[R-390] R390A

[Paul Bigelow]

Hello,

The R390a will always take a bit more effort to tune than any receiver with
an encoder or a simple VFO.  With some rebuild work and lubrication, the
R390a can be made a bit easier to tune.  The play noted during tuning could
be the result of improperly set backlash gears or the oldham coupler may be
worn.  If the olham coupler is worn, it may be possible to reduce play by
sandwiching some tough, thin, plastic wrap between the coupler and its
mate, thus filling up the small gaps.  Carefully adjusting the beveled
gears for the Veeder-Root mechanical readout can reduce the play in that
mechanism.

Best regards,

Paul Bigelow
EAC 1967 R-390a/URR Ser. No. 121
Collins 1951 R-392/URR Ser. No. 1254