Maker Pro
Maker Pro

see picture, fm tuner, wax on components ?

D

Don Bruder

Jan 1, 1970
0
"phil" <[email protected]> said:
My fm tuner circuit is very strange, it has wax all over some parts of
it and inside a coil there is also a spunge which it seems was soaked
in wax.

http://www.geocities.com/myelectronicsrevision/fmtuner.jpg

Any ideas what all this wax is for ?

It might not be ultra-stong, but it's sufficient to prevent various
motion and/or deformation of controls/parts that are adjustable, or
could be "thrown out of whack" by being moved, squashed, or otherwise
rearranged.

If you look closely, you'll probably notice that the majority of the
"waxed" pieces are either adjustable (probably little square metal
"cans" with a screwdriver hole in the top. Those are slug-tuned coils,
and turning the slug, deliberately or otherwise, *WILL* alter the tuning
capability. Ditto little "flat-pack" widgets with what look like screws
- Tiny trimmer capacitors.) or would be sensitive to being deformed,
such as naked coils, like the one you describe as being stuffed with a
wax soaked sponge. These guys can change value dramatically if bent,
stretched, or otherwise altered even slightly, again changing the
tuning, and probably not for the better - Unless you *WANT* the radio to
cease picking up the FM broadcast band, and instead, start tuning in Ham
radio conversations, TV soundtracks, perhaps even cops, or in ungodly
improbable circumstances, even cell phone transmissions.

The wax is all about "locking down" the factory tuning to prevent
accidental changes that would knock the radio "out of alignment"
 
P

phil

Jan 1, 1970
0
It might not be ultra-stong, but it's sufficient to prevent various
motion and/or deformation of controls/parts that are adjustable, or
could be "thrown out of whack" by being moved, squashed, or otherwise
rearranged.

If you look closely, you'll probably notice that the majority of the
"waxed" pieces are either adjustable (probably little square metal
"cans" with a screwdriver hole in the top. Those are slug-tuned coils,
and turning the slug, deliberately or otherwise, *WILL* alter the tuning
capability. Ditto little "flat-pack" widgets with what look like screws
- Tiny trimmer capacitors.) or would be sensitive to being deformed,
such as naked coils, like the one you describe as being stuffed with a
wax soaked sponge. These guys can change value dramatically if bent,
stretched, or otherwise altered even slightly, again changing the
tuning, and probably not for the better - Unless you *WANT* the radio to
cease picking up the FM broadcast band, and instead, start tuning in Ham
radio conversations, TV soundtracks, perhaps even cops, or in ungodly
improbable circumstances, even cell phone transmissions.

The wax is all about "locking down" the factory tuning to prevent
accidental changes that would knock the radio "out of alignment"

How is it applied, do they pay someone with a candle to drop wax drops
at the end of the production line ?
 
D

Don Bruder

Jan 1, 1970
0
[QUOTE=""phil said:
It might not be ultra-stong, but it's sufficient to prevent various
motion and/or deformation of controls/parts that are adjustable, or
could be "thrown out of whack" by being moved, squashed, or otherwise
rearranged.

If you look closely, you'll probably notice that the majority of the
"waxed" pieces are either adjustable (probably little square metal
"cans" with a screwdriver hole in the top. Those are slug-tuned coils,
and turning the slug, deliberately or otherwise, *WILL* alter the tuning
capability. Ditto little "flat-pack" widgets with what look like screws
- Tiny trimmer capacitors.) or would be sensitive to being deformed,
such as naked coils, like the one you describe as being stuffed with a
wax soaked sponge. These guys can change value dramatically if bent,
stretched, or otherwise altered even slightly, again changing the
tuning, and probably not for the better - Unless you *WANT* the radio to
cease picking up the FM broadcast band, and instead, start tuning in Ham
radio conversations, TV soundtracks, perhaps even cops, or in ungodly
improbable circumstances, even cell phone transmissions.

