[Hallicrafters] SX-28 RF alignment

[Mike Everette]

Julian,

I think Al's advice is very good.  Maybe something
miswired; perhaps a bypass cap that ended up connected
to something other than what it was supposed to
bypass.

But here's another possibility:  bad ground
connection.  I saw this a couple of weeks ago with an
HA-1 TO Keyer.  One of the tubes would not light; yet
there appeared to be filament voltage on the socket. 
Indeed there was; but, the ground connection to the
filament of that tube was made through a terminal
strip attached to the chassis with a rivet.  The rivet
itself, or the rivet hole, or both, had corrosion.  I
was able to clean it out with penetrating oil, then
washed the oil out with aerosol equipment degreaser. 
It worked; but in this non-critical circuit, I
provided insurance by routing a wire from another
ground point to that terminal.

73

Mike
WA4DLF




 
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