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Collins 75A-2

Collins 75A-2


Introduction Date / Price: 1950 / $440
Tube List: 0A2 (1), 5Y3GT (1), 6AL5 (3), 6AQ5 (1), 6BA6 (6), 6BA7 (2), 6CB6 (1), 12AT7 (1), 12AX7 (1).


Description:

The Collins 75A-2 receiver is dual conversion and covers the 160 thru 10 meter amateur bands. Selectivity choices include five positions for the crystal filter (approximately 5 kc to 200 cps bandwidth) and that of the 455 kc IF transformers for AM operation. The crystal phasing circuit provides a tunable notch rejection for phasing out interference heterodynes. Operating modes for the receiver include AM, CW, MCW. Accurate tuning is accomplished through the use of a slide rule drum dial calibrated in .1 Mc and a vernier dial calibrated in 1 kc increments (2 kc increments on the 10 and 11 meter bands). Separate noise limiters are used for AM and CW operation. Front panel controls include: Band Switch, Main Tuning, Tuning Zero Set, On-Off-Standby Switch, RF Gain, AF Gain, Crystal Selectivity Switch, Crystal Phasing Control, CW-AM-FM Mode Switch, CW Pitch Control, Noise Limiter - Calibrate Switch, CW Limiter Control, and Antenna Trim. An optional 100 kc crystal calibrator (8R-1) is available as a plug-in unit. Other options include a plug-in NBFM adapter (148C-1) and external cabinet mounted speaker (270G-2).

Specifications:

FREQUENCY RANGE:
160 Meters: 1.5 - 2.5 Mc
80/75 Meters: 3.2 - 4.2 Mc
40 Meters: 6.8 - 7.8 Mc
20 Meters: 14.0 - 15.0 Mc
15 Meters: 20.8 - 21.8 Mc
11 Meters: 26.0 - 28.0 Mc
10 Meters: 28.0 - 30.0 Mc

MODES:
AM, CW, MCW

TYPE OF SERVICE:
Fixed Station operation.

POWER REQUIREMENTS:
115 vac, 50-60 cycles; power consumption is approximately 85 watts.

IMAGE AND SPURIOUS REJECTION:
Image rejection better than 50 dB. IF rejection is better than 50 dB

CALIBRATOR:
100 kc crystal oscillator (optional).

FREQUENCY STABILITY:
Drift is negligible after warm-up and varies only slightly with line voltage variations.

BANDSPREAD:
Approximately ten turns of the vernier dial per frequency range.

VISUAL DIAL ACCURACY:
Within 1 kc (160 - 15 meter bands), within 2 kc (10 and 11 meter bands).

SENSITIVITY:
2 uv for 10 dB signal-to-noise ratio.

SELECTIVITY:
Crystal Filter, 5 positions: 4 kc to 200 cycles nominal (6.0 dB points).
Fixed I.F.: 13 kc (60 dB points).

AVC:
Audio output level is within 6 dB for an RF input change of 5 uv to .5 v. Delayed, amplified AVC circuit.

VARIABLE FREQUENCY OSCILLATOR:
70E-12 permeability tuned oscillator (PTO).

ANTENNA INPUT IMPEDANCE:
50 to 150 ohms nominal (unbalanced, balanced).

AUDIO OUTPUT LEVEL:
2.5 watt at AGC threshold.

AUDIO OUTPUT REQUIREMENTS:
Speaker: 3-4 ohms / 500 ohms.

PROTECTIVE DEVICES:
Fuse in ac line.

SIZE:
Receiver: 21 1/8" W, 12 1/2" H, 13 1/4" D.

WEIGHT:
70 lbs (shipping wt).



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