Vectronics VEC-221K - Manual (Page 25)

VEC-221K Instruction Manual CW Memory Keyer Kit
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Use with vintage sets: Early tube transmitters and hybrid transceivers may not
be compatible with the VEC-221K. If the transmitter uses grid-block keying (a
negative key voltage), it can not be used with the VEC-221K. An example of a
grid-block keyed transmitter is the Heathkit DX60. Check the ARRL handbooks
for circuits for adapting keyers to grid-block keying.
Vintage novice transmitters commonly used cathode keying, a combination of
high current and high voltage. The Heathkit DX40 used cathode keying, for
example. In general, most cathode-keyed transmitters should be compatible with
the VEC-221K keying circuit, so long as the 50 Vdc and 100 mA limits are not
exceeded.
Dot-and-dash memories and iambic keying: The dot and dash memories
making sending CW easier. The memory allows the user to key a dot before the
completion of a dash, and vice-versa. This feature maybe checked by setting the
keyer to the lowest speed and tapping first the dash lever and then the dot lever
before the completion of the dash. The keyer will generate both the dash and the
dot with perfect spacing. Test the dash memory in a similar manner. First tap
the dot lever and quickly tap the dash lever. The keyer will send the dot
followed by the dash, again with perfect character spacing.
Iambic paddles allow both paddles (or levers) to be depressed at the same.
Pressing (squeezing) both paddles simultaneously will generate a continuous
stream of alternating dots and dashes. The first paddle contacted determines
whether a dot or dash occurs first. CW characters such as "C", "K", "Q" and
"R" are very easily generated with iambic paddles.
Non-volatile memory: The non-volatile memory is used to store the serial
number, the keyer settings, and the four message memories. Because it is non-
volatile, it does not require battery backup to preserve the memory.
Special Functions
Note: All programmable special functions are saved in non-volatile memory.
These settings are restored at power on.
Automatic mode: Early telegraphers used a mechanical device called a bug to
send high-speed code. The bug would automatically send a string of dits when
the dot paddle was depressed and held. Bugs did not generate strings of dashes,
the dash had to be depressed once to generate each individual “dah”. The VEC-
221K normally operates in the fully automatic mode. However, it may be set for
“semi-automatic” operation, to emulate the sound and feel of a mechanical bug.
Weight: A 3:1 ratio between dit’s and dah’s is considered to be optimum. Some
operators prefer slightly different ratios; and the VEC-221K weight is adjustable
from 25 to 75% of a dot to suit those preferences. The factory default is 50%, or
3:1 dash-to-dot ratio.