On alignment. In my 50 plus years of trouble shooting and fixing
experience, never ONCE has alignment fixed an ailing radio.
Sure, alignment has been needed to touch up a radio after a part was
replaced. Most alignment was designed in because coils were not made to
the precision needed for proper performance, or the gain of active
devices wasn't controlled in manufacture, or most often the input and
output C of a vacuum tube varied a few pf and at RF more than IF the
differences from one tube to the next (more serious when changing
brands) changed the resonant frequency significantly. That was much
worse when the tuned circuit C was under 100 pf.
Yes, tuned circuits do drift, faster with lots of heat and cold
temperature cycles. But a radio down in performance may have a failing
part like an IC or a transistor or more likely miniature aluminum
electrolytics with high series resistance (e.g. dried out). Crystals
drift too but on a scale hard to measure with the ordinary ham rig.
Circuits about crystals drift more than the crystals do.
Point is, when a radio's performance is down, find and fix the ailing
part before you go in a "align" it trying to compensate for the failed
part and then adding the need for a proper alignment after you do fix
the failed part.
73, Jerry, K0CQ
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