[R-390] Some practicalities on alignment of the R-390A/URR

[WD4INP]

Just got an Imperial s/n 1923. No reason to doubt that at least the mainframe is Imperial, although some of
subassemblies are other than Imperial. Appears to be Army and used up to around 1970 because it has 
a National Stock Number vice a Federal Stock Number. FSNs were converted to NSNs around that time 
frame. 

More about this fascinating aspect for anyone who writes me via the reflector. I could run on to eternity
about some of these aspects, but somewhere either I or someone will cry, "enough!" Alert me of your
query directly, as I WILL miss your query if via the reflector. The reflector is full of quotes, and quotes
of quotes, and quotes of quotes of quotes by you LOUTS (85% of you) that won't take the trouble to
delete the extraneous material. Some 75% of the material on the reflector is extraneous! Try vewwy,
vewwy hard to undewstand these wittle wowds.

Back to the matter at hand:

To save you some trouble, when you align R-F subassemblies that are energized with plate voltage,
be careful. Use an insulated screwdriver lest thou meet thy creator prematurely. It is not of great
consequence if you briefly short an energized trimmer to the slug rack. Unless a resistor has already
been burnt to about 95% of opening up, it will take the abuse BRIEFLY. 

So don't call 9-1-1 and have a heart attack (in either order) if you do so inadvertently. 

Keeping in mind that the R-F subassembly is troublesome to remove and replace.

Chaz

Charles A Taylor, WD4INP
   Grifton, North Carolina