out.... Radio Shack/Home Depot .. look around... You get stuck, mail me ...
and I'll send you this spare one I got..
Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't turn
the handle, tension the wire and hold the rig down at the same time unless
you've got more hands than I have..

regards
jim

I'd hate to have to crank the handle by hand, as well as feed the wire
on with a single hand, and gets the turns to lay properly, without gaps, and the
correct
and full number of turns for each and every layer.
So I got an electric drill in a box with a flex drive, lightbulbs in series to
control speed,
and foot switch.
Now those who are so stingy and won't buy the cheapest electric drill
to suit the purpose then they could use bicycle parts to make a drive system,
and pedal their way to Audio Nivirna, if they can balance on saddle,
and play with the wires with both hands at the same time.
Fat guys take note!!!! you can wind your way to a better figure in 4,500 turns!

In the Oz outback, the remote sheep stations used to have
pedal operated radios, for kids to use for school lessons,
and for general communications.
All tube powered.

Ever see an overweight farm person in 1948?
Never.

Patrick Turner.

"Tim Williams" wrote in message
...
"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't seem
to work. Not sure if it was an upper/lower case problem or something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Hi. Tim,
I made a hand winding rig a few years ago. Total cost about $20 .. Looks
nothing like yours but the principle is the same.
2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day. Wouldn't
bother about a power drive. Without tension control and auto traverse you
won't get many more turns an hour out of it and if you're only turning up a
few trannies, the complication is not worth the trouble. I've got an
electric one, (home made) but rarely use it...
Don't even think about it without a turns counter.... After 4000 turns, the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!
My rig uses a simple resettable mechanical counter driven by a pushrod and
an eccentric on the bobbin spindle. Reads up to 10,000... Could have worked
it with just a peg attatched to the spindle to hit the counter's operating
arm but it would only work one way doing that. Using an eccentric and a
pushrod means it counts in both directions.
No scanner, no digicamera, otherwise I'd mail you a picture...
I've got a spare counter if you want it, cost/mail/shipping/handling free,
but it says Made in USA on it and I only paid about $5 for it in the UK.
No manufacturers name on it though. Google.. 'counter' and see what comes
out.... Radio Shack/Home Depot .. look around... You get stuck, mail me ...
and I'll send you this spare one I got..
Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't turn
the handle, tension the wire and hold the rig down at the same time unless
you've got more hands than I have..

regards
jim

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't
seem
to work. Not sure if it was an upper/lower case problem or
something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide
Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Hi. Tim,
I made a hand winding rig a few years ago. Total cost about $20 ..
Looks
nothing like yours but the principle is the same.
2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day. Wouldn't
bother about a power drive. Without tension control and auto traverse
you
won't get many more turns an hour out of it and if you're only turning
up a
few trannies, the complication is not worth the trouble. I've got an
electric one, (home made) but rarely use it...
Don't even think about it without a turns counter.... After 4000 turns,
the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!
My rig uses a simple resettable mechanical counter driven by a pushrod
and
an eccentric on the bobbin spindle. Reads up to 10,000... Could have
worked
it with just a peg attatched to the spindle to hit the counter's
operating
arm but it would only work one way doing that. Using an eccentric and a
pushrod means it counts in both directions.
No scanner, no digicamera, otherwise I'd mail you a picture...
I've got a spare counter if you want it, cost/mail/shipping/handling
free,
but it says Made in USA on it and I only paid about $5 for it in the
UK.
No manufacturers name on it though. Google.. 'counter' and see what
comes
out.... Radio Shack/Home Depot .. look around... You get stuck, mail me
....
and I'll send you this spare one I got..
Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't
turn
the handle, tension the wire and hold the rig down at the same time
unless
you've got more hands than I have..

regards
jim

I'd hate to have to crank the handle by hand, as well as feed the wire
on with a single hand, and gets the turns to lay properly, without gaps,
and the
correct
and full number of turns for each and every layer.
So I got an electric drill in a box with a flex drive, lightbulbs in
series to
control speed,
and foot switch.
Now those who are so stingy and won't buy the cheapest electric drill
to suit the purpose then they could use bicycle parts to make a drive
system,
and pedal their way to Audio Nivirna, if they can balance on saddle,
and play with the wires with both hands at the same time.
Fat guys take note!!!! you can wind your way to a better figure in 4,500
turns!

