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.




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.




Marine Receiver – Skanti R5001

Dear Sparks,

under request of Radio Officer Sandro VIALE (Italy) and thanks to details supplied by him below a short review of one of the most popular marine receiver the Skanti R5001, this receiver has been produced also under Sailor and Debeg:

Frequency coverage from 10 kHz upp to 29.9999 MHz

Modes: A1, A2, A2H, A3, A3H, A3J, F1


-6 dB   -60 dB

Wide    +/- 4 kHz        +/- 17.5 kHz

Intermediate    +/- 1.2 kHz     +/- 1.9 kHz

Narrow           +/- 0.5 kHz     +/- 3.5 kHz

Very narrow    +/- 0.1 kHz     +/- 2 kHz

SSB     350 .. 2700 Hz            400 .. 3400 Hz

F1        +/- 400 Hz      +/- 850 Hz


Input High imped. values 10 dB SINAD.

Frequency       Mode Sensibility

0.1-1.6 MHz   A1       4 uV

0.1-1.6 MHz   A2, A2H, A3 18 uV

1.6-4.0 MHz   A1, A3A, A3J, F1      1 uV

1.6-4.0 MHz   A2, A2H, A3, A3H    4 uV

Input at 50Ohm, values per 10 dB SINAD.

Frequency       Mode Sensibility

0.1-1.6 MHz   A1       2 uV

0.1-1.6 MHz   A2, A2H, A3 9 uV

1.6-4.0 MHz   A1, A3A, A3J, F1      0.5 uV

1.6-4.0 MHz   A2, A2H, A3, A3H    2.5 uV

4-30 MHz       A1, A3A, A3J, F1      0.5 uV

4-30 MHz       A2, A2H, A3, A3H    2.5 uV


Headphone: 10 mW ( su 400 ohm)

Output speaker: 5 W (4 ohm)

Linea: 10 dBm (600 ohm)

Power supply

From battery: 24V

linea:110/115/120 o 220/230/240 V, 50-60 Hz

with battery 24 V circa 2 A

with the linea, about 45 VA

Bandwidth duplex filters

Band  -1 dB bandwidth

4 MHz            4355 – 4445 kHz

6 MHz            6500 – 6596 kHz

8 MHz            8710 – 8840 kHz

12 MHz          13100 – 13350 kHz

16 MHz          17230 – 17830 kHz

22 MHz          22570 – 23430 kHz

25 MHz          25300 – 26300 kHz

Dimension: 245x520x306 mm

Weight    23.6 kg




Radio room M/V Samuel L. Cobb

Dear Sparks,

below few seconds in the radio room of US M/V Samuel L. Cobb.. enjoy the video.




Marine Receiver – SAILOR R 1120

The following review and videos by Radio Officer Nino Paglialonga IZ7DJR (Italy)

Dear sparks now a real jewel :

SAILOR R1120 general coverage marine receiver made by  S.P. radio in Aalborg Denmark.

Still in production on 1987 this great receiver was quoted more than 30.000 mk on a Finnish marine products  price list ( 11.000.000  italian old “ lire “). It isn’t well known and its sizes: 12 h, 45 w, 35 d _cms. (rack system 19’’). R1120 covers 10 kHz to 30 MHz continuosly and automatically switchs 7 front-end band filters. Great RF selectivity due to a tunable preselector on the front-end acting inside each band filter. It is a double conversion receiver 1st  if =10,6085 MHz & 16,6085 MHz, 2nd if = 600 kHz, all solid state.

Other filters: 7 (seven!) xtal filters:

2 dedicated to “roofing filtering” and 5 choosen for best mode filtering.

Usb/cw/rtty (Lsb by bfo). Digital display and synth. Down to 100/Hz.

Tuning by numeric dial or continuosly by tune/knob +  unlock  button.

It is a rock: frequency drift short time= 5 Hz, long time = 25 Hz… per year!

Now my opinions:

177 pages to describe a radio receiver, but 177 seconds o so to use it.

Ergonomic commands , maximum flexibility, one knob per action.

 Noise generator for front-end peaking.

 A solid, heavy tuning knob: smooth action, nice feeling (inside: optical rotation encoder).

Great efforts spent by Danish engineers to explain everything on the  user manual.


So after years, servicing is simple using common (well chosen) electronic components.

All boards are dedicated to a single function , detailed description and two sides board drawings on the service manual.

To keep inside noise low, Danish engineers preferred to limit the synthesizer step down to 100Hz (It is a real receiver not a lab instrument).

Tuning display by green LCD .

Restful cw reading, even by  internal loudspeaker. Choosing 600 kHz if frequency, filtering is excellent, deep sides much better than common 9000 kHz filters.

Signals coming out clean, even on wide filters.

It is impressive to compare cw signals even  on  a modern ham receiver.

The ssb filter shows a 6/60 dB ratio of less than 1,6. It means that a 2350 Hz channel becomes 3700 Hz only, down 60dB.

Cw filters are superb and  the very narrow filter BW = +/-190 Hz.

Quite unusual, but useful: a page dedicated to operational tips for AGC use and another page voted to noise blanking (NB not used ! ). This is a marine oceanic receiver and have to struggle against statics expecially in tropical zones.

Last but not least:  R1120 Sailor claimes an inside TCXO at 10 MHz: excellent and  guaranteed frequency stability .

A couple of videos filmed by me iz7DJR / Nino Paglialonga



Marine Receiver – ITT Mackay 3031A

Dear Sparks,

ITT Mackay, very popular between us, produced several radio gears for Merchant Marine, on the last productions realized very fine HF receiver and one of them was the model 3031A, below the video some features, unfortunately there are not online a clip for this model but has been decided to post one video of a modern Mackay receiver (3020 model) to have an idea about the quality of these apparatus:


The 3030A is a fully synthesized, dual conversion, maritime and fixed station communications receiver.  It covers a continuous frequency range from 15 KHz to 29.99999 MHz tunable in 10 Hz increments.  Operating modes are AM, USB, RTTY, and CW (fixed, variable, and preset).

