"Paul P" REMOVE paul @ REMOVE ppinyot . REMOVEcom wrote in message
news:7RWvk.507$sq3.375@trnddc07...
Thank you all for the replies.

I printed out the BAMA schematics and the BAMA
http://bama.edebris.com/manuals/ mods for the NC300. The mods are
numerous.
This chassis has none of them. This can be good or bad depending on the
collectors desires. I would think the factory mods like replacing an
unshielded wire with shielded wire would be totally collector acceptable.
The mod is fixing a design flaw identified by the factory.

I dim bulb (a kin to a variac) tested and opened up the NC300 today to
start
the restoration. I was able to receive station but the dial is way off
and
was unable to clarify SSB. All tubes tested good save one. The mixer is
bad. I cleaned the chassis with Clorox clean up, a tooth brush and a rag.
Now it is nice and shiny.

There is plenty of room under the chasssis for new Electrolytics. Since
this restoration will not have restuffed wax/paper caps I see no harm in
the
underchassis installation. If a collectors want a "museum" level
restoration to show off the underside of the chassis then all new
components
would be hidden inside origonal container, wrappers or what have you.
Reformation of the eletrolytic can is out of the question. There is dried
eletrolyte harded on the vent hole. In my not so hmble opinion - Unless I
have a published life expetancy of the capacitor or the dilectric you are
asking for a recall or burned out components when that capacitor evenually
dries up, shorts or burns up.

There are a lot of paper capacitors underside. They are dipped in some
plastic like coating. But that does not stop the deterioration of the
internal paper. Here again, I think it is best just to "shot gun" them
out.

I have a habit of resistor replacement as well. This is a bit on the edge
of needs to be done or not. My lesson came from an RCA AA5. I replace al
l
caps and aligned. It played for a day and failed. I put it on the bench
and found the out of tolerance resistor. It measued good along with all
the
rest. I repeated these steps three more times before I just decieded to
shot gun the carbon composition resistors. No more problems. If I find
any
out of tolerance reisstors in this chassis I will go ahead and shot gun
these too. The chalenge is not to uses inducive carbon film resistors in
high frequency (relative to the resistor) circuits like the oscillator and
mixer section. I found that in radios that recieve less than 18 mhz all
is
ok. Any thing above that then non inducive resistors must be maintianed.

More later, and thanks again to all whom contributed.

If you want to follow along I will be posting my progress on the web site
at
www.ppinyot.com. It is not there yet.

Paul P.


I hadn't tried Clorox before. I would worry about salts appearing. Do you
flush with distilled water after that?

JB wrote:


I hadn't tried Clorox before. I would worry about salts appearing. Do you
flush with distilled water after that?

Not Clorox bleach, Clorox Cleanup. It is a spray cleaner similar to 409.

If you use Clorox bleach on aluminum, it will etch it and eat it away.

-Chuck

Not Clorox bleach, Clorox Cleanup. It is a spray cleaner similar to 409.

If you use Clorox bleach on aluminum, it will etch it and eat it away.

I worry about those type of cleaners leaving acid or base or solvent
residues, funny smells. There have been radios I ran through the dishwasher
and pulled it out after the rinse and dunked it in hot distilled water,
followed by LP air and bake at 130 for a day. I used to refurb telephones
that way too. Dishwasher is hell on decals though.

"JB" wrote in message
news:7_awk.676$393.564@trnddc05...
Not Clorox bleach, Clorox Cleanup. It is a spray cleaner
similar to 409.

If you use Clorox bleach on aluminum, it will etch it and
eat it away.

I worry about those type of cleaners leaving acid or base
or solvent
residues, funny smells. There have been radios I ran
through the dishwasher
and pulled it out after the rinse and dunked it in hot
distilled water,
followed by LP air and bake at 130 for a day. I used to
refurb telephones
that way too. Dishwasher is hell on decals though.

Years ago, when I worked for Hewlett-Packard, our
method of cleaning equipment was to strip it of anything
which would be hurt by water, meters, dials (in some
equipment) sealed transformers, etc. Then it was washed with
a paint spray gun loaded with warm water and plain
dishwashing detergent. After washing it was rinsed with
plain tap water and then blown out with compressed air. It
was then baked for several days in an electric oven set for
about 130F. One can also use a brush to help during the
spraying part.
The reason for removing sealed transformers was that
our experienc was that they often were not really sealed so
that moisture could get in but couldn't get out again so
there were frequent failures once power was applied. Open
frame transformers got through the process without trouble.
I am also concerned about the long-term effects of
residue from some of the new "magic" cleaners. Plain hand
dishwashing detergent seems to work about as well as
anything and seems relatively safe.


--

--
Richard Knoppow
Los Angeles
WB6KBL