[JMS] More of several comments on the National SW-54

[Sherrill Watkins]

Friends of the James Millen Society:  I really do appreciate Jim Hanlon's
observations about restoring old radios. Perhaps I should have been clearer
but note that I referred to  PAPER capacitors. The SW-54 has numerous disc
ceramic type and these should be ok as the ceramic does not normally
deteriorate with age. However, I have found some that have; I think they
absorbed moisture?  My SW-54 had both the paper wax dipped type and black
beauties installed and both of these are known sources of major trouble.
However, I would also like to point out that Jim and I have a slightly
different philosophy to approach this. Jim seems to be a real "museum
curator" and wants as much of the original electronics to remain undisturbed.
In the long run, his approach is probably the best from an historical
perspective.  However, my approach is that I want my radios to WORK when I
turn them on; with no unpleasant surprises, i.e. smoke. There is really no
right or wrong approach here; it depends on one's perspective and what your
object is. Also, it has been my suspection that a lot of these radios,
especially the one's that were made to sell at a low price, i.e. the National
SW-54 is a perfect example, may have had lower quality resistors and other
components installed than those installed in the high end radios. This is why
I recommend replacing all the resistors. Also, I suspect that lower wattage
resistors may have been used where higher wattage one's should have been
installed. Again, to meet a low selling price for the radio. You may find
that most of the resistors are within specification and you may wish to leave
them undisturbed. The final decision will be the person restoring the radio
and depends on one's perspective. My comments are that all PAPER capacitors,
wax dip or "black beauty" and others should be replaced. Also, any component
that shows that it has overheated should be replaced. If you do not, you
should expect future trouble. I have restored about a half dozen old radios
and all but one of the old electrolytic filter capacitors were defective.
Only one was not, but if failed about a year after I brought the radio back
to life. I removed the internal components of the can, installed new
capacitors inside the old can and mounted the old capacitor in its original
location on the chassis to keep the original look of the radio. 

-73- Sherrill, k4own