The President Washington 100W can draw about 12 amps max on SSB at 13.8 V, based on retailer specs listing a 12 A maximum current intake for the unit.

In practical use, the actual draw on SSB will usually be lower than that and rise with power output, modulation, and voice peaks. A good rule of thumb is to size the power supply for at least 12 amps continuous , with extra headroom if you want clean operation and less voltage sag.

What that means

  • Rated SSB output: up to 80 W PEP on several current listings, though some sellers also advertise a 100 W variant.
  • Supply requirement: 13.8 V DC and roughly 12 A max current consumption on the 80 W listing.
  • Practical setup: a 12 A supply is borderline but workable at lower drive; a 15–20 A supply gives more cushion.

Quick answer

If you mean the current President Washington 10/12 meter radio sold as the 100W version, expect around 12 amps maximum on SSB , with typical speech current lower than that.