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E-600 (E39)

Allwellenempfänger Autophon (All Wave Receiver 39), E39; developed and produced by Autophon AG, Solothurn.

Autophon got an order to develop an allwave superheterodyne receiver in 1938 and developed the E39 receiver, based on their surveillance and measurement receiver RD2679. The concept of a receiver with a triple main tuning condenser and plug-in coil sets with calibrated frequency charts was based on National's HRO receiver. The core component, the triple - tuning condensator PW-3 with the micrometer dial typical for National's receivers, has been acquired from that manufacturer in the USA.

Autophon E39

Technical Data

Power Supply

  • Mains: 110, 125, 145, 220, 250 V; 80 W
  • Accumulator / Batteries: 2 x 6,3 V NiFe - Accumulators 84 W (valve heaters), rotary converter for battery operation (Sets No. 7 - 100).

Sets No. 1 - 6 are for mains operation only, the accessory case houses a loudspeaker. Set No. 7 - 100 intended for field use come with a converter, so they can be operated from accumulators; in a standard setup, only headphones are used.

Dimensions

  • Receiver case E39: 450 x 450 x 310 mm, 41 kg
  • Accessory case E39Z: 450 x 450 x 310 mm, 48 kg
  • two NiFe-Accumulators Typ 5.11.JN.7 in wooden cases: 305 x 210 x 335 mm, 27 kg each

Accessories

  • A L-Antenna or directional frame antenne were used as standard aerials.
  • Headphones

E39 front view E39Z accessory case

Operation

The whole receiver came in two army-green boxes, the main receiver case and the accessory case with the coil set drawers and all necessary accessories and spares.

In the main receiver case, we find in the left upper corner of the front panel the mains connector and the socket for the cable connected to the 12V DC power supply in the accessory case.
In the middle, You find the mains voltage selector quite typical for Autophon sets using a plug that has to bee placed in the correct voltage position, and the mains switch.
The measuring instrument can be switched from signal level indication to plate and heaters voltage control, the controls underneath are the tone control and the AGC switch (Schwundausgleich = „Fading correction“).

In the left lower section, You find the controls for the BFO (there is also the possibility to regulate the level of the internally generated auxiliary carrier), the Sensitivity („Empfindlichkeit“) and Crystal filter bassband, the volume („Lautstärke“) and bandwidth („Bandbreite“).
On the right, You find the main tuning knob with it's micrometer 000 - 500 dial, this arrangement allows You to retune exactly to a known frequency, but do determine the exact corresponding frequency to the micrometer reading, You have to check the calibration chart - all of these have been drawn by hand for each receiver. Underneath, the corresponding coil set for each band has to be plugged in. Connect the antenna to the red aerial socket.

In an accessories case, You find some drawers containing the plugin coil sets some spares, headphones - there is also a 12V DC power supply converting (car) battery power to the necessary plate / B+ voltages for operating the receiver in this case.

This receiver is a technical marvel - it can be still be used for shortwave reception nowadays, but for „chasing the radiowaves“, a receiver with direct frequency readout makes things a lot easier. One technical drawback is remarkable, the single conversion set will get pass the intermediate frequency in the 1,2 - 2,86 MHz range, and reception will be disturbed around 1,6 MHz.

Technical Principle


The antenna signal has to pass a RF preamplifier stage (EF13) in ranges II - VIII, in range I (30 - 60 MHz), the RF amplifier section is deactivated becouse of insufficient specifications of the tubes available those days. The signal is converted to an intermediate frequency of 1600 kHz in the mixer stage (ECH11), this is followed by two IF amplifier stages (EF11, EF11). After having passed the crystal filter and another two IF amplifier stages (EF11, EF11), which are regulated by the AGC circuitry, the signal is demodulated (EBC11 and forwarded to the audio amplifier, it's output is sufficient for headphones operation.
IF signal from the output of the third IF stage is amplified (EBC11) to drive the signal strength meter.
For demodulation of CW and single sideband transmissions, the output of the BFO (ECH11) on 1601 kHz is mixed to the IF signal, the frequency and the output level of the BFO are adjustable.

Valve setup

V1 (EF13, RF stage); V2 (ECH11, mixer, main oscillator); V3 (EF11, 1. IF stage); V4 (EF11, 2. IF stage); V5 (EF11, 3. IF stage); V6 (EF11, 4. IF stage); V7 (EF11, AGC amplifier) and V8 (EBC11, diode system used for demodulation, triode as meter amplifier); V9 (EBC11, demodulation and AF amplifier); V10 (ECH11, BFO).
Gl (AZ12, mains rectifier), stabilizer STV 280/80, FeH regulator H85-255/80 for the stabilisation of the plate voltage of + 465 V).

Development

Autophon developed their control receiver RD2679 in 1937 and got a contract to develop the communication receiver E39 for the Swiss Army in late 1939. It's principle was based on National's HRO receiver with very similar plug in coils and calibration charts. The main component, the triple tuneable condensor PW-3 mwith it's characteristic „Micrometer dial“ was acquired from National.

Field use

In the years 1939/41, a total of 100 receivers have been built, the have been used in the Swiss Army until 1963.

Variants

  • E39, Prototype: according to KTA images, the first version had ventilation holes located above the main tuning knob.
  • E39, Mains only variant: THe sets No. 1 - 6 came with an internal speaker and only mains power supply, they carry the designations „AW1“ to „AW6“.
  • E39, Air Force variant: a number of sets has been ordered from the Air Force, they are intended for use on the airfields and have special coil racks. The carry designations „E39 Lx“.

Manuals

Additional information

en/e39.txt · Zuletzt geändert: 2024/08/03 08:21 von mb