‰  NOW 10 WPM  ‰  TEXT IS FROM SEPTEMBER 2018 QST  PAGE 82  ‰

CRYSTAL PHASING CONTROL.  OPTIONS INCLUDED A MATCHING SPEAKER, 100/1,000
KHZ CRYSTAL CALIBRATOR, SELECT O JECT, NARROW BAND FREQUENCY MODULATION
NBFM ADAPTER, AND A 6 V POWER SUPPLY SEE FIGURE 1.  THE NBFM ADAPTER WAS A
RESULT OF THE POST WAR GROWTH OF AMATEUR RADIO, ESPECIALLY AM PHONE, WHICH
CAUSED SEVERE CROWDING OF POPULAR FREQUENCIES.  STARTING IN THE LATE 1940S,
‰  END OF 10 WPM TEXT  ‰  QST DE W1AW  ƒ