Icom IC-7800 Instruction Manual - Page 176

MAINTENANCE 13 I Frequency calibration (approximate) A very accurate frequency counter is required to calibrate the frequency of the transceiver. However, a rough check may be performed by receiving radio station WWV, WWVH, or other standard frequency signals. CAUTION: The IC-7800 has been thoroughly adjusted and tested at the factory before being shipped. You should not have to re-calibrate it. [F-7•SET] [F-1•Y] [F-2•ACC]/[F-2•Z] [EXIT/SET] Main dial [F-5•OTHERS] • Calibration marker item • REF Adjust item q Push [SSB] to select USB mode. w Push [PBT CLEAR] for 1 sec. to clear the PBT set- ting and make sure that the RIT/∂TX function is not activated. e Set the frequency to the standard frequency station minus 1 kHz. • When receiving WWV or WWVH (at 15.00000 MHz) as a standard frequency, set the operating frequency for 14.99900 MHz. • Other standard frequencies can be used. r Push [EXIT/SET] several times to close a multi- function screen, if necessary. t Push [F-7•SET] to select set mode menu screen. y Push [F-5•OTHERS] to enter miscellaneous (oth- ers) set mode. u Push [F-1•Y] several times to select the "Calibra- tion Marker" item. i Rotate the main dial clockwise to turn the calibra- tion marker ON. o Push [EXIT/SET] once to return to set mode menu screen. !0 Push [F-2•ACC] to enter accessory set mode. !1 Push [F-2•Z] several times to select the "REF Ad- just" item. !2 Rotate the main dial to adjust for a zero beat with the received standard signal as shown at left. • Zero beat means that two signals are exactly the same frequency, resulting in a single tone being emitted. !3 Turn the calibration marker OFF in miscellaneous (others) set mode. !4 Push [EXIT/SET] twice to exit set mode. 13-5