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VHF Receiver E-604 (E46)

VHF Empfänger 46, E46; developed and produced by Autophon AG, Solothurn.

In parallel to their E52 / E44 receivers, Autophon developed a VHF - receiver; because of the use of the VHF range for military tactical communications was still quite far in the future, only a small test series of this receiver has been made on behalf of the Airforce / Anti-Aircraft troops.

Technical Data

Power Supply

  • Mains: 110, 125, 145, 160, 220, 250 V

Dimensions

  • Receiver case E46: 400 x 320 x 280 mm

Accessories

  • Headphones

E45 front view

Operation

The front panel is divided in two sections by the horizontal linear dial of the turret tuning arrangement. Above the dial, You find from the left hand the coaxial antenna connector and the sockets for connecting longwire antenna and earth, then the station clock, and the signal strength meter. This can be switched to indicate the heaters and plate / B+ voltages. At the right upper corner, You find the mains socket, the mains voltage selector and mains switch and some fuses.

Underneath the frequency dial, You find the rotary band switch operating the turret tuner - find the corresponding dial in the dial window - and at the right hand the main tuning knob with a mechanical blocking arrangement. Next to this one the switch for the two different IF bandwidths of +/- 20 and +/- 75 kHz.

In a row of controls below, you find from the left the volume control („Lautstärke“ or „Puissance“), the noise limiter switch, speaker and headphone jacks, the AGC/RF gain control, the BFO control for CW reception, the tone and the AM/FM reception mode switch.

Technical Principle

A neon buld is used to protect the receiver frontend from overloading. The RF signal has to pass two RF amplifier stages (EF50, each). It is then mixed with the signal from the main oscillator (EF50, Pos. 322) and converted to the intermediate frequency of 4.3 MHz in the mixer stage (ECH21, heptode system). The IF then is amplified in two IF amplifier stages (two EF50).
The signal is then feed into the ECH21; in AM (A3)-Mode, one grid of the ECH21 serves as rectifier for demodulation, in FM (F3)-mode, the ECH21 is used as limiter stage, the double diode 6H6 as diskriminator to demodulate FM transmissions.
The valve ECH21 is used as AF preamplifier stage, the EBL21 as AF final stage. The signal then will reach the hedphones and speaker jacks, two antiparallel selenium rectifier diodes serve as noise limiter.

Valve setup

V1, Pos. 474 (EF50, RF amplifier); V2, Pos. 424 (EF50, RF amplifier); V3, Pos. 374 (ECH21, mixer); V4, Pos. 322 (EF50, oscillator); V5, Pos. 205 (EF50, 1. IF amplifier); V6 , Pos. 176 (EF50, 2. IF amplifier); V7, Pos. 148 (ECH21, AM demodulator, FM limiter); V8, Pos. 130 (6H6, double diose as discriminator); V9, Pos. 54 (ECH21, AF preamplifier); V10, Pos. 40 (EBL21, AF final amplifier).
Gl1, Pos. 8 (AZ1, rectfier plate voltage), Gl2, Pos. 7 (AZ1, rectifier for all other voltages), Selenium rectifier Pos. 13 for grid voltage.

Development

Field use

In 1947, only a small preliminary series of eleven receivers of this set has been produced, only four of them remained with the Signals Comp. 20

Manuals

Additional information

en/e-604.txt · Zuletzt geändert: 2019/03/22 22:15 von 127.0.0.1