Marine Receiver – Marconi Marine Oceanic

By Radio Officer Riccardo MEMEO (The Netherlands)

Dear Sparks,

this is a receiver produced both by Elektromekano later Danks Radio (with name M3000) and by Marconi Marine (with name “Oceanic”) I have used this radio on board bulk carrier M/V Massimiliano c/s ICZV a great receiver indeed.

On the photo below M/V Massimiliano (FERRUZZI Fleet)


In the clip below a restoring of the M3000

Technical specifications:

Coverage:  100 – 30000 kHz


Selectivity:  5.4/2.4/1/.2 kHz -6dB

Stability:  ± 1 PPM 0° to 40° C

Sensitivity:  <2 µV 4-30 MHz 20 dB

IF Rejection:  >90 dB

Image Rej.:  >90 dB

Antenna Input:  BNC 50 ohm (>4 MHz)

Audio Out:  4 W 4 ohm

Environment:  0° to +50° C

Preset freq.: 500/2182 kHz

Memories:  75

Dimensions:  509x159x463 mm weight 15 kg

Voltages:  110/220 VAC 50/60 Hz 60W or 24 VDC 85W

73’s R/O Riccardo MEMEO


6 flaws that expose the maritime sector to cyberattacks

security flaws

The maritime sector is particularly vulnerable to threats from cyberattacks on its operational technology (OT), largely because of the recent profound digital transformation it has undergone. However, exactly how vulnerable is this sector? Let’s take a closer look at the 6 main cybersecurity flaws of maritime transport.

The 6 cybersecurity flaws of maritime transport

Flaw #1: The cargo management system

The cargo management system is relying more and more on digital processes. The cargo control room and its material as well as systems for the remote control of sluice gates, for ballast water management and liquefaction of gases, all benefit from advances in digital technology. They have also inherited the flaws that come with digitization and, like all IT systems, are susceptible to cyberattacks.

Flaw #2: Navigation tools

Navigation relies on a large range of parameters, each one managed by a different system: dynamic positioning, visualization of electronic navigational charts, distress safety system (GMDSS), radars… Furthermore, unconnected gateways are vulnerable to viruses imported from peripheral storage systems such as USB falsh drives, external hard drives… A cyberattack can distort the transmission of information or render navigation tools (AIS, radar, etc.) unavailable.

Flaw #3: Control systems for the engine room

Systems managing propulsion and the operation of machines (energy control system, engine regulator, etc), the integrated control system and the alarm and emergency systems are all entry points for cyberattacks. These attacks can leave a ship stranded at sea, cause a ship to break down or even threaten its safety.

Flaw #4: Access control systems

Surveillance systems (closed-circuit television networks), bridge navigational watch alarm systems, ship security alert systems (SSAS) and even the electronic systems of on-board personnel all need to be protected and segregated in order to guarantee security. If this is not put into place, the systems could be vulnerable to attacks from ransomware (such as Petya or Wannacry) or from worms.

Flaw #5: WiFi

Public networks for passenger use (entertainment, LAN network, communications) are extremely sensitive access points. In order to guarantee the security of these systems, public networks “for enjoyment” must be 100% contained.

Flaw #6: On-board computers

On-board computers are comprised of passenger management systems, (management of goods, ship boarding access, identification systems), basic IT infrastructure (routers, firewalls, VPN, VLAN, etc.), as well as administration systems and entertainment systems for crew members. Cybersecurity on these systems must be able to prevent intrusions. These different systems must be contained.

In order to ensure the security of their networks, passengers, cargo and even the conditions of their ships, maritime companies must become aware of the flaws they are exposed to so they can implement the necessary protections. These industries must contain their different networks and equip themselves with high-performance cybersecurity systems. To provide a solution to cyber risks, the NIST standard recommends a 5-prong approach: identification of risks, protection, detection, response, and system recovery.

Source: https://www.sentryo.net on date 5 October 2017


Marine Receiver – Elektromekano M97

Review by Radio Officer Riccardo MEMEO (The Netherlands)

Dear Sparks,

an excellent Rx that I had the pleasure to use on board two ships: it is the Elektromekano M97 that can be seen on the photo of the entire RT station that I include. It was like the Siemens 745 E310 with the bandspread every 100 kHz. However, it had the advantage over the latter that the bandwidth was selectable according to the type of modulation chosen. On A1 could be selected the 300 Hz filter in case of strong qrm.

