Mount Evelyn DX Report: RETRO RECEIVER # 7: The RODHE & SCHWARZ EK 890

RETRO RECEIVER REVIEW #7

ROHDE & SCHWARZ EK 890

By Craig Seager VK2HBT

This Retro Review series normally concerns itself with the “everyman” type of receiver, but after years of driving stock-standard Fords and Toyotas, one sometimes gets a hankering for a quick spin in a Porsche, or its radio equivalent – one of the professional grade communications receivers that grace military and other government operated monitoring installations.

With new prices well out of the reach of the average hobbyist – thousands, perhaps tens of thousands of dollars – Dxers often contemplate whether the cost differential between these sets and, say, a garden variety Icom R75, is reflected in performance levels. I, for one, was determined to find out, and when a second-hand Rohde & Schwarz EK 890 became available by tender, I jumped at the chance.

The Rohde & Schwarz Company, based in Munich, is well known for a range of precision test equipment, but its communications arm has also been around for some decades, with the landmark EK 07 being released in the late 1950s. Just as England has Racal, and the United States boasts of Collins, Germany has R & S.

The half-rack width EK 890 is a digital offering, first released in 1991 and covering the full frequency range from 10 kHz – 30 mHz, with tuning and frequency display in 1 Hz increments. It comes in two basic configurations; a blind front for computer or terminal control only, or fitted with the optional GB 890 operator control panel. A single master EK 890 can be set up to control 99 slave receivers, remotely if desired. The radio is microprocessor controlled, with mode selection via layers of menus displayed on a back-lit LCD panel. Tuning is achieved by direct keypad entry or a smallish rotary encoder, with steps user programmable via “up/down” keys. The keys all have a soft and positive feel, unlike the “rubbery” recessed buttons on many modern sets.

Six filter slots are available, from 200 Hz up to 8 kHz, and all (crystal) filters can be used in each mode (AM, USB, LSB, CW, RTTY, Fax). Advanced features include passband tuning, tuneable BFO (both with on-screen display) and up to 1000 non-volatile memory channels. Scanning can be by frequency or memory channel, with hold time, dwell time and stop criteria all user programmable. There are several AGC control settings, including fast and slow attack time, and the “S” meter is a linear LCD graph calibrated in the non-standard dBuV.

BITE (Built-in Test Equipment) is a fun way to amuse a bored operator (!), and if successful results in a “Vegas” style display, with all LCD segments illuminated, followed by “BIT GO”. The diagnostic is capable of identifying faulty modules, with the “NO GO” statement coming to prominence in that eventuality. Individual clip-in modules may be replaced, but other than that I would suggest that serviceability at user level might be a bit frightening, with SMD technology employed on all of the circuit boards.

Available options include a DSP-based IF signal processor (primarily for TTY operations), a preselector module, and external speaker (there is no in-built speaker and the ¼” headphone jack also doubles as an external speaker outlet.)

Performance is quite superb, thanks largely to a superior front-end design and quality filters, with good shape factors. Strong signal performance rates well above most receivers available on the hobbyist market, with image rejection quoted at >90 dB (The Icom R75 and JRC’s NRD-535 both have image rejection at >70dB). The audio output sounds great, and readability is enhanced, particularly when ECSS and PBT are utilised. Due mostly to the small tuning increments, and inherent stability, it is very difficult to distinguish an SSB signal from standard AM.

Of course, no receiver is perfect, and improvements might include the addition of a tuneable notch filter, noise reduction, switchable preamp, clock and provision for DC operation. Of course, the EK 890 is built for a certain market, which generally has different priorities to that of the average shortwave enthusiast.

This takes us back to the original question; is it better than the Icom R75, or other contemporary fully featured sets sold to the hobbyist market? I would have to say that in terms of most basic performance criteria the answer would have to be a resounding ‘yes’, but there must be very serious doubts as to whether the EK 890 is ten or twenty times better, as the off-the-shelf price might suggest!

Key Specifications

Sensitivity
CW < 0.3 uV EMF for S/N 10dB
SSB < 1.0 uV
AM < 2.5 uV

IF Bandwidths
0.2, 0.6, 1.5, 3.1, 6, 8 kHz

Antenna Input: BNC, 50 ohm
MTBF ((mean time between failures) 14,000 hours
Dimensions 211 x 132 x 460mm
Weight 8 KG

(This article first appeared in the December 2002 issue of the the Australian DX News)

Once again, many thanks to Craig Seager for contributing this retro review to MEDXR.

NOTE: Want to learn more about this fabulous receiver? In preparing Craig's article for publication here, I came across the manufacturer's brochure on this series of receivers, called "VLF-HF Receiver Family EK890". Download it and check it out!

Missed the other Retro Reviews? Check them all out by clicking below:

Retro Receiver Review # 1 - The DANSK RX4000

Retro Receiver Review # 2 - The HITACHI KH-3800W

Retro Receiver Review # 3 - The SCHAUB LORENZ ITT TOURING T104A RECEIVER

Retro Receiver Review # 4 - The RACAL RA6790/GM

Retro Receiver Review # 5 - The REALISTIC (RADIO SHACK) DX160

Retro Receiver Review # 6 - The KENWOOD QR 666

Retro Receiver Review # 7 - The RODHE & SCHWARZ EK890

Retro Receiver Review # 8 - The YAESU FR101S

Retro Receiver Review # 9 - The SELENA VEGA B206

Retro Receiver Review # 10 - The DRAKE SPR-4

Retro Receiver Review # 11 - The NATIONAL RF-5000

Retro Receiver Review # 12 - The YAESU FRG-100

Retro Receiver Review # 13 - The MARC NR-82 F1

Retro Receiver Review # 14 - The MURPHY B40

Retro Receiver Review # 15 - The STROMBERG CARLSON AWP-8

Retro Receiver Review # 16 - The YAESU FRG-7

Retro Receiver Review # 17 - The ALLIED/REALISTIC SX-190

Retro Receiver Review # 18 - The PANASONIC RF4800/4900 (DR-48/49)

Retro Receiver Review # 19 - The ZENITH TRANSOCEANIC B600

Retro Receiver Review # 20 - The SONY ICF-5900W

Retro Receiver Review # 21 - The KENWOOD R-5000