Model Number   HD-1Ø
Serial Number  3ØØ87
Production Run 1965 - 1974
Base size      4" X 8"
     finish    Two Tone Green
Aquired        January 2ØØ2

Single-paddle keyer (used micro switches).
First keyer kit. Heath may have sold more
than 5Ø,ØØØ HD-1Øs (WA7ZZE).

Model Number   HD-141Ø
Serial Number  Ø5639
Production Run 1975 - 1984
Base size      4.75" X 5.5"
     finish    Two Tone Green
Aquired        March 2ØØ1

Model Number   HD-1416
Serial Number  Ø3635
Production Run 1975 - 1986
Base size      3.5" X 4"
     finish    Two Tone Green
Aquired        March 1981

Model Number   SA-5Ø1Ø
Serial Number  Ø8-52516
Production Run 1981 - 1985
Base size      3.75" X 5.75"
     finish    Two Tone Gray
Aquired        October 1996