Kenwood TS-990S Operation Manual - Page 281

TROUBLESHOOTING 18 NOTICE CONCERNING INTERNAL BEAT On some particular frequencies along the amateur band an internal beat may occur due to the frequency configuration. This is not a failure. Following are examples of the internal beat. (Frequency may vary depending on the operating mode.) In the following examples, "Main" represents the displayed frequency of the main band, and "Sub" represents the displayed frequency of the sub band. In some examples the selected transmitting band is also a factor in generating an internal beat. INTERNAL BEAT OCCURRED IN THE MAIN BAND • In combination of the main band range from 18.068 MHz to 18.150 MHz and the sub band range from 14.104 MHz to 14.350 MHz, and the transceiver transmits on the sub band. Example: Main 18.100 MHz and Sub 14.200.28 MHz • In combination of the main band range from 28.199 MHz to 28.765 MHz and the sub band range from 28.000 MHz to 29.700 MHz. Example: Main 28.200 MHz and Sub 28.003.40 MHz • In combination of the main band range from 50.753 MHz to 51.453 MHz and the sub band range from 14.000 MHz to 14.350 MHz. Example: Main 50.760 MHz and Sub 14.004.97 MHz • In combination of the sub band range from 21.448 MHz to 21.450 MHz and the main band range from 14.000 MHz to 14.006 MHz, and the transceiver transmits on the main band. Example: Sub 21.450 MHz and Main 14.005.52 MHz • In combination of the sub band range from 29.248 MHz to 29.698 MHz and the main band range from 21.000 MHz to 21.450 MHz. Example: Sub 29.250 MHz and Main 21.003.00 MHz • In combination of the sub band range from 50.246 MHz to 51.246 MHz and the main band range from 1.800 MHz to 2.000 MHz. Example: Sub 50.250 MHz and Main 1.802.21 MHz • In combination of the sub band range from 52.634 MHz to 52.834 MHz and the main band range from 18.068 MHz to 18.168 MHz. Example: Sub 52.640 MHz and Main 18.071.10 MHz OTHER COMBINATIONS The internal beat occurs while the transceiver receives, using the sub band, on the frequency which has the first IF frequency of 73.095 MHz. (Depending on the frequency of the sub band, the internal beat may also occur on the sub band.) Example: • Sub 50.010 MHz and Main 28.298.28 MHz • In combination of the main band range from 52.028 MHz to 53.361 MHz and the sub band range from 50.000 MHz to 54.000 MHz. Example: Main 52.030 MHz and Sub 50.006.75 MHz INTERNAL BEAT OCCURRED IN THE SUB BAND • In combination of the sub band range from 3.769 MHz to 3.839 MHz and the main band range from 14.000 MHz to 14.350 MHz, and the transceiver transmits on the main band. Example: Sub 3.775 MHz and Main 14.014.57 MHz • In combination of the sub band range from 10.100 MHz to 10.150 MHz and the main band range from 1.852 MHz to 1.902 MHz. Example: Sub 10.110 MHz and Main 1.862.00 MHz • In combination of the sub band range from 7.000 MHz to 7.174 MHz and the main band range from 14.002 MHz to 14.350 MHz, and the transceiver transmits on the main band. Example: Sub 7.050 MHz and Main 14.095.90 MHz SPURIOUS SIGNAL ON THE BANDSCOPE (WATERFALL) A signal which has no correlation to the received signal may appear on the bandscope (waterfall). This may occur due to the frequency selection and is not a failure. The spurious signal display may be reduced by adjusting the attenuator and the reference level of the bandscope. Example: • The frequency which has ±24 kHz separation from the receive frequency • The frequency which has ±150 kHz separation from the receive frequency • (The spurious signal may differ depending on the receiving band or the operating mode.) • While the transceiver is receiving an internal beat • In combination of the sub band range from 14.000 MHz to 14.350 MHz and the main band range from 28.500 MHz to 28.850 MHz. Example: Sub 14.010 MHz and Main 28.510.60 MHz • In combination of the sub band range from 21.000 MHz to 21.450 MHz and the main band range from 51.996 MHz to 52.446 MHz. Example: Sub 21.010 MHz and Main 52.006.51 MHz Contents Index 18-3