überarbeitet am 19.4.2012
The PLL synthesized VLF - HF all wave receiver Rohde & Schwarz EK070 has been introduced in 1979. It's digital frequency readout has an accuracy of 10 Hz. The R&S EK070 has been one of the earliest shortwave receivers with direct keypad frequency entry, thirty electronic memories and the possibility of beeing remote controlled by a computer or a secondary controller BG 170.
The E-658 / Rohde & Schwarz EK 070 is a communications receiver which came in a desktop or in a 19 inch rack design, the dimensions of the rack version are 48,3 x 13,2 x 51,5 cm and it's weight 23 kg. The receiver comes with an integrated power supply and operates from 110 / 120 or 220 / 240 Volts.
The frontpanel is clearly structured:
The grey numbered pushbuttons in the right group let you select the reception frequency directly. Remember to type in leading zeros, the CLear button lets you delete wrongly entered digits, the receiver is tuned to the desired frequence after the last digit of the reception frequency has been typed in.
At the right, below the monitor speaker, you will find the volume control NF - AF and a keyboard lock button, below the mains switch the switch to activate the monitor speaker and regulate dial illumination.
Operating the receiver is very straightforward: conect to mains and a decent antenna, turn the set on with the power switch in the right upper corner and make sure, the monitor speaker is on. Select the reception mode (A1 (CW), A3E/J3E (SSB) or A3B (AM)) and the receiver will automatically switch a rexcommended I.F. bandwidth filter; select the fast AGC for Am reception, slow AGC in the other modes and tune to the desired frequency with the main tuning knob or type in the reception frequency with the numbered keys (with leading zeros for frequencies below 10 MHz), it will automatically jump to the desired frequency once you have completed entering all digits down to the 10 Hz digit.
After a switchable attenuator, the signal has to pass a low pass filter (< 500 kHz) for VLF, a band pass 500-1500 kHz for mediumwaves and a high pass filter for frequencies above 1,5 MHz. There has been an automatic eight channel suboctave frequency preselection available as an option.
The Swiss Army used the Rohde & Schwarz EK 070 with the designation E-658 with the signals intelligence, 85 receivers and 16 BG 170 controllers have been acquired. The receiving equipment has been replaced by the E-663 / Telefunken E-1800 in 2007.
© Martin Bösch 19.4.2012