TelePost LP-100A, Руководство по эксплуатации

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Calibration
Included for reference
… LP-100A is factory calibrated with NIST traceable standards
Accessing the Calibration mode is similar to accessing Setup mode, except that you hold the Mode button until you see the initial
Calibration screen. Exiting Calibration Mode is done by holding the Mode button for about 1 second until you see the main operating
screen. Wherever CH1 is shown, there is also a similar screen for CH2 that is displayed when the CH2 coupler is active.
Calibration Mode title screen. This place holder makes it difficult to accidentally change a setting when
entering Calibration Mode. It acts as a buffer.
Starting with serial #400, this menu was changed to a serial number selection, and covers any hardware
change between versions instead of just cables as before. In the case of the 5
th
run, it covers the change in
response of a slightly different model power combiner. For the LP-100A, it will be at least #701.
This screen facilitates calibration of the 2
nd
coupler when Dual Coupler Display Option is installed. It copies
the data from the CH1 coupler, which will populate the CH2 CAL Table with values close to those which will
be required. You will be asked to confirm this action by pressing the UP button.
This screen allows you to enter the actual impedance of your dummy load on a per band basis. This will
result in a more accurate calibration if your dummy load is other than exactly 50.0 ohms, or changes with
frequency.
This screen allows you to zero the phase detector on a per band basis, correcting for slight variations in the
coupler on the higher bands.
This adjustment is used to calibrate the slope of the gain detector. It is accomplished by transmitting into a
25 ohm load and setting the Trim for a read
ing of 25.0 (or whatever the actual load resistance is if it’s not
exactly 25.0).
This adjustment is used to calibrate the slope of the phase detector. It is simply done by inserting a line with
known delay into the Current input of the LP-100A, and transmitting into a high quality 50 ohm dummy load.
The controls are then adjusted so that the display correctly shows the line delay. If coax of known velocity
factor is used, the line length in degrees can be simply calculated.
Allows adjustment of the accuracy of the op-amp detector and ADC to provide correct conversion values at
low power levels. The screen shows the output voltage of the detector, and the Trim level is set by
adjusting for zero voltage with no RF power applied.
This screen is used to match the readings of the low power and high power ADC inputs. It is done at a
power level below 380W, which is the point at which the low power input reaches maximum. Its purpose is
to allow compensating for any error in the 1% precision divider parts used in the high power input.
Adjusts overall power accuracy of the LP-100A. This adjustment affects all frequencies equally, and is
made by comparing the LP-100A power reading with an accurate reference. Acceptable reference
measurement devices can be inexpensively made, and will be described later.
Same as above, but adjusts the displayed power reading on a per band basis. The built-in frequency
counter detects the band you’re on, and stores the CAL constant for each band automatically for 11 bands
from 160m through 6m. The counter works from 50 mW to 3000W.
This screen is used to adjust the frequency counter to compensate for differences in the reference ceramic
resonator used as a time base in the LP-100A. Counter accuracy is 10kHz, which is far more than needed
to calculate interpolated trim settings between bands for power and impedance. Nominal trim setting is
1605.