TECHNICAL SUMMARY POWER OUTPUT: 10 volt-amperes (20 volt-ampere peaks}, continuous, from dc to 500 kc into a 1,000 ohm resistive or reactive load; 10 watts (Z0 watt peaks}, continuous, from 1 cps to 1 me into a 600 ohm resistive load. See Note 2 on Page 7 and Figure II. OUTPUT VOLTAGE: Greater than 105 volts rms (300 volts peak to peak) open circuit from dc to 1 me; 100 volts rms (280 volts peak to peak) across 1, 000 ohms from dc to 500 kc; 78 volts rms (218 volts peak to peak) across 600 ohms from I cps to 1 me. OUTPUT CURRENT: Above 1 cps, greater than 210 ma rms (£300 ma peak) through 10 ohms; 130 ma rms (±180 ma peak) through 600 ohms; 100 ma rms (±140 ma peak) through 1,000 ohms. Below 1 cps, 42 ma rms (±60 ma peak) through 10 ohms; 52 marms.(afc75 mapeak) through 600 ohms; 100 ma rms (±140 ma peak) through 1, 000 ohms, OUTPUT REGULATION (from no load to full resistive load): Less than 2% from 10 cps to 100kc, less than 5% over the entire frequency range. INTERNAL IMPEDANCE: Less than 10 ohms from 10 cps to 50 kc, less than 50 ohms from dc to 100 kc and less than 100 ohms above 100 kc. LOAD IMPEDANCE: Matching, nominal 600 ohms from 1 cps to I me; below 1 cps, 1, 000 ohms minimum load for full power output. See Figure 8. Minimum load, 10 ohms. See Figure 10. LOAD POWER FACTOR: Unity to zero, lagging or leading, OUTPUT DC LEVEL: Zero volts at capacitor-coupled AC OUTPUT terminals; nominal zero volts at the DC OUTPUT terminals. OUTPUT DC LEVEL STABILITY {typical, after initial warm up, expressed in per cent of peak output voltage): ±0. 02% in any one-hour period at fixed line voltage and ±0. 2% for ±10% line voltage change in all positions of the INPUT SELECTOR switch except the X1Ö DC and POT DC positions where ±0. 1% and ±1% apply, VOLTAGE GAIN: Maximum of 10, variable continuously, fixed gain of i0± 10% (20±1 db), or fixed gain of 1 ± 10% (0 ± 1 db) as determined by the INPUT SELECTOR switch. Less than ±0. 25 db change in gain for a 10% change in line voltage within the operating range. FREQUENCY RESPONSE; Flat within ±1 db from dc to 1 me under all specified operating conditions; approximately 3 db down at 2 me. See Figure 10. PHASE SHIFT: Zero ±1 degree from dc to 10 kc in the XI0 and POT positions of the INPUT SELECTOR switch. See Figure 13, In the XI position the phase shift is 180 ±1 degrees. HARMONIC DISTORTION (rms): At full power output, less than 0. 1% from 20 cps to 50 kc, less than 0. 5% from near dc to 100 kc and less than 3% above 100 kc. In the XI positions of the INPUT SELECTOR switch the distortion is less than 5% above 100 kc. See Figure 12. DC linearity is within +1% with loads above 500 ohms. HUM AND NOISE (referred to output): Less than 10 mv with the input shorted and less than 20 mv with an open circuit input. DYNAMIC RANGE: Approximately 80 db* SQUARE WAVE RESPONSE: See Figure 9. INPUT IMPEDANCE: Greater than 1 megohm in parallel with approximately 50 uuf in the fixed gain positions; 5, 000 ohms in parallel with approximately 50 uuf in the variable gain positions. INPUT COUPLING: Either direct coupling or capacitor coupling with a low cut-off frequency o£ 1 cps,_ INPUT SENSITIVITY: 7. 8 volts rms with a 600 ohm load and 10 volts rms with a I» 000 ohm load for 10 watts output at maximum gain (XI0). INPUT VOLTAGE LIMITS: 4.00 volt maximum dc component in the ac coupled {1 CPS) fixed gain positions; combined input signal voltages (ac and dc) must not cause more than 2 watts dissipation in the 5, 000 ohm GAIN potentiometer in either variable gain position, AMBIENT TEMPERATURE AND DUTY CYCLE; Continuous duty at full 10 watt output up to 5G°C (122°F) ambient. FRONT PANEL CONTROLS: INPUT SELECTOR switch. GAIN control. OUTPUT DC LEVEL control (screwdriver adjust). POWER ON switch. TERMINALS: Two multi-purpose binding posts for the INPUT (signal and ground)and three for the OUTPUT (DC signal, AC signal and ground). POWER REQUIREMENTS: 105-125 or 210-250 volts; single phase; 50-60 cycles; 250 watts. FUSE PROTECTION: Line: 2. 5 ampere slow-blow. Plate supply: 3/16 ampere slow-blow. TUBE COMPLEMENT (furnished with instrument): 2-6GT5, 2-6CL6, 1-6AQ5, 1-12AX7, 1-6AS7-GA, 1-6BK7-B, I-5R4-GYB. FORM: Furnished in an attractively styled perforated steel cabinet with a. cast aluminum front panel and frame. Front panel finished in gray enamel; frame and cabinet in blue enamel. Other finishes available on special order. Over-all dimensions Model DCA-IO: 7 I /Zu wide, 10” high, 15" deep. Weight 35 lbs. net, 40 lbs. shipping.