Elektromekano M97

Some features:

General coverage communications receiver, double conversion superheterodyne (single conversion below 3,7 MHz).

Range : 14 kHz to 26 MHz in 10 bands, 14-21.5 kHz; 96-230 kHz; 240-530 kHz; 600-1500 kHz; 1.5-3.8 MHz; 3.7-7.4 MHz; 7-11 MHz; 11-15 MHz; 15-19 MHz and 19-26 MHz.


Selectivity : 8.2/4/2/0.6 kHz -3 dB

Sensitivity : < 3 to 5µV 20 dB S/N (7-26 MHz)

IF Rej. : > 90 dB typical

IF : 1300-1200, 560 kHz

Image Rejection : > 65 dB

Audio out : 3.23 Ohm 1.5 W

AGC : Off/Short/Long

18 Tubes used : 2 EF85; 7 EBF80; 4 ECH81; 1 ECF 80; 1 EAA91; 1 EL95 and 2 OB2.

Calibration for bandspread every 100 kHz. (same as the Siemens E 310)

The M97 is supplied with 9 built-in crystals, plus sockets for additional 10 crystals, covering the complete  marine coastal frequencies in the 4, 6, 8, 12, 16 and 22 MHz for extra frequency stability.

Dimensions : Cabinet version 564x408x434 mm 44 Kg, 22.2x16x17” 97 Lbs

Best regards

R/O  Riccardo MEMEO



Marine Receiver – Eddystone 1830/1

By Radio Officer Sandro VIALE – Italy

Dear Sparks,

on this review it is showed the prestigious receiver 1830/1 made by Eddystone in the 70s. On many ships this receiver was dedicated as “Emergency Unit”. First time I have used this radio I was on board M/V “Jolly Marrone” c/s IBIM, below the picture of the vessel and a short clip I recovered by an old VHS cassette where the receiver is on the right side of the rack (bottom unit). After the clip are listed some features of this equipment.


Here the features of the receiver:

Year  1971–1977

Principle Superetherodyne double / triple conversion; ZF/IF 1350/100 kHz

Bands LW, MW and HF

Power supply AC 100-130 / 200-260 / Battery12 Volt

Audio power 1.5 W

Material Metal rack

Dimension (LxHxD) 502 x 164 x 376 mm / 19.8 x 6.5 x 14.8 inch

Notes General coverage receiver, covering 120 kHz – 31 MHz in 9 bands (120-250 / 240-480 / 480-950 / 920-1750 kHz, 1,5-2,9 / 2,9-5,5 / 5,5-10 / 10-19 / 18-31 MHz); AM, CW, USB/LSB.
10 crystal controlled preset channels. Optional plint loudspeaker unit 989 or cabinet speaker 935, optional anti-vibration mounting LP-2817/2. Standard production version, approved by MPT as Marine Reserve Receiver.
Also sold as S.A.I.T. MR1431 and under Hagenuk Label.

Weight 18.1 kg / 39 lb 13.9 oz (39.868 lb)

Frequency Coverage and Tuning Facilities
In the 1830/1 and 1830/2 models, a total of 9 ranges cover 120kHz to 31MHz thus:
Range          Coverage                                Conversion IF1 IF2
1.        18 to 31 MHz Double Tunable    1300-1400 kHz 100 kHz
2.        10 to 19 MHz Double Tunable    1300-1400 kHz 100 kHz
3.        5.5 to 10 MHz Double Tunable   1300-1400 kHz 100 kHz
4.        2.9 to 5 MHz Double Tunable     1300-1400 kHz 100 kHz
5.        1.5 to 2.9 MHz Double Tunable  1300-1400 kHz 100 kHz
6.        920 to 1750 kHz Single                            100 kHz
7.        480 to 950 kHz Single                              100 kHz
8.        240 to 480 kHz Single                              100 kHz
9.       120 to 250 kHz Single                               100 kHz
The 1830/3 and 1830/4 models cover similar frequencies on ranges 1 through 6 and 9, but cover the following on ranges 7 and 8, leaving a gap in the tuning range between 535kHz and 920kHz, ie. the lower half of the medium-wave or ‘Broadcast Band’:
Range           Coverage                               Conversion IF1 IF2
7.           400 to 535kHz Single                           100kHz
8.           200 to 400kHz Single                           100kHz


R/O Sandro VIALE


Marine Receiver – Eddystone 1837

Dear Sparks,

on this review some details about the marine receiver produed by Eddystone at the end of the 70s, no videos available on the web.

