The Heathkit SB-200 and SB-220 amplifiers have a keying voltage/current rating of-135V/30mA and +120V/30mA respectively. The best interface for these is either anelectromechanical relay, the Harbach Electronics SK-200/SK-220 or the Ameritron ARB-704.
The Heathkit SB-1000 amplifier has a keying voltage/current rating of +12V/100mA. This is an inductive load; a keying buffer is strongly recommended.
The Kenwood TL-922/A keying line is rated at +120V/80mA. Refer to the QSK922 site.
The Yaesu FL- 2100B keying line is rated at -16V/125mA. (Specs courtesy Charles, WB6IYM.)
Recent Alpha amplifiers have a 28V/7mA keying-line rating. (Alpha 99's manufactured after 12/15/2002 have a 12V/7mA keying-line rating.)
Some Henry amplifiers have a 17V/240 mA keying-line rating. This is an inductive load; a keying buffer is strongly recommended.
Several older amplifiers use 120V AC mains voltage for keying.
Ameritron AL-1200 (typical): Keying: requires relay closure or sinking toground of positive (+) 12 VDC at 100 mA, phono jack (excerpted from AL-1200manual, on the Ameritron site).
The Collins 30L-1 keying line is rated at -170V/80mA.
Last updated: 09/25/2019