Ability to auto-replay any of the memories. This is how the beacon is implemented. The ability to turn the output on or off directly from a memory. This is used to turn on a solid carrier when operating a beacon. This, combined with the variable attenuatoin, makes a very good propagation beacon.
Low parts count.
The keyer will be built on a PC no larger than 2 by 4 inches. The goal will be to reduce this size as much as possible. The PC board will include appropriate test points to aid in the construction and test. The keyer should draw no more than 20ma of current at 12 VDC for normal operation. The attenutor may require some additional power.