Drake R-4C

drake-R-4C

Modes of Operation: SSB, CW, AM, RTTY.
Sensitivity: SSB Mode: 10 dB signal-plus-noise to noise ratio obtained on 80 M-10 M amateur bands with less than a 0.25 microvolt signal on the antenna terminal, on other frequencies less than 0.5 microvolt signal.
Selectivity: Covers 3.5 to 4.0 MHz, 7.0 to 7.5 MHz, 14.0 to 14.5 MHz, 21.0 to 21.5 MHz, and 28.5 to 29.0 MHz.
15 accessory crystal sockets are provided. Coverage of any additional 500 kHz ranges between 1.5 and 30 MHz (except between 5.0 and 6.0 MHz) can be added by installing accessory crystals.

As supplied:

SSB Mode: 2.4 kHz at 6 dB, 4.2 kHz at 60 dB.
AM Mode: 8.0 kHz at 6 dB, 28 kHz at 60 dB.

With accessory crystal filters:
AM Mode, 2 filters available:
6.0 kHz at 6 dB, 10 kHz at 60 dB.
4.0 kHz at 6 dB, 7.5 kHz at 60 dB.
CW 1.5, CW .5, CW .25 Modes, 3 filters available:
1.5 kHz at 6 dB, 3.0 kHz at 60 dB.
500 Hz at 6 dB, 1000 Hz at 60 dB.
250 Hz at 6 dB, 600 Hz at 60 dB.

Stability : After warm up, frequency will not drift more than +- 100 Hz, including
voltage variation of +- 10%.

Calibration: Better than +- 1 kHz when calibrated at nearest 100 kHz calibration
point.

Spurious Responses: Internal spurious response less than the equivalent of a 1 microvolt
antenna signal on all amateur bands.

Image Rejection: (11.29 MHz above desired): Over 70 dB below 23 MHz, 60 dB above
23 MHz.

Input Impedance: 52 Ohms nominal.

Audio Output Impedance: 3.2 Ohms to speaker, or headphones, 3000 Ohms anti VOX.

Audio Output: 0.7 Watt at AVC threshold, 2 Watts maximum at less than 5% T.H.D.

AGC: Audio Output increases 3 dB maximum for a RF input increase of

100 dB above AGC threshold. AGC threshold typically 1 microvolt.

Attack time: 1 millisecond

Release times: Slow: 1 second

Medium: 350 mSec
Fast: 50 mSec