24
Operation cont’d
Connecting Cable.
All LP-100s after serial #100 are supplied with RG-58U connecting cables between the coupler and main chassis.
Earlier versions used RG-174U. This screen allows selection of the appropriate cable. It selects the proper correction table for the cable
loss vs. frequency. The difference is only a couple percent at 6m, but eliminates recalibration when changing cables.
Edit Gain/Phase Trims
. Allows editing of the Gain/Phase Zero adjustments, which are normally set automatically. The Dn button scrolls
from 0-255 with wraparound for gain trim, and the Up button does the same for phase trim.
Range.
Allows setting of maximum bargraph scale values for all three autoranging scales. The Dn button selects Low, Mid or High
range, and the Up button allows scrolling through the various max power options. The displayed range includes 0.4dB overshoot
(~10%) above the indicated value. Note: These ranges do not affect the numerical readout, which has no limits. Defaults are 15W,
100W, and 1500W.
Bargraph Max Range.
Sets the maximum excursion of the bargraph for the three automatically selected ranges. The choices are…
Low – 5, 10, 15, 20, 25W
Mid – 50, 75, 100, 125, 150, 175, 200, 225, 250W
High – 500, 750, 1000, 1250, 1500, 1750, 2000, 2250, 2500W
Defaults are 15W, 100W and 1500W.
Each range includes 0.4dB overage, so that the 100W selection would extend to 110W, for example.
Note: These settings do not affect
the numerical readout, which has no limits of any kind.
The center button selects the range, and the right button sets the power level, with wraparound to the beginning value.
Fast Bargraph Range
. Sets the width of the bargraph in Fast mode from 2dB to 10dB. This allows tailoring of the bargraph resolution for
amplifier tuning to simulate an analog meter. The response is still logarithmic to minimize jitter, and be more like the typical square law
analog meter response. The default is 9dB.
Averaging Samples
. Sets the number of samples for power averaging, adjustable from 2 to 32 samples. Default is 8 samples.
Peak Hold Time
. Sets the hold time in Slow (peak) mode. Adjustable from 0.25 to 5 seconds. The shortest time can be used for
amplifier tuning, especially with a pulser. The default setting is 2 seconds for normal SSB or CW operation.
Alarm User Setting
. Allows setting an alarm threshold other than the preset choices. Any setting from 1.0 to 5.0 is permissible.
After entering the Setup mode, these various screens can be accessed by cycling through them using the Mode button. In Setup mode,
the Alarm button becomes a Dn (or Save or Select) button and the Fast/Slow button becomes Up (or Reset). You can adjust the value
of the CAL constant for each screen using these buttons. The value of the CAL constant is stored in non-volatile memory. You may also
want to write down your values on the page provided at the end of this manual.
Screen Saver
The screen saver dims the screen after approx. 30 sec of inactivity, and marches your call sign across the screen after approx. 2 min.
of inactivity. This is done to extend the life of the PLED display. Check the software section of the manual for instructions on
programming your callsign into the LP-100. Application of RF power will return the LP-100 to normal display. Alternatively, pressing the
Fast/Slow button will do the same thing if not in Calibration Mode.
Note: Make sure you are in the desired Fast/Slow mode after using
the button to cancel the screen saver.
Normal Operation
In normal operation, the LP-100 is left in the Normal mode. For SSB or CW operation, you should use the Slow (or peak-hold) Power
mode. This mode will show peak power and SWR and hold them for the preset hold time unless a higher peak is detected, at which
time the timer resets. Do not use this mode for steady-state power or SWR measurements, as it will be affected by momentary power
fluctuations that many modern rigs have.
The peak power reading can be as much as 30% higher than steady-state power readings taken in the Fast mode. This is because of
the ability of the transmitter or amplifier to deliver short bursts of higher power due mainly to power supply regulation issues. This is
especially true of older amplifiers with unregulated power supplies, but also is affected by the ALC timing characteristics of modern rigs
in both CW and SSB. The peak detector in the LP-100 is very fast, and will grab even the smallest peak.
Содержание LP-100
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