Calibration Procedures
Frequency Calibration
The P3 requires no calibration for normal panadapter operation. However if additional frequency accuracy is desired, you can perform the following calibration procedure.
Turn the transceiver and P3 on and allow them to warm up for 30 minutes, minimum, before performing the calibration.
•
If the transceiver has a calibration procedure to correct its frequency errors, perform that procedure first.
•
Using a well-calibrated signal generator or an on-the air carrier signal of known frequency, tune in the signal on the transceiver. An A.M. broadcast station can serve as a suitable test signal.
•
Adjust the transceiver frequency to the known frequency of the test signal. Depending upon the modulation mode of the transceiver, the signal may not be audible.
•
Set the P3 to tracking mode via
MENU:FixTrack, set the span to minimum, and adjust the reference level and scale so you can easily see the signal.
•
Hold
C E N T E R
twice to remove any center frequency offset that may have been introduced.
•
Select
MENU:Ref Cal
, tap the
SELECT
knob, and adjust the frequency calibration until the carrier is centered horizontally on the display. If the required correction is more than a few hundred units, it may be that the I.F. frequency is set incorrectly. That can be adjusted via MENU:
Xcvr Def
.
Amplitude Calibration
The P3 comes with a default amplitude calibration that works well with a K3 transceiver. Note: If your
K3 was manufactured before September 2009, it must have the “I.F. Output Buffer Gain
Modification” for the default value to be accurate
(see the note at the top of page 4).
If you have an older K3 without the modification or you are using another type of transceiver, or if
39 you’d simply like to optimize the calibration, you can perform the following calibration procedure.
You will need a signal generator with a calibrated output level. The recommended frequency is 7040 kHz with an output level of 50 microvolts (-73 dBm). The Elecraft XG2 signal generator will provide the recommended output and frequency.
Other power levels and frequencies within range of your transceiver may be used. You’ll need to make suitable adjustments to the frequencies and levels given in the following procedure.
•
Connect the P3 IF IN to the transceiver’s i.f. output.
•
If using a K3, connect the RS232 cable between the K3 and P3, turn the preamplifier OFF, the attenuator ON and be sure the sub receiver is not enabled.
•
Connect the signal generator to the transceiver antenna input. If using a K3 with the KXV3 option, it is best to use the
RX ANT IN connector to eliminate the possibility of damaging your signal generator if you accidentally put the K3 in transmit. If you use the main antenna connector and have the KAT3 option installed, put it in bypass by holding
AT U
until BYPASS appears on the LCD display.
•
Set the signal generator for 7040 kHz at a signal level of 50µV (-73 dBm).
•
Put the P3 in tracking mode via
MENU:FixTrack, set the span to 100 kHz , and tune the transceiver to approximately
7015 kHz so the signal is centered on the right half of the display.
•
Set the P3 Scale to maximum expansion
(10 dB) and adjust the Ref Lvl to about -78 dBm in order to place the signal peak about half way up the screen. You may notice a slight variation in the peak signal level with small adjustments in the transceiver frequency as the signal moves from pixel to pixel on the screen. Adjust the frequency for maximum reading.
•
Select
MENU:Lvl Cal
, tap the
SELECT
knob, and adjust the knob to place the signal peak at -73 dBm on the display.
Note: the K3’s RX ANT input has about 1 dB less loss than the ANT connector, so you may want to set the signal level at -72 dBm when using that input.
Amplitude Calibration for
Transverters
You can calibrate a receiving or transmitting converter, either the K3’s internal K144XV or an external device connected to the K3.
If you plan to do the above calibration on an HF frequency, do that first since that calibration will affect the transverter calibration.
•
Set up the P3, the signal generator, the transverter and the K3 in the manner described above to obtain a signal in the center of the right-hand side of the display and with its peak centered vertically.
•
Select
MENU:XV Gain
, tap the
SELECT
knob, and adjust the knob to select the desired transverter band: 1-9. (You can enter separate calibration values for each transverter band by repeating this procedure for each band.)
•
Tap
the
SELECT
knob again, and adjust the knob to place the signal peak at the level corresponding to the output of your signal generator.
Transmit Monitor (Tx Mon)
Calibration
The transmit monitor sensor is factory calibrated with sufficient accuracy for most applications. If you have a well-calibrated power meter and want to have your P3 match its readings, you can adjust the
P3 calibration as follows. A separate calibration value is stored for each of the three sensor types, so if you have more than one sensor adjusting the calibration of one will not affect the calibration of the others.
•
Connect a high-quality dummy load to the sensor LOAD connector.
•
In TXMonMenu select SensorCal and tap the knob to activate the adjustment.
•
Transmit a CW signal through the sensor and adjust the P3 SELECT knob to match the power indicated on your external meter on the P3 PEP display.
•
Exit the menu to store the new calibration value in memory.
40
