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E-611: Hallicrafters SX-23

E-605, All Wave Receiver SX-23; developed and produced by Hallicrafters Co., Chicago IL.

The number of sets aquired by the army and the exact role of the receiver is not known.

Technical Data

Power Supply

Dimensions

  • 480 x 235 x 318 mm, 23 kg

The SX-23 comes in a 48 x 23.5 x 31.8 cm large metal cabinet, a hinged lid gives access to the inside for tube replacement.

Accessories


Operation

The Super Skyrider SX-23 has an Art Deco case unique to this Hallicrafters radio. In contrast to earlier receivers made by Hallicrafters, the round metal frequency dial is covered behind a shutter, but it is not transparent unklike the backlit dials found in later sets. The round dial rotates behind a sector-shaped window, a small window on the left is for the signal strength meter and the one on hte right indicates the selected band.

The band switch is located below the main dial, on the left there are the marks of the four amateur bands, on the right the „general coverage“ ranges without bandspread: With then covering 540 kHz - 1.7 MHz, 1.7 - 5.2 MHz, 5.2 - 16.5 and 16.5 - 34 MHz, the receiver covers the entire medium and shortwave range. The main tuning knob is not original in my unit, originally, there was a typical „steering wheel knob“. In the bandspread amateur radio ranges, the frequency can be determined using a log scale and calibration card.

To the left of the main dial is the control for the BFO used for CW reception (in my set, the „steering wheel knob“ found a second use here). Below are the controls for the bass - treble, which is coupled with the power switch, an arrangement found in several early Hallicrafters receivers. Next to it the controls for the A.F.Gain (the volume knob) and the R.F.Gain (the high frequency amplification gain). Below next to the headphone jack, the switches for the noise limiter and a transceive - receive switch to operate the set in an amateur radio environment in cooperation with a transmitter.

On the lower right of the front panel is the bandwidth switch, which is coupled to the AVC control, the automatic gain control. With the AVC switched off, a narrow quartz filter for telegraphy reception, a slightly wider one for telephony reception and a narrow coil filter can be selected. In the right positions the AVC is activated, a quartz filter for telephony, a narrow and a wide coil filter can be selected.

Technical Principle

The RF signal coming from the antenna connector is first amplified (6SK7) and then converted in the first mixer (6SA7) to the intermediate frequency of 455 kHz; in the oscillator a 6SJ7 is used. After two IF amplifier stages (6SK7, 6SK7), the signal is demodulated (6SQ7) and after a preamp stage fed to the AF output stage (6F6). The BFO (6SJ7) is activated for CW and single-sideband reception. A 6B8 is used for the AVC, in the noise limiter, a 6H6 dual diode is used.

The eleventh tube used in the power supply is the full-wave rectifier tube 80.

Valve setup

V1 (6SK7, RF preamplifier); V2 (6SA7, mixer stage); V3 (6SJ7, oscillator); V4 (6SK7, 1st IF stage); V5 (6SK7, 2nd IF stage); V6 (6SQ7, demodulation and AF preamplification); V7 (6F6, AF final stage); V8 (6SJ7, BFO), V9 (6B8, AVC); V10 (6H6, noise limiter).

V11 (80, mains rectifier).

Development

Field use

Information about the purpose of the E-611 / Hallicrafters SX-23 in the Swiss Army is missing, the receiver is likely to have been in use for radio monitoring purposes.

Manuals

Additional information

en/e-611.txt · Zuletzt geändert: 2019/03/28 08:52 von 127.0.0.1