87A MANUAL   SCHEMATIC 1   SCHEMATIC 2
The Ultimate Fully Automatic Linear HF Amplifier
Description
The 87A Omega is the finest amplifier you can buy, bar none - entirely "hands-off" in normal operation. It connects easily to transceiver, power mains and antenna(s), BUT, when you transmit, the 87A’s microprocessor-based control system does everything for you except talk. The 87A automatically re-peaks for optimum efficiency and linearity while you transmit and compensates for high or low drive power.

Alpha Radio Products provides a four-year, non-prorated factory limited warranty. Our amplifiers are built and tested in our facility in Boulder, Colorado. You know you can count on us to support both your new and all legacy ALPHA amplifiers ...we carry on the tradition of 30 years of being there for you! .

Features
  • Capable of 1.5kW continuous RF ouput on all commonly used modes and on any authorized amateur frequency from 1.8 to 29.7 MHz with no time limit
  • Full CW Break-In (QSK) and all digital modes
  • Compatibility with popular amateur transceivers and exciters
  • AlphaMax firmware comes with added features to readjust output network, trim tune, and readjust loading to prevent distortion due to overdrive.
  • 4-year Alpha Radio Products limited warranty 30-day money-back guarantee
Gold Plated RF deck
Specifications
Band Change & Tuning: matic under microprocessor control; average time required for complete bandchange and tuneup, <1 second. No special cables or connections required.
Frequency Coverage: All amateur bands 1.8-29.7 mhz* plus most non-amateur frequencies 6.0-19.0 mhz and 20-30 MHz.
Power Output: 1500 watts pep, keyed cw, or continuous carrier, no time limit. Auxiliary cooling fan (optional) recommended for very high duty cycle continuous operation i.e. contesting & RTTY.
Drive Power: Typically 50 to 55 watts for full rated output.
Input VSWR: < 1.5:1 within amateur bands; < 2:1 elsewhere.
Tube Complement: Two Eimac 3CX800A7 triodes in grounded grid.
T/R System: Heavy duty PIN diode switch capable of feedthrough and hot switching of 150W exciter power. Switching time approximately 1ms. Enclosed mechanical bypass relay.
ALC: Grid-current-derived, -10v maximum, adjustable gain.
Harmonic Output: Better than 50 db below rated output.
Intermodulation: Better than 35 db below rated output.
Fault Protection: Plate current, grid current, load VSWR, T/R sequencing, gain (i.e., severe mistune or RF arc), overdrive, open heater, overtemperature, others.
Displays: Led bargraphs for peak pout, prefl and switched bargraph for ip, hv and tune indicator.
Cooling: Full cabinet ducted air, rear intake/top exhaust. Floating blower mount for quietest operation.
Primary Power: 190-250V (200, 220, 240V nominal taps), 50-60 Hz, single phase; fused 20A.
Size & Weight: 17.3" W x 7"H x 16.5" D (439 x 178 x 419 mm) excluding controls, feet, and connectors. 75 lb. (34kg) net.