Now, look...
I don't need to play with myself with both hands... Stingy ???? Tony has
allowed me to keep almost 10% of my wages ,after tax, this year, so I am
virtually rich....A Walmart drill has only two settings.. on or off.....
and trying to achieve constant tension with 42SWG and a rubber band is like
trying to hit Jupiter by throwing a big stone at it,
Fat guys on bicycles are no better off....... Look! We're fat.. we're
British, and we probably invented the bicycle.. do you not think we would
have found a way to wind a transformer with a bicycle by now, if it was
humanlly possible ??? The most creative spot on the globe !!! We're fifty
years ahead of you.....Sherlock Holmes tried it.... 46 orgasms and he got a
2A heater tranny.....

In the Oz outback, the remote sheep stations used to have
pedal operated radios, for kids to use for school lessons,
and for general communications.
All tube powered.

C'mon ... We're trying to step forward here... You may have invented the
kangaroo but it is hardly something to be proud of. It's tall, agressive,
runs quick and tastes crap. The sheep is a British invention.

Ever see an overweight farm person in 1948?
Never.

Couldn't catch the kangaroos. .
regards
jim

Patrick Turner.

jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
"Duncan Munro" wrote in message
.. .
Tim, when you come back from the winding jig the link above doesn't
seem
to work. Not sure if it was an upper/lower case problem or
something,
but the variations I tried all gave an error page.

Humm... *brain fart* looks like I forgot it's not on the World Wide
Web
(www). :^)
http://webpages.charter.net/dawill/Images/80W_OPT.jpg should work.

As for the jig: http://webpages.charter.net/dawill/Images/Jig.jpg
(Sorry, crummy webcam photo.) Now I just have to turn that handle
a good 2,500 times and I'm done!

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Hi. Tim,
I made a hand winding rig a few years ago. Total cost about $20 ..
Looks
nothing like yours but the principle is the same.
2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day. Wouldn't
bother about a power drive. Without tension control and auto traverse
you
won't get many more turns an hour out of it and if you're only turning
up a
few trannies, the complication is not worth the trouble. I've got an
electric one, (home made) but rarely use it...
Don't even think about it without a turns counter.... After 4000 turns,
the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!
My rig uses a simple resettable mechanical counter driven by a pushrod
and
an eccentric on the bobbin spindle. Reads up to 10,000... Could have
worked
it with just a peg attatched to the spindle to hit the counter's
operating
arm but it would only work one way doing that. Using an eccentric and a
pushrod means it counts in both directions.
No scanner, no digicamera, otherwise I'd mail you a picture...
I've got a spare counter if you want it, cost/mail/shipping/handling
free,
but it says Made in USA on it and I only paid about $5 for it in the
UK.
No manufacturers name on it though. Google.. 'counter' and see what
comes
out.... Radio Shack/Home Depot .. look around... You get stuck, mail me
...
and I'll send you this spare one I got..
Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't
turn
the handle, tension the wire and hold the rig down at the same time
unless
you've got more hands than I have..

regards
jim

I'd hate to have to crank the handle by hand, as well as feed the wire
on with a single hand, and gets the turns to lay properly, without gaps,
and the
correct
and full number of turns for each and every layer.
So I got an electric drill in a box with a flex drive, lightbulbs in
series to
control speed,
and foot switch.
Now those who are so stingy and won't buy the cheapest electric drill
to suit the purpose then they could use bicycle parts to make a drive
system,
and pedal their way to Audio Nivirna, if they can balance on saddle,
and play with the wires with both hands at the same time.
Fat guys take note!!!! you can wind your way to a better figure in 4,500
turns!

Now, look...
I don't need to play with myself with both hands... Stingy ???? Tony has
allowed me to keep almost 10% of my wages ,after tax, this year, so I am
virtually rich....A Walmart drill has only two settings.. on or off.....
and trying to achieve constant tension with 42SWG and a rubber band is like
trying to hit Jupiter by throwing a big stone at it,

Thats where the use of a light bulb in series with the drill motor
comes in handy to control speed..
But I have wound a few chokes with 0.125mm dia wire,
no worries, with 8,000 turns.
Just a couple of hours work run up a nice high inductance choke.


