terminal emulator is connected, autostart is disabled. This is the main program which your U4B will
run during flight, whenever it powers up with sufficient power from the solar cells.
Frequency:
This is an information-only, non-editable field showing the center frequency of your
WSPR tracking transmissions. There will be a few Hz variation around this due to temperature
fluctuations – a TCXO such as the 25MHz TCXO synthesizer referenced used, is good – but does
not completely eliminate drift down to zero.
Telemetry format:
An information-only field indicating what format to expect the telemetry
transmissions (second WSPR packet) to be in; the first character will be one of 0, 1 or Q and the
third character will be numeric (0-9). All other characters of the WSPR callsign, locator and power
will be substituted by the QRP Labs telemetry.
Start minute:
the minute past the hour, repeating every 10 minutes, at which the first WSPR
transmission will be sent. In the example shown, the first (standard) WSPR transmissions will
occur at :06 :16 :26 etc past the hour. The telemetry transmissions are sent immediately after the
standard WSPR transmission.
3.2 Run program
This application simply runs the default program of the U4B, as defined in the Configuration
screen. By default, this program is called “TRACKER”. Any output printed from the program is
shown on the screen. The Run program application is useful for final testing of your flight program.
It can be useful to include debug PRINT statements that will help you to know that everything is
operating properly. During flight when there is no host PC terminal emulator connected, the PRINT
statements are harmless, they simply do nothing.
Each output line is prefixed by a timestamp in HH:MM:SS format indicating the system time.
U4B operating manual Rev 1.00
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