Marine Receiver – ITT Mackay 3031A

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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.

73’s

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