Fat guys on bicycles are no better off....... Look! We're fat.. we're
British, and we probably invented the bicycle.. do you not think we would
have found a way to wind a transformer with a bicycle by now, if it was
humanlly possible ???

Well, in asia they do. Its like tredle powered sewing machines.....
They all slim over there...

The most creative spot on the globe !!! We're fifty
years ahead of you.....Sherlock Holmes tried it.... 46 orgasms and he got a
2A heater tranny.....

In the Oz outback, the remote sheep stations used to have
pedal operated radios, for kids to use for school lessons,
and for general communications.
All tube powered.

C'mon ... We're trying to step forward here... You may have invented the
kangaroo but it is hardly something to be proud of. It's tall, agressive,
runs quick and tastes crap. The sheep is a British invention.

But we run mainly merinos, from spain, and they like Oz conditions.



Ever see an overweight farm person in 1948?
Never.

Couldn't catch the kangaroos. .
regards
jim

The old roo can sure outpace a man, even if he's on a bicycle.

But we kill hundreds each week on the roads here.
Its the major cause of the panel beating industry in regional areas
where I live.
Its really bad news if you hit a big one at night, out in the middle
of knowhere, and he comes over the bonnet, through the windshield,
and into the cab,
and in his death agony, kicks the hell out of you, your passengers,
and leaves the inside of the car like an abattoir.

Patrick Turner.



Patrick Turner.

"jim" wrote in message
...
I made a hand winding rig a few years ago. Total cost about $20 .. Looks
nothing like yours but the principle is the same.

Total cost: scrap. Good enough

2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day.

I don't doubt it. I started winding yesterday, and I've got a table
drawn up for logging turns per layer, current total is 450T over 4 layers
for the first primary section, a bit less per layer than I had hoped.
I put the last two of those layers on in just 20 minutes.

Don't even think about it without a turns counter.... After 4000 turns,
the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!

*click* BANG sound of jim thudding on the floor
That's exactly why I drew up the winding schedule...

My rig uses a simple resettable mechanical counter driven by a pushrod and
an eccentric on the bobbin spindle.

I'm young and already eccentric, so I need no mechanical counter, I have
one clicking away in my head, it gets very annoying and keeps me up at
night...

You get stuck, mail me ... and I'll send you this spare one I got..

Thanks but 110 turns per layer shouldn't be a problem for my ol' clunker
up in there...

Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't turn
the handle, tension the wire and hold the rig down at the same time unless
you've got more hands than I have..

I have two more hands than you do, remember I'm young, I hold it down
with one foot, tension the wire with the right hand, and turn with the
left, all the while doodling away schematics with my right toe...

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

Tim Williams wrote:

"jim" wrote in message
...
I made a hand winding rig a few years ago. Total cost about $20 .. Looks
nothing like yours but the principle is the same.

Total cost: scrap. Good enough

2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day.

I don't doubt it. I started winding yesterday, and I've got a table
drawn up for logging turns per layer, current total is 450T over 4 layers
for the first primary section, a bit less per layer than I had hoped.
I put the last two of those layers on in just 20 minutes.

Don't even think about it without a turns counter.... After 4000 turns,
the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!

*click* BANG sound of jim thudding on the floor
That's exactly why I drew up the winding schedule...

My rig uses a simple resettable mechanical counter driven by a pushrod and
an eccentric on the bobbin spindle.

I'm young and already eccentric, so I need no mechanical counter, I have
one clicking away in my head, it gets very annoying and keeps me up at
night...

You get stuck, mail me ... and I'll send you this spare one I got..

Thanks but 110 turns per layer shouldn't be a problem for my ol' clunker
up in there...

Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't turn
the handle, tension the wire and hold the rig down at the same time unless
you've got more hands than I have..

I have two more hands than you do, remember I'm young, I hold it down
with one foot, tension the wire with the right hand, and turn with the
left, all the while doodling away schematics with my right toe...