The wax is all about "locking down" the factory tuning to prevent
accidental changes that would knock the radio "out of alignment"

How is it applied, do they pay someone with a candle to drop wax drops
at the end of the production line ?
[/QUOTE]

More likely, the whole board sits in a mold-box, and something filled
with hot wax just goes <SPOOGE> in the general direction of the board as
it goes by on the line, without much (if any) interest in exactly where
any overflow ends up. Wax isn't conductive, so it really doesn't matter
on any level (other than cosmetic considerations) where any "spatters"
might land. Of coure, a more sophisicated production line could use
something that "spooges" through multiple nozzles, with pinpoint
accuracy. But since most electronic boards are hidden inside some sort
of pretty casing, the typical consumer is never going to see how pretty
it is or isn't. Only "weirdos" like you and me, who open up our
electronic toys to see what makes them tick. :)

Amusement value:
The legend "No user servicable parts inside" that appears on so many
electronic widgets. Guess what, manufacturers... Some of us CAN figure
out how to run a soldering iron, meter, and other electronic servicing
equipment, and can indeed service that "unservicable" device, so your
statement about no user servicable parts is pure baloney. :)

I've always been amused by that one... Dunno why, but it tickles my
funnybone.
 
M

michael turner

Jan 1, 1970
0
How is it applied, do they pay someone with a candle to drop wax drops
at the end of the production line ?

Years ago I used to work in a repair-shop repairing stuff like that.
And that's exactly what we did to lock-down moveable and sensitive
components.
 
J

Jerry Greenberg

Jan 1, 1970
0
The link you gave is not availble.

The wax is used on critical components to reduce the effects of
vibration to cause microphonic effects with vibration or movement.
This was done especialy in high frequency circuits, to dampen the
microphonics, and to also keep the components mechanicaly aligned. The
physical positions of many of these compoenents is critical for the
alignment of the circuits involved. I would not advise to mess with
this.

Jerry G.
http://www.zoom-one.com

--




Don Bruder said:
[QUOTE=""phil said:
It might not be ultra-stong, but it's sufficient to prevent various
motion and/or deformation of controls/parts that are adjustable, or
could be "thrown out of whack" by being moved, squashed, or otherwise
rearranged.

If you look closely, you'll probably notice that the majority of the
"waxed" pieces are either adjustable (probably little square metal
"cans" with a screwdriver hole in the top. Those are slug-tuned coils,
and turning the slug, deliberately or otherwise, *WILL* alter the tuning
capability. Ditto little "flat-pack" widgets with what look like screws
- Tiny trimmer capacitors.) or would be sensitive to being deformed,
such as naked coils, like the one you describe as being stuffed with a
wax soaked sponge. These guys can change value dramatically if bent,
stretched, or otherwise altered even slightly, again changing the
tuning, and probably not for the better - Unless you *WANT* the radio to
cease picking up the FM broadcast band, and instead, start tuning in Ham
radio conversations, TV soundtracks, perhaps even cops, or in ungodly
improbable circumstances, even cell phone transmissions.

The wax is all about "locking down" the factory tuning to prevent
accidental changes that would knock the radio "out of alignment"

How is it applied, do they pay someone with a candle to drop wax drops
at the end of the production line ?

More likely, the whole board sits in a mold-box, and something filled
with hot wax just goes <SPOOGE> in the general direction of the board as
it goes by on the line, without much (if any) interest in exactly where
any overflow ends up. Wax isn't conductive, so it really doesn't matter
on any level (other than cosmetic considerations) where any "spatters"
might land. Of coure, a more sophisicated production line could use
something that "spooges" through multiple nozzles, with pinpoint
accuracy. But since most electronic boards are hidden inside some sort
of pretty casing, the typical consumer is never going to see how pretty
it is or isn't. Only "weirdos" like you and me, who open up our
electronic toys to see what makes them tick. :)

Amusement value:
The legend "No user servicable parts inside" that appears on so many
electronic widgets. Guess what, manufacturers... Some of us CAN figure
out how to run a soldering iron, meter, and other electronic servicing
equipment, and can indeed service that "unservicable" device, so your
statement about no user servicable parts is pure baloney. :)

I've always been amused by that one... Dunno why, but it tickles my
funnybone.[/QUOTE]
 
P

phil

Jan 1, 1970
0
The link you gave is not availble.

If you are using a browser you need to type (cut and paste) the link
manually. If you are clicking from OE it should work without that.

b.t.w.
If you look closely, one resistor (on the left) has a thin copper wire
wound around it, what could that be.

n.b.
This circuit is from the maxitronix am-fm radio kit
 
D

Don Bruder

Jan 1, 1970
0
[QUOTE=""phil said:
The link you gave is not availble.

