QRPKits KD1JV, Инструкция по эксплуатации

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Iambic mode. If A is currently enabled, B will be toggled on, the letter “B” will be annunciated and the display will show
[b . ]. Conversely, if B is currently enabled, the letter “A” will be annunciated, the display will show [A .] for a second and
then escape to normal operation.
The difference between A and B modes:
When using Iambic keying, holding closed both paddles will alternately send dots and dashes, with the first element being
determined by which paddle was closed first. The difference between A and B modes is what happens after the paddles are
released.
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In A mode, if both paddles are open during a inter-element space the keyer simply stops sending.
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In B mode, an extra and opposite element is sent from the last element being sent when the paddles are
released. This extra element always sent if both paddles are sensed to be closed at the same time. This means
care must be taken to release one paddle before closing the other if this extra element is not desired.
Straight key mode:
Straight key mode is activated if the Dash input is grounded when you turn on the rig. This automatically happens if a
monaural phone plug (normally used with a straight key) is inserted into the stereo paddle jack.
Tune up mode:
It is sometimes handy to be able to temporarily key the transmitter on and off manually with the paddle for measuring
power output or allowing an autotuner to do its thing (though this is not recommended).
This mode is activated by clicking and holding the <MENU> switch closed for 2 seconds. The letter “T” will be first
enunciated and then display will change to a character which sort of looks like a “t” when the switch is released and tune
mode becomes active.
The transmitter can now be keyed on and off with the paddle. When done, exit back to normal operation by clicking the
<MENU> switch again.
Speaker or headphones:
There is sufficient audio output power to drive a small 8 ohm speaker. Care should be taken when using headphones to
keep the volume turned now when tuning around the band. Although the audio AGC action will limit the volume of strong
stations, this can still be too much when using headphones.
Power supply voltages and fusing:
Power supply voltage to the Tri-bander should be between 13.8 and 9.5 volts. A physical fuse is not included in the board
or rig case. As a safety precaution, there is a narrow section of pcb track between the power jack positive output terminal
and D3, the reverse polarity protection diode. Should a short on the raw DC input supply occur, this narrow section of track
should burn out and will need to be repaired after the fault is found. Since this is a one time only protection feature, using
a fused supply (1 A) is highly recommended.
High SWR warning:
Operating this transmitter into a high SWR can result in damage to the PA MOSFETS. Open circuit is fine, short circuit is
okay for short periods (couple of seconds), but highly reactive loads need to be avoided. Damaging SWR can result when
using an antenna tuner as your trying to find a match. Auto-tuners can be a problem as they search for a match. The best
way to avoid this situation is to use a resistive SWR bridge. Reducing power is also acceptable, but the only way to do that
is to reduce the supply voltage to the rig. This can be done by switching a 10 ohm, 1 watt resistor in series with the power
supply positive lead, using a toggle switch.
Circuit description:
Microprocessor controller and DDS VFO:
The heart of the rig is the microprocessor controller and DDS VFO. An Atmel MEGA48 processor is used for the controller.
The MEGA48 controls the DDS VFO, drives the frequency display, implements the keyer functions, controls transmit and
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