Tim


For real difficult to do designs, I hire one of the
Indian Krishna Gods, who has an elephant's nose,
and about 50 arms and hands, along with other features
not appropriate for winding trannies.

I have to arrange for this well in advance,
and apply by letter to the Dept of God Of Triodes, Sth Division.

Patrick Turner.


--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"Tim Williams" wrote in message
...
"jim" wrote in message
...
I made a hand winding rig a few years ago. Total cost about $20 ..
Looks
nothing like yours but the principle is the same.

Total cost: scrap. Good enough

Couldn't you do it cheaper ? I'd ask for my money back. I think you got
ripped off.

2000 turns an hour is achievable. Add on time for insulating layers and
terminations and you can easily turn out a tranny in a day.

I don't doubt it. I started winding yesterday, and I've got a table
drawn up for logging turns per layer, current total is 450T over 4 layers
for the first primary section, a bit less per layer than I had hoped.
I put the last two of those layers on in just 20 minutes.

You should be far quicker than me. I can no longer see anything thinner than
the AC cable which supplies my house... Had to learn Braille. I now do
everything by feel and touch..and the wife tells me what the counter says..

Don't even think about it without a turns counter.... After 4000 turns,
the
phone rings and you lose track of where you were ! .... OHHH.. **** !!!
SHOOT ME, SOMEBODY !!!!

*click* BANG sound of jim thudding on the floor

O.K.. I,m dead..

That's exactly why I drew up the winding schedule...

My rig uses a simple resettable mechanical counter driven by a pushrod
and
an eccentric on the bobbin spindle.

I'm young and already eccentric, so I need no mechanical counter, I have
one clicking away in my head, it gets very annoying and keeps me up at
night...

You can't be young AND eccentric... Young eccentrics can get themselves
locked up as revolutionaries or potential terrorists. Being old and
eccentric is normal. It's called Altzheimers Couldn't manage without a
counter..Education was very bad years ago and nobody ever told us what came
after nine. Over nine was just called 'a lot' I had to go to evening
classes to learn the rest. Now, I am very old and the memory is failing so
I forget what order all these numbers go in and fall asleep. Wish I was
young again and had learnt multiplication and division

You get stuck, mail me ... and I'll send you this spare one I got..

Thanks but 110 turns per layer shouldn't be a problem for my ol' clunker
up in there...

Only other comment.. NAIL THE RIG DOWN ON TO THE BENCH.....You can't
turn
the handle, tension the wire and hold the rig down at the same time
unless
you've got more hands than I have..

I have two more hands than you do, remember I'm young, I hold it down
with one foot, tension the wire with the right hand, and turn with the
left, all the while doodling away schematics with my right toe...

Be careful winding very large trannies. Permanent disfigurement may occur
and you could spend the rest of your life, stuck in the winding position,
dragging yourself around with the left side of your body massively
overdeveloped and no ability to see anything over 15" away from you.
Excessive tension on thicker gauge wire is also bad. I gradually amputated
three of the fingers on my right hand over a 9 hour wind up of a big choke a
few years back
regards
jim

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms



Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of Tudor
times, when body piercing meant something else other than wearing earrings.
I can well understand those immortal words in her case, but who's Ned ?
regards
jim

jim wrote:

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of Tudor
times, when body piercing meant something else other than wearing earrings.
I can well understand those immortal words in her case, but who's Ned ?
regards
jim

Tim left out part of the quote, and it should have been,

"No foot longs, when 6" used twice will do!"

Or it could have been, "No foot longs, take that thing away, damn you!"

Patrick Turner

Who's Ned Flanders ?

Homer Simpson's next door neighbor. One of those annoyingly religious
born again guys.....

jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to
impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of
Tudor
times, when body piercing meant something else other than wearing
earrings.
I can well understand those immortal words in her case, but who's Ned ?
regards
jim

Tim left out part of the quote, and it should have been,

"No foot longs, when 6" used twice will do!"

Or it could have been, "No foot longs, take that thing away, damn you!"

Patrick Turner


We're back to that classic definition of 'foreplay' ... 'Grab hold of the
headboard and brace yerself, girl ' !!
regards

Ah, that's the british knight in shining armour for yer.
Hasn't even the time to take the bloodstained boots off.


jim

But I thought the Cassanova foreplay method was,
after several days of non stop bonking,

"Youse a'wake?"

