56
Receive
§ HI RFI warning, preamp turns off, or RX icon turns on: The KX2 protects itself from high received signal
levels. First the preamp is turned off, if it was on. The second step taken by the KX2, if necessary, is to turn on
the RF attenuator. The receive overload icon (RX), near the ANT icon, will turn on. Once signals return to a
safe level for 5 seconds, the attenuator will be turned back off. Also see COR (next item).
§ Carrier-operated relay activated (a relay is heard, and the RX icon turns on): The carrier-operated-relay
(COR) may be activated due to the signal from a nearby transmitter. This is usually due to close proximity
between your antenna and the other station’s antenna. The COR is actually the relay for the present low-pass
filter. When the relay opens, signals will drop by 40 to 60 dB, protecting the KX2. The relay will close again
shortly after the signal drops. If the COR is being repeatedly activated, try moving the antennas farther apart.
You can also increase the COR threshold, at your discretion; see MENU:COR LVL.
§ HI CUR warning: May indicate that speaker volume is too high; gain is reduced by the KX2 in this case.
§ No received signal: Check (1) antenna connectors; (2) RF gain too low (set RF gain menu entry fully
clockwise, to –0 dB); (3) bandwidth too narrow (tap FIL and rotate AF GAIN/MON to widen the passband);
(4) MENU:REF CAL parameter not adjusted properly.
§ Signals very weak below 3 MHz: The KX2 is designed primarily for use on 80-10 meters (3 to 30 MHz).
Receive capability extends down to 500 kHz, but as shown in the Specifications section, signals will be
progressively attenuated below 3 MHz due to high-pass filtering in the T/R switch. (This filtering is intended to
protect the T/R switch PIN diodes.) Attenuation will be approximately 15-20 dB in the 160-meter band, and
much greater at the low end of the AM broadcast band. Sensitivity should still be adequate for reception of
strong AM broadcast stations, useful in an emergency. Also see next item regarding mixer images in this range.
§ Signals in the 500 kHz-3 MHz range appear to be off-frequency: These may be mixer images of signals
higher up in frequency. They appear because the KX2 does not provide filtering below 3 MHz (see above).
Generally, if an AM broadcast signal in the 550-1700 kHz range can be tuned in at an exact multiple of 10 kHz
in LSB or USB mode, then it is a legitimate signal. Those tuning in at non-multiples of 10 kHz are likely to be
images.
§ Received signal level too low: (1) check headphone and speaker plugs and cables; (2) make sure that
MENU:RX EQ has not been set for large cuts; (3) verify that MENU:REF CAL is properly adjusted; (4) make
sure MENU:RF GAIN is set to -0 dB.
§ Spurious signals (“birdies”): All receivers exhibit some birdies. Most will be inaudible with an antenna
connected. In the KX2, there may be significant birdies or harmonics of birdies at the following frequencies
due to internal signal sources: 16000 and 18432 +/- 5 kHz (MCU and DSP clock frequencies), 500-900 kHz
To Next Page
Loading...
