DRAKE L-4B Instruction Manual

The DRAKE L-4B is a powerful linear amplifier that provides continuous 2000 watts PEP SSB and 1000 watts DC for CW, AM, and RTTY operation on ham bands 80 through 10 meters. It features two 3-500Z or 8802/3-500Z, 8163, or 3-400Z zero bias triodes in a Class B grounded grid circuit configuration with RF negative feedback for low odd order distortion products. The L-4B includes a transmitting AGC circuit to control the exciter gain for maximum power without peak clipping, an internal changeover relay that feeds the antenna through when the amplifier is off, and a pair of relay contacts that bias the output tubes to cutoff for eliminating unwanted heat and noise during receive. The L-4B is forced-air cooled by a low velocity, high volume internal blower and includes two taut-band suspension meters for plate current, grid current, plate voltage, and relative RF output power. The separate solid state power supply requires no warm up period and provides excellent dynamic and static voltage regulation.

PDF Download
Document
DRAKE L-4B Instruction Manual | Manualzz

Advertisement

Advertisement

Advertisement

Key features

  • Handles PEP-SSB (2000 watts), and DC. CW, AM, and RTTY operation (1000 watts)
  • Covers ham bands 80 through 10 meters
  • Utilizes RF negative feedback for lower odd order distortion products
  • Incorporates transmitting AGC circuit
  • Has internal changeover relay
  • Employs a pair of relay contacts to bias the output tubes to cutoff when receiving
  • Uses forced-air cooling for output tubes
  • Provides two taut-band suspension meters for plate current, grid current, plate voltage, and relative RF output power

Frequently asked questions

The DRAKE L-4B covers the ham bands 80 through 10 meters, and all frequencies from 3.5 to 30 MHz with some alteration of the input circuit.

The DRAKE L-4B has a plate input power of 2000 watts PEP - SSB, and 1000 watts DC on CW, AM, and RTTY.

The DRAKE L-4B uses two 3-S00Z or two 8802/3-S00Z or two 8163 or two 3-400Z zero bias triodes.

The DRAKE L-4B has an input impedance of 50 ohms.

The DRAKE L-4B has an adjustable pi-network that matches 50 ohms with an SWR not exceeding 2:1.

The DRAKE L-4B has intermodulation distortion products in excess of -33 DB.

The DRAKE L-4B requires 230 volts 50 - 60 Hz 15 amperes, or 115 volts 50 - 60 Hz 30 amperes.
Preparing document for printing…
0%