Kenwood TH-F7E User Manual - Page 56

OPERATION NOTICES The transceiver has been designed and engineered to avoid possible hardware glitches. However, you may notice the following symptoms when you operate the transceiver. These symptoms are not malfunctions. OPERATING VOLTAGE As stated in "SPECIFICATIONS" {page 53}, this transceiver operates on a DC voltage from 5.5 V ~ 7.5 V DC (battery terminal) or 12.0 V ~ 16.0 V DC (DC IN jack). If you find that the transceiver cannot be switched ON, or "VOLTAGE ERROR" appears, the supplied power source may be outside of the specified range. In such a case, remove the DC power cable from the transceiver immediately and confirm that the supplied voltage is within the specified range. TUNING IN SSB/ CW MODE The transceiver uses a general purpose IF filter to receive signals in LSB, USB, CW and AM modes. So, when you receive signals in LSB or USB mode, the opposite side band signal is not fully attenuated. At the same time, since the same filter is used for CW reception, you may have difficulties seperating the CW signal from other signals in the crowded band. To best tune in to a SSB signal, follow the instruction below. When you receive signals in USB mode: 1 Turn the Fine Tuning function ON {page 35}. 2 Tune to the target signal while starting at a lower frequency, using the Tuning control. When you receive signals in LSB mode: 1 Turn the Fine Tuning function ON {page 35}. 2 Tune to the target signal while starting at a higher frequency, using the Tuning control. RECEIVING IN AM BAND If you receive a weak signal in AM band, you may notice a high pitched squealing noise in the background. This noise is generated by the internal DC/DC converter and it cannot be removed. RECEIVING SIGNALS IN CITIES When you receive signals in cities, the receiver's entire S-meter may light up without receiving any strong signals. This happens when the RF amplifier in the receiver is overloaded by strong interference signals that are nearby. In this case, turn the Attenuator function ON {page 36} to reduce the interference signal level. You may further have to adjust the volume level while receiving the target signal. 15 TROUBLESHOOTING BEAT AND NOISE When you have the same 2 m, 1.25 m (TH-F6A only), and 70 cm band frequencies for both A and B-band receivers, the Visual Scan may indicate the signals on the bar-graph display even if no signal is monitored on the A-band receiver. This error occurs due to the internal spurious harmonics that are generated by the B-band-receiver. Refer to "INTERNAL BEATS" {below} for the frequencies. You may also hear some noise in the receiving signal in the following cases. • You perform any scan on the other receiver. • You perform the Visual Scan on the B-band receiver. TRANSMISSION If you continuously transmit for more than 3 minutes at high power (5 W), the transceiver becomes warm. If you continue or repeat the transmission before the transceiver cools down, the thermal protector automatically decreases the output power to 0.5 W. "H" also blinks at the same time. If this happens, let the transceiver cool down for a while before transmitting again. INTERNAL BEATS If one of the formulas on the next page is true, the S-meter moves without receiving any signals or you cannot receive any signals. This is inevitable when you use superheterodyne receivers. 51