[Amps] Re: Drake L7 Newbie

[Dennis Sokol]

You can run the amp on CW safely in the SSB mode with no problems. These amps were built when the output power limit was 1000 watts DC average input.  I have operated my SB-220 on cw in the SSB mode for hours on end with no problems. In my SB-220, the resting plate voltage
was about 3100, dropping to about 2600 under full load. Your results will vary with your line voltage. Besure to use 230 volts input, not 117V.

The 2400 volts on the L7 seems a bit low. The key to excellent power out in the L7/L4 is to rebuild the power supply, primarily with a bridge circuit rectifier using a xformer with about twice the high voltage output and current ratings. See W2CQM's excellent Drake L4B article for more ideas.

73, Dennis W0JX