Patrick Turner.

jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube
amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to
impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of
Tudor
times, when body piercing meant something else other than wearing
earrings.
I can well understand those immortal words in her case, but who's
Ned ?
regards
jim

Tim left out part of the quote, and it should have been,

"No foot longs, when 6" used twice will do!"

Or it could have been, "No foot longs, take that thing away, damn
you!"

Patrick Turner


We're back to that classic definition of 'foreplay' ... 'Grab hold of
the
headboard and brace yerself, girl ' !!
regards

Ah, that's the british knight in shining armour for yer.
Hasn't even the time to take the bloodstained boots off.


jim

But I thought the Cassanova foreplay method was,
after several days of non stop bonking,

"Youse a'wake?"

Patrick Turner.

You all thought knights wore spurs to kick horses and make them go
faster....... Spurs were actually developed to provide a better grip on a
mattress. Another British invention. If she was good enough to be
holding firmly onto the headboard it would be a shame to disappoint her.....
Today we use crampons.. what a wonderfully agressive word that is !! ..
CRAMPONS !! .. Shoes with nails in the soles... Bugger yerself up climbing
mountains in them, if you want.... or just put it about on the slopes that
you have a pair of CRAMPONS and the evening could be fairly sweet.....
I don't wish to get too rude here, but , years ago, in my teens, I remember
lying in bed listening to a headboard , in the next room, banging violently
on the wall, behind me and a male voice shouting, repeatedly.... BARK, !!
YOU *******!!!!!
Could this have been a moment in history that I missed ?? The creation of
the all British , all comers, universal, CRAMPON !!
I must log this down in the Interthing.... Jim heard it in 1967..... It;s
British, thank God, the Empire, Victoria and anybody else...... We invented
the CRAMPON....!!!!!!!!!!.

regards
jim

Ah, now I know why I drive past so many ripped up and shreded
mattresses littering the English Countryside, in all its bucolic grandeur,
its the British Mating Habits.....
No wonder pomme mental hospitals are so full of sheilas,
and the birthrate is so low.

Patrick Turner.

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to
impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of
Tudor
times, when body piercing meant something else other than wearing
earrings.
I can well understand those immortal words in her case, but who's Ned ?
regards
jim

Tim left out part of the quote, and it should have been,

"No foot longs, when 6" used twice will do!"

Or it could have been, "No foot longs, take that thing away, damn you!"

Patrick Turner


We're back to that classic definition of 'foreplay' ... 'Grab hold of the
headboard and brace yerself, girl ' !!
regards
jim

jim wrote:

Sensible stuff...
I have a guy who winds stuff for Maplin/RS by the thousand. .. Dave... He's
in his fifties and has done this stuff for years. He's done odd
chokes/trannies for me White spirit/turpentine based polyurethane wood
varnish from Home Depot etc.?.. Dave says it's OK... I say, but Dave, the
wire is polyurethane insulated ? What about the solvent ? If this all
melts together, I could end up with a quick bang one turn tranny....Dave
says I will have no problems.. Any thoughts ??

Most good quality winding wire is NOT polurethane insulated, but has
some polyistermide coating, which is far more temperature resistant
than polurethane. It is quite stable in thre presence of electrical vanishes,
even during the 4 hr baking process, when the rather nasty smelling
solvents are driven off.

afaik, furniture grade liquid polyurethane is OK for cool running
power trannies. Its solvents don't affect the high temp wire.

There are trannies wound with polurethane coated wire, and these regularly
fail when they over heat, and they often tempt fate because they
simply don't run at a low enough B, and with low enough copper losses
to ensure cool running.

For each 10C rise in temp, expect the reliability to fall 10%.
Its a general rule of thumb for all transformers, and SS electronics.

Tubes run hot, and different numbers apply.



OR...... There are quick drying water or spirit based polyurethanes
available now. How about varnishing up each layer of windings as you go
rather than trying to impregnate the whole bobbin when you've finished ??

Its very messy to do this properly as you go.
Baking the tranny is still required.
Its better to vacuum impregnate the varnish, and then bake the tranny.