The receiver is solid state and employs modular construction. There are printed circuit boards most of which are housed in chassis mounted plug-in modules. The 3031A is capable of fully synthesized high resolution tuning of 10 Hz increments, but by using features found on the receiver, tuning of resolution finer than 5 Hz can be realized.  In addition, the 3031A is designed with 1 ppm (part per million) high stability and this gives the user a maximum potential of error reading of 30 Hz of the exact frequency of the received signal at 30 MHz.

The Mackay receivers are highly regarded for longwave tuning.  While they perform quite well on the HF bands, they were designed for maritime use which included hearing signal beacons in the longwave frequency spectrum. Few commercial receivers can equal this performance using the combination of preselector and tuning and so the Mackay receivers have a strong following for DXers who enjoy hearing signals in the longwave range.

Another unique feature of this 3031A was the selection of CW modes.  Okay, you ask, so what is the difference.

CW Fixed: Allows the operator to center the CW signal to the middle of the IF bandwidth.  This allows both the ability to zero beat the signal, but also allows for the exact identification of received frequency. Thus, this is the first step to tuning a CW signal.

CW Preset: After tuning in a signal, the operator switches to this mode to get the proper audio tone for good copy of the signal.  Thus, this is a convenient method of quickly moving from the Fixed CW to a copyable CW.  The manual directs operators to use either the .4 KHz or the 1 KHz filters for regular CW reception, but that the wider 2 and 8 KHz filters may be used to help search and locate the signals when exact CW frequency is not known.

CW Var (variable): This mode is used if the operator desires a tone that is different than the standard fixed CW tone.  In this mode, the operator would tune the BFO control to the listener preference of receiving tone. Thus, this mode of CW is typical of most receivers and is less convenient than the CW preset mode.

If you look at the mode selection knob, you will notice something unusual….there is no LSB!  This is due to the fact that since this was designated as a marine receiver, it had no need for LSB as all maritime communication is in USB.  In fact, by not having it available prevents operator error in receiving such maritime signals by inadvertently selecting the incorrect receiving mode.  However, not to worry.  CW Var mode and tuned the BFO for clarity so that getting the LSB was possible and sounds great.

Another feature that seems very unique to this 3031A receiver is the Speech Clarifier.  By pulling out this knob, the operator unlocks the synthesizer and can vary the tuned frequency. Because the receiver can tune in 10 Hz increments without the clarifier, this knob is not normally used.  But if desired or necessary, the user can literally fine tune with extreme precision.

At this point additional standard features and specs of this Mackay 3031A receiver:

  • Tuning to 10 Hz resolution
  • Selectivity of 8 / 2.0 / 1 / .4 KHz
  • AGC of fast / slow
  • RF gain
  • S /AF meter
  • Internal speaker 3.5 watts
  • Headphone / line out / speaker connections
  • Operating voltages of 90 – 130 or 195 – 260 VAC
  • Operating temp range of 5 degrees to 131 Fahrenheit (-15 to 55 centigrade)
  • Power consumption of 62 watts
  • Can sustain an input signal EMF of 30 volts for 15 minutes without damage
  • Speaker switch

The 3031A comes with a standard IEC power connector and a 3031A operation manual.




Marine Receiver – RCA AR-8516

Dear Sparks,

the United States had own factories producing famous radio gears but not devoted only for their own use, also ships or shore radio stations of foreign Countries used these equipments but not so largely than European or Japanese productions.This short review to remember the famous RCA receiver model AR-8516 both for shore or sea applications:

Producer RCA Radiomarine Products Department; Camden (NJ

Year                     1961

Tubes 18:  3BZ6 3CB6 3CB6 3BZ6 3CB6 7AU7 3CB6 3BZ6 3BZ6 3BZ6 3AL5 7AU7 5U8 3BE6 5U8 3AL5 7AU7 12CU5
Principle Supereterodyne double / triple conversion; ZF/IF 1090-3090/455/45 kHz
Bands Long waves, Medium waves, Short waves
Power Supply AC/DC 115; 230 Volt
Audio power 1 W
Model Communications Receiver AR-8516 – RCA Radiomarine Products
Materials Metal rack
Dimensions (LxHxD) 558 x 289 x 444 mm / 22 x 11.4 x 17.5 inch

RCA Radiomarine Communications Receiver AR-8516: triple conversion receiver covering 80 – 30’000 kHz in 18 continuously tuneable bands, reception modes A1 (CW), A2/A3 (AM), SSB, sensitivity above 3 kHz 2 uV AM, 1 uV CW mode. IF filter (-6/-60 dB) 6/20 kHz, 3/7 kHz, 1,5/6 kHz, 0,8/4 kHz, 0,1 kHz. Tuneable BFO in shortwave bands, noise blanker.

Triple conversion superhet, 1st IF 1090-3090 kHz (or 2000-4000 kHz) tuneable, 2nd IF 455 kHz (mechanical IF filter), 45 kHz.

Powered by 115 V DC or AC 45-65 Hz, 230 V with optional RM-288 Resistor unit, to be used from different power systems onboard ships. Accessories: RM-288 resistor unit for 230 V use, RM-289 isolation transformer 115/230V AC, RM-290 loudspeaker unit. Desktop cabinet or 19 inch relay rack. The sister model RCA Radiomarine CRM-R6A with different tube is the standard AC mains version. Of the receiver AR-8516, only one small badge is reported to be made in 1961.

Weight 41 kg / 90 lb 4.9 oz (90.308 lb)