microHAM SMORF, Руководство пользователя

Страница: 18 / 76

micro HAM © 2015 All rights reserved
SCREEN MENU
This menu serves for setting up the SCREEN to meet user requirements. SCREEN Menu contains data which
are the same (but independently adjustable) for each SCREEN, as well as data specific to particular SCREEN
e.g. trigger source for Oscilloscope screen or display type for Spectrum screen. These specific data will be
explained in individual SCREEN TEMPLATE chapters, here we describe common settings for all screens.
1.
AVG ATTACK/DECAY
•
Sets averaging time constants used for average values (AVG).
Range: 0 – 2000ms, Step: 10ms.
2.
UPDATE
•
Sets update rate of numerical AVG values.
Range: 0 – 1000ms, Step: 10ms
3.
PEAK HOLD
•
Sets for how long the peak value is kept displayed till resets to new, lower peak value. Higher peak
value overwrites old peak value immediately.
4.
TUNE JUMP
•
Enables or disables automatic switching to TUNE screen when SMΩRF detects tuning signal. When
this function is enabled, SMΩRF inspects incoming signal waveform and if waveform matches
defined criteria for “tuning detection” automatically jumps to the TUNE screen. When tuning signal
disappears (waveform changes character), screen returns back from TUNE to original screen.
Special ability of the SMΩRF is to suppress power overshoots. These
overshoots can be caused by poor power supply regulation and ALC.
Virtually every transceiver generates overshoots at the beginning of
transmission until ALC loop stabilizes (hundreds μs up to several ms).
Exact time and amplitude of overshoots can be easily measured on the
Oscilloscope screen (described later).
SMΩRF has very fast measurement and reliably captures every overshoot with multiple samples. Once you are
aware that this happens, it can be annoying to see “bumped” peak and peak hold values on regular basis every
time ALC loop timeouts and transceiver generates new overshoot. To help with this problem, SMΩRF allows to
turn on filter to SUPPRESS OVERSHOOTS.
5.
SUPPRESS OVERSHOOTS
•
YES enables overshoot suppressing filter. This function is not generally applicable to all screens
when enabled. Advanced metering screens like the Oscilloscope or the Spectrum screens
intentionally do not suppress overshoots. Also please note, that suppression filter will have impact to
peak reading amplitude of SSB signals, where peaks of short duration are normal. Therefore for SSB
screens is recommended to turn suppression off (NO).
6. TIME
•
Sets time used by overshoot suppressing filter. Exact value is specific to every transceiver and can
be measured on the Oscilloscope screen. Good value to start with is 2ms.
18
Oscilloscope screen showing ALC overshot on initial
dot of CW signal (“bump” on leading edge).