XG54 and XG54G RECEIVER SERIESSPECIFICATIONS
Types: 112-952 A-B-C-D-E and F.
Description: Single fixed frequency, crystal controlled , rack mounted , superheterodyne receiver.
Frequency range: 1620 KHz to 18 MHz in one of six predefined bands.
Modes: CW, MCW and Voice
Sensitivity: 1 microvolt for an output of 0.5 watts at a signal to signal plus noise ratio of 6 db .
Dimensions: 19 in. W x 3.5 in. H x 14 in. D
Power Consumption: 115 VAC, 25-60 Hz ; 65 watts
Weight: 17 pounds
Packaging: 19 inch rack panel mounting
Colour: Marconi Light grey
Circa: 1948 to 1952 (from drawing dates)
Instruction Manual: #590
|Aboard HMCS Stonetown. It is believed that the three receivers in the array above are Canadian Marconi type XG-54 Can anyone confirm? Please contact :firstname.lastname@example.org. (Photo source via Harold Hammerer)|
|Enlargement of the yet-to-be-confirmed XG54 receiver.|
The XG54 receiver is a single channel, crystal controlled HF receiver for general purpose use such as airport control or the the shore terminal of a ship to shore service. It is designed for rack mounting and its short panel height of 3.5 inches, allow a number of receivers to be stacked in a standard 19 inch rack. Each receiver has its own on-board 3 inch permanent magnet speaker but an external speaker can also be used.
For each of the six models, appropriate coil sets will be factory installed depending on which variant the customer ordered. The different models are summarized in the table below:
With appropriate wiring attached to the Output Plug, the following receiver functions can be remotely controlled.
a) Squelch off/on.
b) Squelch level can be varied with the use of an external rheostat.
d) Control of the transmitter associated with the receiver.
e) Switching from CW to MCW modes.
The XG54G series receivers incorporate certain modifications which enable them, when used in conjunction with remote control units such as the AG15A, to provide remote control functions not previously found in XG54 receivers.
These functions are:
a) Remote control of the BFO note
b) Remote control of RF gain.
The XG54G series also incorporates an Audio Limiter which is intended to limit the signal level fed to the line when used as a remotely operated CW receiver. A front panel switch is used to turn off the limiter when the receiver is used on MCW reception or local CW reception. In order to accomplish these additional functions, an additional tube , V13, has been added to the receiver besides certain changes to the screen resistor network associated with the RF and IF stages.
The following controls are provided: Power Off/On Switch, Volume Control, Squelch Control, RF Gain Control, CW/MCW Switch, BFO Note Control. As well, a pilot light fuse holder and 3 inch loudspeaker are mounted on the front panel .
Signal Frequency Amplifier (V1) 6BA6
Converter (V2) 6BE6
I.F. Amplifiers (V4 and V5) 6BA6
Detector (V6) 6AQ6
AVC Amplifier (V7) 6AQ6
Squelch Control and AF Amp (V10) 6SL7
AF Power Amplifier (V11) 6AK6
Bias Rectifier (V8) 6C4
Power Rectifier (V9) 6X4
Xtal Controlled Oscillator (V3) 6C4
BFO Oscillator (V12) 6BJ6
Control Tube (G series only) (V13) 6BH6
For reception of frequencies lower than 2500 KHz, the crystal frequency is 455 kHz higher than the received signal. For frequencies between 2500 KHz and 8,000 kHz, the crystal frequency is 455 kHz lower than the received signal. Above 8,000 KHz signal frequency, the crystals are used on their second harmonic and the crystal frequency will be such that twice the crystal frequency will be 455 KHz lower than the received signal .
An XG54 manual is available at the BAMA Manaul archive.
|Chassis layout pictorial. (Courtesy Canadian Marconi)|
Contributors and Credits:
1) Manual for the XG54 series receivers compliments of Gerald Caouette, VE6NAP <ve6nap(at)ve6nap.com>
2) Frank Statham
3) Tom Brent