[R-390] How to free stuck IF slugs?

[Flowertime01 at wmconnect.com]

Good Morning Jim, James Cottle,

Sounds as if the slug is already cracked. Try using a small pick, etc. and
clean the top of the slug. You might now be able to see or feel crack/cracks
in the slug. If this is the case; time to shop for a new/used IF
transformer.

Others have been lucky and used an alignment tool with a dab of super glue
and the slug has moved/peaked after the glue dried and pulled the slug away
from the ID of the coil.

I had this same issue on T101, don't have the manual in front of me, could
be another transformer. Anyway, someone on the forum listed a transformer
and some RF slugs for sale a couple months after finding the cracked slug.
Just what dad needed!

Another option if a spare transformer is available/found; a root canal. Use
progressively larger drill bits drilling out the stuck slug and replacing it
with a slug from the other transformer.

Good luck, it can be fixed.

Regards,
Craig
-----------------------------------------------
Jim,

Before you put to much effort into tweaking a core, make sure it needs to be 
tweaked. If it ain't broke don't try en fix it. There is a good chance the 
core is peaked from a previous alignment.

Put 150 uv at 455 into the IF deck and determine if you can get - 7 volts on 
the diode load. With 30% modulation, you should get 1/2 watt out of the local 
audio across a 1 watt 600 (580) ohm resistor. Between turning the modulation 
on and off you should get 30 DB difference in the signal plus noise to noise. 
This procedure is in the TM and the Y2K manual for setting up the IF deck. 
Changing tubes will get you more than adjusting the transformers. Back in 68 - 75 
doing two a day we almost never tried to adjust the transformers.  I have done 
the transformer adjustments and yes it will get you a little or lot more 
output.

If you do need a transformer or slug, list the one you need here. Fellows 
have spare parts decks and may be able to help you.

Have no fear. If you break it, it can be replaced. You can do it your self. 
Or you can ask here if someone local to you can do it.

Pull the cover off the transformer and do the inspections as Craig detailed 
above. If the problem is in a bottom slug, you can run the top slug out of the 
coil form and look at the bottom slug. Some times the bottom slug can be run 
out of the bottom of the coil form through the chassis to allow you to look at 
the bottom end of a top slug.

You can get the hair dryer and warm the coil core up to melt some of the wax. 
While it is warm you can run the slug up and down to "recut" the threads 
through the wax. As it cools keep the slug moving. If it gets tight again stop. 
Try to warm the core up and set the slug while the wax is hot. 

Some have tried a small diameter long tip on a low wattage solder iron to 
warm a slug.

Some have tried to warm the whole deck in the oven at 200 degrees. This 
leaves the whole deck looking real shiney. Some like to put the deck in the dish 
washer before it goes in the oven. You see folks paying big bucks on E-pay for 
these cosmetic operations. Along the way, the heat will let some stuck parts 
come free. The process is mostly non invasive, below the melting point of 
solder. Considering what the Julian Creek Receivers were exposed to, a trip in the 
dish washer and oven is gentle cleaning.

Thinking of the number of decks I dunked into the teletype and typewriter 
(mill) cleaning tank, running a deck in the dish washer is fairly benign.

Do not try a bunch of solvents. The boat anchor folks have treads about all 
kinds of things and ways to dissolve coil forms.

If you have to drill your slug out and the replacement slug does not hang in 
for adjustment you have two options. One is some bees wax melted into the coil 
form. Second is a small chunk of rubber band. The band from an old golf ball 
works. A rubber band can be sliced down for a small square strand that will 
also work.

Someone talked about having a nice white power used by magicians to dust card 
decks and make them very slippery. Motorola use to provide the stuff to their 
technicians for use on slugs and in coil forms. The stuff is finer than talc 
and stays slippery when moist. The stuff a magicians power was cited as you 
are likely to find it in a magic shop. Magic shops being more prevalent than 
electronic parts shops these days.

Roger KC6TRU