The shortwave receiver Telefunken E 863 Kw/2 which makes part of the shortwave long distance receiving system Telefunken Transradio 21 has been in use with Swiss Authorities. It carried the Swiss Army designation E-653 and was used for shortwave communications with Swiss embassies. I have no further informations about the number of systems and their specific role.
The Telefunken E863 Kw/2 is a design of the seventies. It's a modular solid state surveillance and communications receiver, it makes part of Telefunken Transradio 21 - 26 long range reception system in which it is used with modules for FSK reception.
The receiver itself has the width of a half of a 19" rack, it's dimensions are 256 x 270 x 324 mm, in the desktop cabinet 274 x 315 x 350 mm and it's weight 18 or 22 kg respectively.
The receiver can be powered from 110 or 220 V mains and has a power consumption of 100 W while heating up, it can be powered by 21,5 - 30 V DC alternatively.
The headphones socket is situated on the front, all other connectors on the rear face of the receiver. According to the variant and the designation country of an export set, the frontpanel carries a german language lettering or only international symbols.
The frontpanel design is somewhat unusual: in the left upper corner, you find the main switch with the positions OFF / Warm up / normal operation / operation with monitor speaker off. A six digit nixie tubes frequency display will indicate the reception frequency with a resolution of 100 Hz.
In the left lower corner, you find six switches: in the top row the bandwidth switch for the +/- 100 Hz, +/- 250 and 750 Hz filters for CW reception, +/- 1,5 kHz, +/- 3 and 6 kHz for AM reception and two 3 kHz USB and LSB filters. Next to it, you find the band selector to switch one of the ranges 1,5 - 3,48 / 3,47-7,49 / 7,45-15,5 and 15,4-30 MHz. In the middle row, there is the BFO control and the reception modes switch. This is slightly compley to operate: the first three positions select the automatic RF gain control AGC with short and long time constants for the modes F1/F6 (FSK) and A2/A3 (AM). In the middle positions, AGC is turned off and maunual gain control active for the A2/A3 (AM), A3J (SSB) and A1 (CW) modes, and the last two positions activate AGC for A1 (CW) and A3J (SSB) reception. There are a few receivers with a more straightforward approach to these functions (e.g. a mode selector and a AGC off / slow / fast selector. The R.F. and A.F. gain controls in the bottom row and the headphones jacks as well as the noise limiter switch are self explaining.
In the right lower corner of the front panel, you find the measuring instrument which will indicate the signal strength, the AF level or the temperature of the ovens 1 and 2 (should read within the green marks), just below the monitor speaker.
The main tuning knob is easily found, the green pilot lamp will indicate that manual tuning is active. When the lamp is off, the receiver is locked on a certain frequency, when the small control FEIN (fine tuning) is pulled out, the receiver provides +/- 50 Hz incremental tuning.
To operate the radio, turn it on using the main power switch, the voltage indicator should read at the line between red and white segment for mains operation and in the white segment for battery / DC operation. After 20 - 60 minutes, both ovens have reached the recommended temperature and the tuned frequency is stable within specifications.
To tune the set, select the correct frequency range and press the bpushbutton above the main tuning knob until a green light indicates that the receiver can be tuned manually. Use the main tuning knob to tune the receiver to the desired frequency, You might find the incremental tuning option useful when you try to tune in to a FSK / radioteletype signal when you need a precisely tuned signal to feed the FSK demodulator.
Use the A2/A3 mode with the small or big dot (short or long AGC time constant) for standard AM reception, you might select an I.F. bandwidth of +/- 6, +/- 3 or +/- 1.5 kHz depending on the presence of anjacent channel interference. For single sideband reception (A3J), use the upper or lower sideband 3 kHz filter and for CW (A1) reception) one of the narrow band filters. You might select manual RF gain control in one of the middle positions of the modes switch and control the RF gain manually, the volume is controlled by use of the AF gain control / NF REGELUNG. If you cannot hear anything, make sure, the set is noch in the "ON / speaker off" mode. Under special circumstances, you might lock the receiver e.g. on the frequency of a radioteletype station (press the green coloured button until the green light above the main tuning knob is OFF) and use the incremental tuning control to fine tune the receiver until the mark/space signals of a FSK signal are fed correctly to your FSK demodulator.
The receiver E 863 Kw/2 can be used together with the Telegraphiegerät TG 455 (a FSK / radioteletype demodulator), a Sichtgerät SG 455 (a CRT monitor to make mark and space signals of a FSK signal visible as an aid to tune in to a signal properly) and a Antennen - Diversitygerät AD 455 (this option is not installed with my set), with all these modules, it makes the "KW Weitverkehr Empfangsanlage TRANSRADIO 21" (Shortwave long distance communications system), there are several other modules to make the receiver fit for the reception of some very uncommon multichannel single sideband transmissions...