Country            Great Britain

Factory             Eddystone

Years                1977–1983 

Principle           Supereterodyne double / triple conversion; ZF/IF 1350/100 kHz

Bands               LW, MW, HF

Power supply   100-130; 200-260 Volts / battery 12; 24 Volts

Audio power      0.5 W

Materials            Metal rack

Dimensions (LxHxD)     483 x 133 x 334 mm / 19 x 5.2 x 13.1 inch


General coverage communication receiver covering 100 kHz – 31 MHz in nine bands AM, CW, USB/LSB, FSK optional. 840-1600 kHz segment single conversion, high stability frequency lock above 1600 kHz. Standard IF bandwidths 8/3/2,4/1,3/0,4 kHz. Digital readout 100 Hz resolution. Optional plinth speaker 989, optional panoramic unit 1061.

Weight                      16.8 kg / 37 lb 0.1 oz (37.004 lb)




Marine Receiver – RFT EKD 500

Dear Sparks,

here is a summary of the history of the East German factory RFT than one of her last receiver produced for East European market largely used in merchant marine communications:

VEB Funkwerk Dresden was a publicly owned company (VEB) in the city of Dresden during the times of the former DDR (East Germany). The company was founded under Russian occupation immediately after WWII, in 1945, and was initially known as Radio H. Mende & Co. Dresden. In 1948, it became a Volkseigener Betrieb (VEB) and was renamed to VEB Funkwerk Dresden . As the company was also part of the RFT consortium, it is also known as RFT Funwerk Dresden. Initially Funkwerk Dresden contentrated on the production of radio receivers for the domestic market, with bulk production starting in 1951. In 1962, the production of radios is cancelled and moved completely to Stern-Radio Staßfurt. From that moment on, the company concentrates on the production of measuring equipment and radio communication systems.
In 1969, Funkwerk Dresden is merged with two other VEBs, Vakutronik and Schwingungstechnik und Akustik Dresden, and moves on as VEB Meßelektronik Dresden (abbreviated as MKD).
A few years later, in 1972, the name ‘Otto Schön’ is added to the title and the company becomes known as VEB Meßelektronik ‘Otto Schön’ Dresden. This name lasts until the company is merged with the large VEB consortium Robotron in 1979, after which the name is changed to VEB Robotron-Meßelektronik ‘Otto Schön’ Dresden. On 30 June 1990, after a variety of problems in the supply chain, the company was dissolved in the light of the reunification of Germany .

Professional receiver  RTF  VEB  Funkwerk   DDR model EKD 500

10 kHz  – 30 MHz


keybord direct entry

triple PLL  synthesizer

16 selectable tuning steps

adjustable   BFO

all scan functions

filter bandwidth = 0,15/0,4/0,75/3,1/6  kHz

weight  25 Kg



The Lloyds and Maritime Communications

Dear Sparks,

from the Lloyds to Portishead Radio on the video below, enjoy our past!

Best regards,



Marine Receiver – Redifon R551N

Dear Sparks,

for long time this receiver has been employed on board merchant and passenger ships, it has been a great receiver but on the web there are not reviews and specifications, if any of you have detailed informations this article will be modified with your contribution:

This receiver was designed to a high specification and cover 10 kHz to 30 MHz with a resolution of 10 Hz, a sensitivity of 0.35 uV on the HF amateur bands and good selectivity due to 300Hz, 1 kHz and 3 kHz crystal filters.

After published this short review I received by Radio Officer Richard PHILLIPS the following message:

the  Redifon  R551N  that  you have on your site is not a commercial
radio  but one used by the British Royal Navy (and possibly other NATO
forces  too).  You  can tell this by the model number ending in N, the
NATO  spares number (5820-99-525-6189) and the fact that it is painted

The standard commercial radio is the Redifon R551. It is painted cream
and  black and does not have the ARU18 or ARU11 units.