Don't use water based anything near any transformers.
Its only OK for the kiddies toys.


Polythene insulation...... the carry home bag from the hypermarket.... Any
thoughts on cling film...looks attractive in that it ties the windings
down...

Polythene is only OK for OPTs which
won't heat up, if well designed, even when overloaded with a tube which has
saturated.
But there is NO excuse for building an amp whose tubes might
kill the OPT if they do saturate. Use active over current sensing,
and have the amp turn off politely in a fault, and not cause smoke,
followed by a wallet emptying repair experience..

Polythene is a no-no for power trannies.
It melts at 110C.
The tranny won't stand impregnation and baking after windup.
Use only materials which can take 200C or better, so mylars,
and paper and teflon are OK.
Papers are basically lignum and celulose, or natural fibre,
and the impregnant needs to penetrate it fully, so when baking is complete,
the fibre filled material is something far more rugged than paper on its own.

Patrick Turner.


regards
jim

"jim" wrote in message
...
He's done odd
chokes/trannies for me White spirit/turpentine based polyurethane wood
varnish from Home Depot etc.?.. Dave says it's OK... I say, but Dave,
the
wire is polyurethane insulated ? What about the solvent ? If this all
melts together, I could end up with a quick bang one turn tranny....Dave
says I will have no problems.. Any thoughts ??

The varnish sets up and is resistant to the solvent after drying.
Just like concrete is made with water but isn't washed away.
Laquer, OTOH, is always soluble in alcohol, so careful with the whiskey
when you're winding with that...

OR...... There are quick drying water or spirit based polyurethanes
available now. How about varnishing up each layer of windings as you go
rather than trying to impregnate the whole bobbin when you've finished ??

Could try that too. Would probably work well, if slow because you have
to wait a good number of hours between layers.

Polythene insulation...... the carry home bag from the hypermarket.... Any
thoughts on cling film...looks attractive in that it ties the windings
down...

Gnaw, both are less than a half thou thick, that's .013mm for you out
there in non-USA-land, however some heavy packing type bags are good
enough, I'm using a 2.2mil LDPE bag for between layers..

Tim

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms

"Patrick Turner" wrote in message
...


jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube
amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to
impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms


Who's Ned Flanders ? I've heard of Moll Flanders, the showgirl of
Tudor
times, when body piercing meant something else other than wearing
earrings.
I can well understand those immortal words in her case, but who's
Ned ?
regards
jim

Tim left out part of the quote, and it should have been,

"No foot longs, when 6" used twice will do!"

Or it could have been, "No foot longs, take that thing away, damn
you!"

Patrick Turner


We're back to that classic definition of 'foreplay' ... 'Grab hold of
the
headboard and brace yerself, girl ' !!
regards

Ah, that's the british knight in shining armour for yer.
Hasn't even the time to take the bloodstained boots off.


jim

But I thought the Cassanova foreplay method was,
after several days of non stop bonking,

"Youse a'wake?"

Patrick Turner.


You all thought knights wore spurs to kick horses and make them go
faster....... Spurs were actually developed to provide a better grip on a
mattress. Another British invention. If she was good enough to be
holding firmly onto the headboard it would be a shame to disappoint her.....
Today we use crampons.. what a wonderfully agressive word that is !! ..
CRAMPONS !! .. Shoes with nails in the soles... Bugger yerself up climbing
mountains in them, if you want.... or just put it about on the slopes that
you have a pair of CRAMPONS and the evening could be fairly sweet.....
I don't wish to get too rude here, but , years ago, in my teens, I remember
lying in bed listening to a headboard , in the next room, banging violently
on the wall, behind me and a male voice shouting, repeatedly.... BARK, !!
YOU *******!!!!!
Could this have been a moment in history that I missed ?? The creation of
the all British , all comers, universal, CRAMPON !!
I must log this down in the Interthing.... Jim heard it in 1967..... It;s
British, thank God, the Empire, Victoria and anybody else...... We invented
the CRAMPON....!!!!!!!!!!.

