Home

Murphy Radio, Welwyn Garden City, Hertfordsh., England

618 Admiralty Pattern 100335

Logo
travel radios
portable receivers
communication receivers
classic commercial receivers
"boatanchors"
military equipment
 
Murphy
 
Murphy B40 C
Murphy B40 D
Murphy 618
 
receiver list
receiver manuals
 

überarbeitet am 21.10.2010

Single conversion,

Analog dial,

AM, CW (SSB)

60-550 kHz, 1,5 - 30 MHz

Selectivity -6 dB
0,2 / 1 / 3 / 8 kHz

Sensitivity
 

1 fixed frequency with the use of a plug in crystal

The British maritime receiver was a successor of the legendary B40 in the end of the fifties: the typical "lighthause dial" has been replaced by a circular dial, a mechanical shutter is used to display only that part of the dial with the activated waveband.
The receiver carries the Admiralty Pattern 100335 designation, the complete set with the receiver and the matching transmitter got the designation "Murphy 618".

Murphy did stay with the typical cabinet layout of the B40, but the complete receiver is slightly smaller, it is 13 inches (33,3 cm) wide and 14 inches (36,5 cm) high. With "only" a little bit less then 30 kg, the radio is much lighter then it's predecessor.
The mains connector is the typical British screwed mains plug found on the frontpanel.
On my set, the antenna connector has been modified to a SO239 socket on the front panel.

On the front panel, You find the tuning unit with the dials, a round knob just below acts as bandswitch, a logging scale and the main tuning knob; a "heavy duty" lever is used to LOCK the tuning mechanism. Similar to the B40, the set can be used on a fixed frequency, a crystal can be fittet behind a screwed small metal cover. Just below You find the R.F. gain control.
In the bottom row of controls, You find from the left the I.F. bandwidth switch, the set gives You a good choice of narrow bandwidths with 0,2 / 1 / 3 / 8 kHz filters. Next is the mains switch, a rotary control to activate AGC, the A.F. gain / volume control and the BFO / modes switch. In position CAL, an internal calibrator gives You signals for dial calibration, in position OFF, the BFO (beat frequency oscillator) is switched off for AM reception, in position TUNE, it is active to tune in precisely on the carrier using the "zero beat" technique, BFO HIGH and LOW is used for the reception of CW or SSB reception.
Below these knobs, You find the main cable connector, sockets for two pairs of headphones and an external speaker.

The controls are still arranged in a bit a peculiar way, but operation seems to me a bit more straightforward then as with the predecessor:
Use the MAINS switch to run the set on, the BFO / modes switch is to be set to the OFF position for AM reception. Use the 8 kHz I.F. filter, select the range of the desired frequency band with range switch and search for Your 49 m band signal above the 6 MHz markings of the dial. The R.F. gain should be set to the fully clockwise position, AGC on onm use the AF gain control to adjust the volume.

The Murphy A.P. 100335 / 618 receiver is a collectors item representing the development of British marine receivers, but it is still a useful radio to listen to the signals of the major international shortwave broadcasters. It is capable of receiving some amateur radio CW and single sideband transmissions. For Your first steps into shortwave listening, I would rather recommend a portable PLL synthesized shortwave receiver like a Sony SW-7600.

 

© Martin Bösch 10.7.2010