[R-390] Quick and accurate calibrator adjustment

[Charles A Taylor, WD4INP]

There's a quicker adjustment method to put the 100 kHz calibrator on 
frequency than what is presented in the manual.

While observing the antenna disable relay K104 from the right side while 
looking over the R-390A front panel:

1. Switch the set FUNCTION switch from MGC to CAL.

2. Observe that the K104 armature operates upward.

3. Using an insulated alignment tool, wedge the armature open (down).

4. Tune WWV/WWVH/JJY on as high a frequency as you can.

5. Zero-beat the calibrator against one of the above stations by adjusting 
CAL ADJ trimmer C310.

NOTE: in lieu of the above stations, it's fairly safe to calibrate against 
a US, Canadian, or European station
operating on a multiple of 100 kHz.

Also, you're radiating a weak signal while doing the above. It's not likely 
to cause any significant interference,
but keep the procedure short.

        -----
Charles A Taylor, WD4INP
Greenville, North Carolina