DRAKE R-4A Spécifications télécharger pdf (Page 36)

100 KC Calibrator Alignment

Attach the antenna to the R-4A and tune in WWV at the frequency

most reliable in your area.

For crystal selection see the chart

on page 18.

Set the Function switch to CAL. (A shorted plug must be inserted

in the Mute jack).

Adjust the calibrator adjust trimmer (C119) for zero beat with the

unmodulated WWV carrier.

Note that Cl19 is located under the chassis on the component board

on which the 100 KC crystal is mounted, and is accessible through a

hole if bottom cover is in place.

V.F.O. Adjustment

The permeability tuned VFO was carefully adjusted at the factory and

should require no further alignment.

If the VFO does not appear to track from one end of the range to the

other, it should be returned to our plant for alignment. Maximum

calibration error is 1 KC when calibrated at nearest 100 KC point.

If you notice the same error from one end of the band to the other and

you cannot correct it with the movable dial index, the main dial may

be slipped on its shaft enough to bring the calibration back into range.

Notch Filter Aliqnment

Tune in the crystal calibrator signal at any frequency for zero beat.

Set the Notch control to the center of its range.

3. Adjust the slug in T8 for minimum S-Meter reading.

Pas sband Tuner Alignment

Turn

Passband

tuning knob through its rotation and observe the

travel of the four slugs visible from the rear of the tuner.

2. When these slugs are nearest the rear of the receiver, the Pass-

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DRAKE R-4A Spécifications Page 36