11
Detailed Operation
Cont’d
Bargraph Decay
. Allows setting the decay time of the power bargraph. The default setting is Fast, and provides a decay of less than
one second. The longest setting is Slow, and provides about a 3 second decay. In all cases, the attack is instantaneous.
Coupler Type.
This screen is used to select different maximum power values to be used with custom high power couplers. Use Dn/Up
to cycle through the choices. The default is LPC1 (the standard coupler
). Current choices are “LPC1 3KW 1.8-54MHz, “LPC2 5KW 1.8-
30MHz”, “LPC3 250W 0.1 - 20MHz”, ”, “LPC4 5KW 1.8-54MHz”, “LPC5 10KW 1.8-30MHz” and “LPC6 1KW 0.10 to 10MHz”. Use
Dn/Up to cycle through choices.
SWR Resting Style.
This screen is used to select t
he way you want SWR displayed when you are not transmitting. The choices are… “-
.--
“, “1.00”, “. . . .”, blank and hold last SWR reading. If you select Hold Last, it will be reset when you transmit again. Use Dn/Up to cycle
through choices.
Lower Bargrph Mode.
This screen is used to select what parameter is displayed on the lower half of the display. The choices are SWR
and Reflected Power. If you select Reflected Power, remember that the reflected power will be referenced to either NET power or
Forward Power (F+R) depending on your earlier selection for the power display. F+R is the preferred choice to use with REF pwr. Use
Dn/Up to select.
Callsign Entry
. This screen is used to program your callsign into the screen saver. The Dn button is used to select the position of the
letter you want to change… 1 thru 6 from left to right. The Up button is used to scroll through the choices… 0 thru 9, A thru Z, space, /
and -. Both buttons wrap around. Step thru the positions, scrolling to the letter you want for each position. The callsign is saved as you
see it.
Display Brightness.
This screen is used set the display brightness. Each step represents a 12.5% change in brightness. The default
setting is 6, which equals a brightness level of 75%. This provides almost full brightness, and provides some measure of added display
life. You can use any brightness level you like. The display is rated for 50,000 hours (5.7 years) of continuous display at full brightness
before brightness drops to half. With the LP-100A
’s screen savers, you can expect much more than that with typical operating habits.
Use Dn to reduce brightness, Up to increase. The brightness of the screen changes as you adjust it.
Screen Save Timers.
This screen is used set the display screen savers. The two timers that can be set are the Scroll timer and the
Sleep timer. The Scroll timer sets the time in minutes from the last transmission to the time when your call sign starts scrolling across
the screen. The Sleep timer sets the time from the last transmission to the time when the display turns off. The Scroll saver should be
set first, since it also affects the Sleep timeout. Each can be adjusted for up to 10 minutes (20 minutes total). The screen saver extends
display life, and reduces power consumption and heat when the meter is idle. There is also a third screen saver timer, but it is factory
preset. It dims the screen to 25% one second after transmission ends when in the Main Mode. If Peak power mode is selected and the
hold time is set for 1 second or more, it dims at the end of the hold period.
Calibration
Calibration Initial Screen.
This screen simply identifies that you are in the Calibration mode.
Serial Number.
All LP-100As 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. On later versions, this screen name was changed to Serial Number to compensate for other hardware changes as
well as cable type.
Gain Zero Trim.
This screen allows band-by-band calibration of the balance of the gain detector. The process simply requires a good
quality dummy load. The Dn/Up buttons are adjusted until the resistance on the screen matches the resistance of your dummy load.
The LP-100A automatically saves the Cal constants for each band, indexed to frequency. The built-in frequency counter automatically
determines the frequency.
Phase Zero Trim.
This screen allows band-by-band calibration of the balance of the phase detector. The Dn/Up buttons are adjusted
until the phase on the screen reads zero degrees. The LP-100A automatically saves the Cal constants for each band, indexed to
frequency. The built-in frequency counter automatically determines the frequency.
Gain Slope Trim.
Allows setting the slope of the magnitude for proper Z at a value removed from 50 ohms. This can be done with any
reasonable known load in the 25 or 75-100 ohm range. I am also working on a calibrator kit to simplify this.
Phase Slope Trim.
Allows calibrating the phase detector. This requires a delay line of known value. In its simplest form, this can be
done by calculating the electrical length of an existing piece of coax in the 3-10
’ range, and matching the readout to the calculated
length at the frequency used for the calculation. More on this in the Calibration section. I am also working on a calibrator kit to simplify
this.
Summary of Contents for LP-100A
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