RECEIVER XCR 30,
RECEIVER OPERATING INSTRUCTIONS
General Description:
The XCR-30 is a specialised, high sensitivity portable shortwave receiver, designed to provide precision frequency
tuning over the full shortwave spectrum up to 30 MHz, with exceptional frequency stability to both amplitude
modulated (AM) and single sideband (SSB) transmissions.
The Circuit:
A multiple heterodyne circuit is incorporated wherein the harmonics of a 1 MHz quartz crystal control the frequency
shown on the dials to an accuracy sufficient to locate and identify a station whose frequency is known. The crystal
stabilises the received frequency to eliminate tuning drift over long periods of time and to provide stable single side-
band pitch. Frequency selection is a composite function of two dials. The whole number of the frequency tin MHz) is
displayed on one dial whilst the second dial displays the remaining decimal portion of the frequency.
The Aerial
A separately tuned whip antenna is provided which enables an excellent level of sensitivity for a portable receiver to be
obtained, especially at the higher frequencies where signals are usually weak.
It is also effective for medium wave frequencies, since the circuit design allows reception down to 500 kHz. However
for indoor use at this frequency, the aerial will not function as efficiently as the ferrite rod type in a conventional
medium wave portable.
ZERO SET CONTROL
This is located immediately below the signal strength meter. It provides a means of zero setting the kHz dial to
compensate for calibration errors due to temperature and/or humidity variations should this become necessary.
(1) Set mode switch to USB.
(2) Set MHz dial to any whole number.
(3) Set kHz dial to zero.
(4) Adjust zero set control to give "zero beat" in audio. That is, rotate
(5) zero set control until a whistle is heard, then adjust control to reduce the whistle to the lowest possible pitch.
Rotation of the control in either direction from this position should increase the pitch of the whistle. "Zero Beat" has
been established in this position.