If you are using a browser you need to type (cut and paste) the link
manually. If you are clicking from OE it should work without that.

b.t.w.
If you look closely, one resistor (on the left) has a thin copper wire
wound around it, what could that be.[/QUOTE]

I'm guessing it's actually a small-value coil that just happens to be
wrapped on a resistor-like form. Either that, or it is an actual
resistor, with a small-value coil formed on it. Either way, it's almost
certainly a carefully tuned item that you don't want to mess around with
unless you've got the know-how and tools to retune it to whatever value
it had before you started playing with it. With coils, it doesn't take
much to change their value in a big way - Sometimes, especially in
high-frequency work, adding/subtracting turns, or even moving just one
turn of the coil one wire-width further away from or closer to its
nearest neighboring turn, is sufficient to change the value of the coil
dramatically enough to completely de-tune the circuit and cause the
device it's in to be unusable. (or worse - cause it to continue working,
but on a frequency so different than intended that it seems to be
non-operational by all tests that you can apply)
 
R

Rich Grise

Jan 1, 1970
0
phil said:
My fm tuner circuit is very strange, it has wax all over some parts of
it and inside a coil there is also a spunge which it seems was soaked
in wax.

http://www.geocities.com/myelectronicsrevision/fmtuner.jpg

Any ideas what all this wax is for ?

I don't see any wax at all. Unless that translucent glob on the
left is waxy. It looks just exactly like RTV to me.

I don't konw what the sponge is, but I'm assuming some kind
of spacer.

If you poke that whitish glob with your fingernail, does it leave
a mark? Or is the stuff rubbery? 'cause that board doesn't have
any of that tuner wax on it at all.

(at least not the kind they used last millennium. ;-) )

Cheers!
Rich
 
R

Rich Grise

Jan 1, 1970
0
Not to worry. It's the choke. :)

Cheers!
Rich

Don Bruder said:
[QUOTE=""phil said:
The link you gave is not availble.

If you are using a browser you need to type (cut and paste) the link
manually. If you are clicking from OE it should work without that.

b.t.w.
If you look closely, one resistor (on the left) has a thin copper wire
wound around it, what could that be.

I'm guessing it's actually a small-value coil that just happens to be
wrapped on a resistor-like form. Either that, or it is an actual
resistor, with a small-value coil formed on it. Either way, it's almost
certainly a carefully tuned item that you don't want to mess around with
unless you've got the know-how and tools to retune it to whatever value
it had before you started playing with it. With coils, it doesn't take
much to change their value in a big way - Sometimes, especially in
high-frequency work, adding/subtracting turns, or even moving just one
turn of the coil one wire-width further away from or closer to its
nearest neighboring turn, is sufficient to change the value of the coil
dramatically enough to completely de-tune the circuit and cause the
device it's in to be unusable. (or worse - cause it to continue working,
but on a frequency so different than intended that it seems to be
non-operational by all tests that you can apply)

--
Don Bruder - [email protected] - New Email policy in effect as of Feb. 21, 2004.
I respond to Email as quick as humanly possible. If you Email me and get no
response, see <http://www.sonic.net/~dakidd/main/contact.html> Short
form: I'm trashing EVERYTHING that doesn't contain a password in the[/QUOTE]
subject.
 
M

Michael Black

Jan 1, 1970
0
Rich Grise" ([email protected]) said:
I don't see any wax at all. Unless that translucent glob on the
left is waxy. It looks just exactly like RTV to me.

I don't konw what the sponge is, but I'm assuming some kind
of spacer.

If you poke that whitish glob with your fingernail, does it leave
a mark? Or is the stuff rubbery? 'cause that board doesn't have
any of that tuner wax on it at all.

(at least not the kind they used last millennium. ;-) )

Cheers!
Rich
I've seen sponge like material in air wound coils. I thought or
assumed it was there to keep down microphonics.

RTV probably serves the same purpose as the wax, though who knows if
it affects the coils differently. But the disadvantage is that
it's not nearly as easy to remove if needed. You can always heat
up the wax and it will melt, but getting RTV off usually requires
some scraping, and that scraping may damage the coil you are
trying to get to.

Michael
 
Top