Freeing frozen Tune slugs
 

I'm working on a SB-101 and a couple of the tuning slugs in the
hetrodyne osc are frozen. Whats a good way to free them up? The 20
position is dead and I've swapped out the 20 meter crystal. I suspect
the Plate tuned osc. isn't and would like to tweek it. The 15 meter
slug turns and does a good job of insuring the osc starts or not
depending on how it's tuned.

For those of you are not familiar with this style coil, they are made
of wax? inpregnated paper and are tuned with a threaded ferrite slug
with a hex shaped hole for the tuning wand. In the case of this rig 15
and 20 mneter crystals share a long coil form with seperate coils and
slugs.

The 20 meter slug won't turn. It's stuck to the rather fragile paper
tube all the way to one end of the form..

Thank you any and all advice.

73

Jim

"Jim" wrote in message
oups.com...

I'm working on a SB-101 and a couple of the tuning slugs in the
heterodyne osc are frozen. What's a good way to free them up? The 20
position is dead and I've swapped out the 20 meter crystal. I suspect
the Plate tuned osc. isn't and would like to tweak it. The 15 meter
slug turns and does a good job of insuring the osc starts or not
depending on how it's tuned.

For those of you are not familiar with this style coil, they are made
of wax? impregnated paper and are tuned with a threaded ferrite slug
with a hex shaped hole for the tuning wand. In the case of this rig 15
and 20 meter crystals share a long coil form with separate coils and
slugs.

The 20 meter slug won't turn. It's stuck to the rather fragile paper
tube all the way to one end of the form..

Thank you any and all advice.

73, Jim


I assume that you can not turn the slug up or down?

In order not to break the ferrite slug - I would probably use a heat gun to
WARM UP the impregnated paper form - BUT not so much as to damage it.
and then try again -- not trying to break the slug

w9gb

Jim wrote:
I'm working on a SB-101 and a couple of the tuning slugs in the
hetrodyne osc are frozen. Whats a good way to free them up? The 20
position is dead and I've swapped out the 20 meter crystal. I suspect
the Plate tuned osc. isn't and would like to tweek it. The 15 meter
slug turns and does a good job of insuring the osc starts or not
depending on how it's tuned.


In my experience, frozen slugs are very often not actually frozen, but rather
split in half lengthwise. When you try and turn the slug, the diddle stick
cams the halfs of the slug apart, and makes it impossible to turn. The worse
slugs for this problem are the square, or triangular hole type. The hex hole
slugs will break this way too, especially if you use a steel allen key to turn
them.

One way to free slugs that have this problem is to stabilize them by gluing
a round toothpick in the hex hole. A drop of yellow carpenters glue will
work nicely. Be sure to be frugal with the glue, you don't want it to
touch the form in any way.

-Chuck