Keying-Line Specs for Various HF Tube Amplifiers

  1. The Heathkit SB-200 and SB-220 amplifiers have a keying voltage/current rating of -135V/3A and +120V/2A respectively. The best interface for these is either an electromechanical relay,  the Harbach Electronics SK-200/SK-220 or the Ameritron ARB-704.

  2. The Kenwood TL-922/A keying line is rated at +120V/80mA. Refer to the QSK922 site.

  3. The Yaesu FL- 2100B keying line is rated at -16V/125mA. (Specs courtesy Charles, WB6IYM.)

  4. 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.) Here is a list of keying parameters for all Alpha models.

  5. Several older amplifiers use 120V AC mains voltage for keying.

  6. Ameritron AL-1200 (typical): Keying: requires relay closure or sinking to ground of positive (+) 12 VDC at 100 mA, phono jack (excerpted from AL-1200 manual, on the Ameritron site).

  7. The Collins 30L-1 keying line is rated at -170V/80mA.

If you would like to contribute keying-line information on other amplifiers, please e-mail the webmaster.
Copyright © 2002 A. Farson. All rights reserved.
Last updated: 09/03/2005

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