I've  attached  a  picture  of  a  ship with a Redifon radio room that I
sailed on.
opal bounty rr




Marine Receiver – Rohde & Schwarz EK 07

Dear Sparks,

on this review it is remembered one of the Rohde & Schwarz “Excellence” the receiver model EK 07, employed in several services, it found a great place in the marine communications and it has been for several years the receiver used in Norddeich Radio and other German coast radio stations as shown in the clip below, two clips are showed, in  the second one an EK07 under tests.


Double conversion superhet, 1st I.F. 3,3 MHz, 2nd I.F. 300 kHz

Analog dial, linear, accuracy ca. 1 kHz, coverage 500 kHz – 30,1 MHz AM, CW, SSB

Selectivity -6 dB
12 / 6 / 3 / 1 / 0.2 kHz
resp. for the EK 07 D
12 / 6 / 3 / 1.5 / 0.6 / 0.3 kHz




With it’s dimensions of 54 x 33 x 55 cm (frontpanel width is a bit more then the standard 19 inch rack) and it’s weight of 66,3 kg, the Rohde & Schwarz EK 07 is not only another huge receiver, it’s bigger and heavier then the Collins R-390 or the Siemens E-311, only Telefunken’s E-104 is quite a bit bulkier and heavier… But it’s good to have two handles on each side of the cabinet, to get it lifted up on my shelves, I needed the help of my oldest son, my wife considered the thing as a bit to heavy…
The receiver can be powered from different mains voltages from 110 – 235 V and has a power consumption of 130 Watts to keep all 27 tubes glowing.

The frontpanel with the two protection handles is dominated by the very impressive 34 cm wide dial window between the two large format instruments, below the mainfrequency dial with a turret arrangement, You find the small window for the kHz indicator dial and below all other controls, the huge main tuning knob and the band selector switch activating theturret tuner arrangement.
The band selector switches the separate shortwave bands, each of them in most cases three MHz wide, in the dial window, the respective part of the shortwave dial drum will be visible.
The receiver is tuned with main tuning knob, it’s outer ring has a 30:1 gear for fine tuning, the complete tuning mechanism can be blocked mechanically.
The left measuring instrument will display the A.F. level in position “600 Ohm” and the speaker output in position “16 Ohm”. The right instrument will display the R.F. level in uV. Just next to the signal strength meter, You find a small pushbutton whick can be turned 90 dregrees when depressed to lock, it will activate the 300 kHz crystal calibrator.

The R.F. signal coming from the antenna will first have to pass an automatic preselection stage with twelve passbands and after an amplifier stage a synchroneously tunes band pass. After this, it will be mixed to a first intermediate frequency of 3,3 MHz in the ranges V – XII and then to the second i.f. of 300 kHz, below 6 MHz, the signal is directly mixed to 300 kHz as first intermediate frequency. After having passed several amplifier stages and the i.f. filters for the six bandwidths, the signal is fed to the demodulator stage after the AGC control voltage has been generated.
A diode demodulator is active for AM demodulation, for single sideband and CW operation, a BFO can be activated. There existed a mechanical remote control machine to control the EK 07 over telephone lines, control pulses did activate small motors which moved the frontpanel controls.

In practical use, the Rohde & Schwarz EK 07 is a strong competitor to other high end shortwave receivers from the sixties, it has a similar performance as the Collins R-390A, at least as fas as Am and CW reseption is concerned. Like with the Collins R-390, You need the optional single sideband demodulator for perfect single sideband demodulation, otherwise SSB performance is only fair when done with the internal BFO. But one has to remember, in most other receivers from that era, a BFO for SSB reception was all, the set did offer – Rohde & Schwarz did offer more, for another sum of money. So You could get, what money could buy in those years.
The receiver is quite resistant to overload and free of unwanted signals thanks to the automatic preselection; it has a very high stability and a very good dial accuracy with a dial resolution of better then 1 kHz.
Like with other commercial receivers from the fifties and sixties, the receiver is not equipped with the features to reject interfering signals such as a passband tuning or notch filter.