inspect all solder joints for quality, and touch-up any needing it. Inspect for
solder blobs or other possible shorts. Double check that all polarized
components have been installed properly.
Install the bottom cover to the enclosure, using the 1/2” screws and 1/4” spacers
at the bottom of the board, and the 1.5” threaded spacers at the top of the
board.
Locate a regulated 12v supply. Assemble a power cable using a 2.5x5.5mm
coaxial power plug, center positive. Fuse the line with a 1A fast-blow fuse.
Make up a cable for the key. Obtain an 1/8” audio plug, and wire your key to the
tip and shell. The shell is grounded, and the connector tip is the keying line.
ALIGNMENT
With the Cyclone power switch OFF, plug a pair of headphones or ear buds into
the headphone connector. Turn on the 12v supply, and the power switch of the
Cyclone. Advance the volume control fully. You should hear a slight hiss of the
audio amplifier circuitry.
If you hear hiss in the headphones, and the power supply fuse has not blown,
we may proceed with alignment.
The first task is alignment of the PTO coil. It is necessary to set the PTO
frequency at 4.000 MHz when the PTO screw is fully inserted. Press the FREQ
button at the side of the enclosure. You should hear a sequence of four CW
numerals played in the headphones. These four digits represent the count in
hundreds of kilohertz, tens of kilohertz, kilohertz, and hundred hertz. This
represents the transmit frequency, which is calculated in the counter IC by
subtracting the PTO frequency from the 11 MHz LO frequency.
If the PTO is aligned, the count should be 0 – 0 – 0 – 0. If the number begins
with a 9, then the PTO frequency is too high, and the PTO turns should be
spread. If the number is greater than zero, than the PTO frequency is too low,
and the coil turns should be pinched together toward the center of the coil form.
You will also notice a birdie in the headphones around a PTO frequency of 4.000
MHz. This serves as an audible band edge marker, and is a helpful tool to
assist in alignment of the PTO coil.
Once the PTO is within a kilohertz or two of 4.000 MHz, coat the PTO coil
winding with a thin coat of clear fingernail polish to fix the turns in place.
