Atlas 210x, Installation, Operation And Maintenance Manual

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The 0 to 500 dial scale is used on all bands. The 0 to 500 dial scale reads directly on the 7, 14, and 21 MHz bands.
On the 3.5 MHz band, the dial scale reading is additive. The 10 meter band is calibrated directly above the dial
scale and reads from 28.4 to 29.4 MHz. The increment markings on the tuning knob skirt are 1 kHz apart on the
lower bands, and 2 kHz apart on 10 meters.
3-9. BAND SELECTOR AND TUNING DIAL, MODEL 215x
The number on the band selector reads in MegaHertz, the same as on Model 210x, except that it has the 1.8 MHz
band instead of the 28.4 MHz.
The 0 to 500 scale reads directly in KiloHertz on the 7, 14, and 21 MHz bands. On the 3.5 MHz bands, the dial
scale is additive.
3-10. DIAL SET
This panel control is for adjusting dial calibration to exact reading at a 100 KHz marking
3-11. CARRIER BALANCE
A trim pot is located on the PC-100C plug-in board on the right side of the transceiver. Next to the trim pot is a
capacity trimmer which is the phase control. These trimmers should be adjusted for minimum carrier on the lowest
frequency band. Connect a dummy load to the transceiver, and measure output voltage in TRANS mode with MIC.
GAIN at minimum. It should null down to a level of 0.10 to 0.15 volts RMS. Other bands will give a false reading
due to oscillator feedthrough which is not suppressed as much as the carrier.
3-12. S-METERZERO
This is a trim pot located on the PC-200C plug-in board. The PC-200C PC board is located under the dial drum. It
can be reached with a phillips screwdriver from the top, just behind the dial light switch. Disconnect the antenna
and adjust the trim pot for meter 0.
3-13. CRYSTAL CALIBRATOR. The 100 kHz calibrator should be checked every 6 months or so against a
frequency standard such as WWV. Aging will cause it to gradually change frequency, especially during the first
few months. The calibrator is mounted on the back side of the aluminum partition, under the shield, behind the dial
drum. A capacitor trimmer in the upper left hand comer is for frequency adjustment. A test lead may be run from
terminal 1 of PC-100C to the antenna terminal on a general coverage receiver which is tuned to one of the WWV
frequencies: 2.5, 5,10 or 15 MHz. Adjust the trimmer for zero beat when WWV interrupts their tone modulation.
3-14. PROPER TUNING OF SINGLE SIDEBAND SIGNALS
Precise tuning of a single sideband signal is very important. Try to tune exactly to the frequency where the voice
sounds normal. Avoid the habit of tuning so the voice is pitched higher than normal, and sounds like Donald Duck.
This is an unfortunate habit practiced by many operators. If you tune for an unnatural high pitch you will then be
off frequency when you transmit. Chances are that the other station will then shift to your frequency while you are
talking, and gradually you will move up or down the band. Sooner of later one of you will accuse the other of
drifting . . . So, take the extra care to tune for a natural sounding voice, and you will then be enjoying the very best
quality in voice communications.
315. VOICE TRANSMISSION
Normal operation is with the Function Switch in the REC. position. Pressing the Mic. button switches the
transceiver into transmit mode. Or, if the VOX accessory is installed in the 220-CS console, speaking into the Mic.
will switch the rig into transmit mode. A TRANS. position is also provided on the Function Switch for locking in
the transmit mode, or in case the Mic. does not have a press-to-talk switch.
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