Swan 100MX


The Cubic Swan 100MX transceiver impresses me as the kind of radio Drake might have produced if the good folks there had made the model TR-4 all solid state.  It's a great combination of high performance and simple elegance.  This little rig is a real pleasure to use.

The PTO tuning is silky smooth, having the feel of a precision micrometer.  The analog readout is very linear and accurate to well within ±1KHz when calibrated to the nearest 25KHz calibration marker.  My particular unit reads to within ±2KHz anywhere on the dial once calibrated at the center of it's tuning range.

Another attribute is very low current draw on receive.  I measured 150 mA with the dial lamps and noise blanker turned off.  This is an advantage when operating from battery power.

The 100MX's only disappointment?  No CW filter.


Speaker/Power Supply

 General Specifications

Frequency Coverage:

Frequency Control: Stable permeability tuned oscillator (PTO), operating over the 5.0 5.5MHz range.

Modes of Operation:

  • SSB with selectable sideband.
  • CW with automatic 800Hz offset in transmit.
  • RTTY or SSTV under conditions listed in operator's manual

Power Input: 12 14 VDC negative ground only.  No damage will occur over the range of 10 to 15 VDC, although power output will be limited accordingly. 20 Amperes peak current required.

Electromagnetic Interference Reduction:  Five element low pass filter for each band.  Tuned input, tuned output RF preselector for additional selectivity.


  • Height - 3.75" 9.53cm)
  • Width - 9.75"  (24.8cm)
  • Depth - 11.60" (29.5cm)
  • Weight - 13lb (5.9kg)
Power Connector:
  • Pin 1  -  13.6 VDC (in)
  • Pin 2  -  Ground (in)
  • Pin 3  -  Ground (used for accessories)
  • Pin 4  -  13.6 VDC (in)
  • Pin 5  -  Ground (in)
  • Pin 6  -  13.6 VDC (for accessories, fused at 2A)
 Note: Due to the heavy current requirements of the 100MX, pins 1 & 4 are paralleled, as are pins 2 & 5, to reduce connector voltage drop.

Antenna Connector: UHF type SO-239

External Speaker/Phones: ¼" phone jack out to 4

External Relay: RCA jack, grounded when keyed.

External Counter: RCA jack, premixer output, level approx. 35mV RMS, frequency equals operating frequency plus 9MHz (LSB) or 9.0033MHz (USB).

Fuse:  2 Ampere fast blow, protects some internal circuitry and accessory power; external 20 ampere fast blow fuse required for full current and reverse voltage protection.


Circuit:  Single conversion to 9.00165MHz IF using  double balanced mixer, exceptional immunity to overload and cross modulation.

Sensitivity:  0.35µV for 10dB S+N/N ratio.

Selectivity:  8 pole crystal bandpass filter.  Bandwidth of 2.7KHz at 6dB points, 4.3KHz at 60dB points; 1.6 shape factor.

Internally Generated Spurious Responses:  1.0 µV or less equivalent input signal.

AGC:  6dB change in audio level over input range of 1.0µV to 0.1V (100dB)

Audio Output:  4 watts available at less than 10% distortion from 300 3000Hz into 4Ω load impedance.

Meter:  S units from 1 9 and 20, 40, 60 dB over S-9.


Circuit:   Full transceiver, solid state, with excellent harmonic and TVI suppression.  ALC limits SSB peak power and CW carrier power to 100 watts.  ALC reduces output on severe antenna mismatch to protect final devices.

Power Input:  235 watts PEP at 13.8 VDC supply.

Power Output:  100 watts PEP into 50Ω non-reactive load at 13.8 VDC supply voltage.

Unwanted Sideband Rejection:  >60dB down at 1000Hz audio frequency.

Harmonic Output:  >50dB below peak power level

Carrier Suppression:  >50dB below peak power level

Transmit Control for SSB:  PTT or VOX standard

Transmit Control for CW:  Semi break-in with standard sidetone.  Automatic 800Hz offset on transmit frequency.

Microphone Input:  25KΩ input impedance.

Audio Response: 300 - 3000Hz ±6dB

Meter:  Reads ALC voltage on transmit.

Cooling:  Large capacity finned heat sink utilized for convection cooling. For SSTV, RTTY, and semi continuous transmitting, forced air cooling supplied by a muffin type fan on heat sink is required.

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