Hammarlund Mfg. Co., New York / Mars Hill NC
HQ - 140 X
überarbeitet am 14.11.2010
The HQ-140X is a shortwave multiband receiver with bandspread dials for the amateur radio bands. It makes part of the early series of the Hammarlund shortwave receivers like the HQ-129X and the HQ-150X.
The tabletop radio is usually wired to be powered from 115 V mains, the
standard mains voltage in the U.S.A. Just make sure about the correct voltage before
You change the plug and connect the receiver to the mains outlet.
In the middle of the frontpanel, You find the two square dial windows, the
round main and bandspread frequency dials are rotated behind the fixed pointer line.
The round signal strength meter and the antenna trimmer are located in between.
On the left side of the front panel, You find the rotary controls SENSITIVITY,
corresponding to the R.F. gain control which should be set to maximum for normal operation,
and the two controls of the crystal filter, the bandwidth selector and the phasing
control to eliminate an interfering signal.
For reception of an AM signal under standard conditions, the STANDBY switch should be set
to RECEIVE, the SENSITIVITY control should be set to maximum fully clockwise, the mode
switch to AVC. For normal reception, the crystal filter can remain turned OFF. The receiver
is switched on with the AUDIO GAIN control, after a while (it takes a while until
the tubes are glowing), You hear a slight hiss in the headphones.
The antenna signal is fed via a tuned antenna circuit and a R.F. amplifier stage
(V2: 6BA6) to the mixer(V3: 6BE6), with the oscillator signal (V1: 6C4), the standard intermediate
frequency of 455 kHz is generated. After two I.F. amplifier stages (V4-6: 6BA6), the
crystal filter is switched in between them, the signal is fed to the demodulator stages.
The Hammarlund HQ-140X is a well constructed general coverage and ham band receiver, it's single conversion design is typical for the circuitry found in hollow state receivers from the early fifties. The receiver with it's "boatanchor" weight can still be used as a reliable mediumwave and amateur band radio, as long as You can do without high precision dial calibration or digital frequency readout.
© Martin Bösch 26.3.2009 / transl. 14.11.2010