regards
jim

Sensible stuff...
I have a guy who winds stuff for Maplin/RS by the thousand. .. Dave... He's
in his fifties and has done this stuff for years. He's done odd
chokes/trannies for me White spirit/turpentine based polyurethane wood
varnish from Home Depot etc.?.. Dave says it's OK... I say, but Dave, the
wire is polyurethane insulated ? What about the solvent ? If this all
melts together, I could end up with a quick bang one turn tranny....Dave
says I will have no problems.. Any thoughts ??
OR...... There are quick drying water or spirit based polyurethanes
available now. How about varnishing up each layer of windings as you go
rather than trying to impregnate the whole bobbin when you've finished ??
Polythene insulation...... the carry home bag from the hypermarket.... Any
thoughts on cling film...looks attractive in that it ties the windings
down...
regards
jim

jim wrote:

"Patrick Turner" wrote in message
...


jim wrote:

Sensible stuff...

Thanks.
What about cling film..... you tried it. ?? Like the mechanical
properties..
regards
jim

Well no. The supermakets have sfa which is suitable for
transformer winding.

Patrick Turner.

"Patrick Turner" wrote in message
...


jim wrote:

Sensible stuff...
I have a guy who winds stuff for Maplin/RS by the thousand. .. Dave...
He's
in his fifties and has done this stuff for years. He's done odd
chokes/trannies for me White spirit/turpentine based polyurethane
wood
varnish from Home Depot etc.?.. Dave says it's OK... I say, but Dave,
the
wire is polyurethane insulated ? What about the solvent ? If this all
melts together, I could end up with a quick bang one turn
tranny....Dave
says I will have no problems.. Any thoughts ??

Most good quality winding wire is NOT polurethane insulated, but has
some polyistermide coating, which is far more temperature resistant
than polurethane. It is quite stable in thre presence of electrical
vanishes,
even during the 4 hr baking process, when the rather nasty smelling
solvents are driven off.

afaik, furniture grade liquid polyurethane is OK for cool running
power trannies. Its solvents don't affect the high temp wire.

There are trannies wound with polurethane coated wire, and these regularly
fail when they over heat, and they often tempt fate because they
simply don't run at a low enough B, and with low enough copper losses
to ensure cool running.

For each 10C rise in temp, expect the reliability to fall 10%.
Its a general rule of thumb for all transformers, and SS electronics.

Tubes run hot, and different numbers apply.



OR...... There are quick drying water or spirit based polyurethanes
available now. How about varnishing up each layer of windings as you go
rather than trying to impregnate the whole bobbin when you've finished
??

Its very messy to do this properly as you go.
Baking the tranny is still required.
Its better to vacuum impregnate the varnish, and then bake the tranny.

Don't use water based anything near any transformers.
Its only OK for the kiddies toys.


Polythene insulation...... the carry home bag from the hypermarket....
Any
thoughts on cling film...looks attractive in that it ties the windings
down...

Polythene is only OK for OPTs which
won't heat up, if well designed, even when overloaded with a tube which
has
saturated.
But there is NO excuse for building an amp whose tubes might
kill the OPT if they do saturate. Use active over current sensing,
and have the amp turn off politely in a fault, and not cause smoke,
followed by a wallet emptying repair experience..

Polythene is a no-no for power trannies.
It melts at 110C.
The tranny won't stand impregnation and baking after windup.
Use only materials which can take 200C or better, so mylars,
and paper and teflon are OK.
Papers are basically lignum and celulose, or natural fibre,
and the impregnant needs to penetrate it fully, so when baking is
complete,
the fibre filled material is something far more rugged than paper on its
own.

Patrick Turner.




Thanks.
What about cling film..... you tried it. ?? Like the mechanical
properties..
regards
jim

Tim, find a Robinair or J/B or Ritchie vacuum pump made for A/C service men

you will find it's a big help



"Tim Williams" wrote in message
...
...How crazy am I? I've started on an OPT for the sweep tube amp...
http://www.charter.net/dawill/Images/80W_OPT.jpg
And yes I'm going to find a compressor and vacuum chamber to impregnate
the thing. Y'say garden-variety satin polyurethane will work?

Tim (off to make a winding jig)

--
In the immortal words of Ned Flanders: "No foot longs!"
Website @ http://webpages.charter.net/dawill/tmoranwms