Equipment information

Drake L-4 Amplifier
Manufacturer:
Model:
L-4
Date:
Category:
Group:
Description:
Linear Amplifier

Information

The R L Drake model L-4 Linear Amplifier offers continuous 2000 watt PEP-SSB, and 1000 watt D.C. CW, AM and RTTY operation covering the ham bands 80 through 10 meters. All frequencies 3.5 to 30 mHz may be covered with some retuning of the input coils. The L-4 Linear Amplifier was designed to match the TR-3 and TR-4 Transceivers and T-4/T-4X Transmitters in appearance and drive requirements to run the maximum legal input power. The L-4 uses two 8163 or two 3-400Z zero bias triodes in a Class B grounded grid circuit configuration that utilizes R.F„ negative feedback for lowered odd order distortion products. A transmitting AGC circuit controls the exciter gain to allow the highest average power without peak clipping. An internal changeover relay feeds the Antenna through when the L-4 is turned off. A pair of relay contacts bias the output tubes to cutoff, eliminating unwanted heat and diode noise when receiving. The output tubes are forced-air cooled by a very quiet low velocity, high volume internal blower. Two taut-band suspension meters indicate plate current, grid current, plate voltage, and relative R„F. output power. The separate solid state Power Supply requires no warm up period and provides excellent dynamic and static voltage regulation.

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Service and User Manual
Manual Type:
Service and User Manual
Pages:
28
Size:
11.31 Mbytes (11856855 Bytes)
Language:
english
Revision:
Manual-ID:
Date:
Quality:
Scanned document, reading partly badly, partly not readable.
Upload date:
2017 08 09
MD5:
771c37bb09e2a72c21295ad0b9e7ebe5
Downloads:
816

Information

GENERAL SPECIFICATIONS ... 1 DESCRIPTION ... 3 INSTALLATION INSTRUCTIONS ... 4 A. Unpacking ... 4 B. Tube and Chimney Installation ... 4 C. Location ... 5 D. Power Requirements - 115 V and 230 V Operation ... 5 E. Jumper Connection Diagrams ... 6 F. Low Pass Filter ... 7 G. Antenna Requirements ... 7 H. Ground Requirements ... 7 I. Exciter Requirements ... 7 J. Transmitting AGC ... 8 K. VOX ... 8 L. Initial Connection Diagrams ... 9 M. Viewing Angle Options ... 10 TUNING PROCEDURE ... 11 A. CW, RTTY ... 11 B. SSB, AM ... 13 OPERATION ... 14 A. CW, RTTY ... 14 B. SSB ... 14 C. AM ... 15 THEORY OF OPERATION ... 16 SERVICE DATA ... 17 A. Amplifier ... 17 1. Removing Top Cover ... 17 2. Removing Bottom Cover ... 17 3. Removing Front Panel ... 17 4. Cleaning Amplifier Compartment ... 17 5. Tube Replacement ... 18 6. Input Switch Drive Belt Replacement ... 18 7. Troubleshooting ... 18 B. Power Supply ... 19 1. Circuit Breaker Reset ... 19 2. Removing Bottom Cover ... 19 3. Removing Top Cover ... 19 4. Troubleshooting ... 19 ALIGNMENT ... 21 A. Input Coil Adjustment ... 21 B. Meter Adjustment ... 21 C. Knob Pointer Alignment ... 22 SCHEMATICS ...

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