R1155 & T1154 Information

General Notes

The T1154/R1155 combination with all its accessories was used in many of the UK's larger aircraft during WWII, especially the Lancaster and Sunderland. The receivers in particular were a popular favourite with hams and shortwave listeners in the period following the war and are still collected by enthusiasts. Many were modified by removing the DF circuits and installing power supplies and/or an audio amplifier in their place, so those in original condition are fairly scarce. Information about these sets on the web is relatively limited. The material below helps to fill some of this gap.

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Early Technical Description
R1155 Manual Extracts
T1154 Manual Extracts
R1155 Photos
T1154 Photos
R1155 conversion for amateur use
Links to other web pages on these sets

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Technical Description of the T1154 & R1155

I have recently obtained an early official manual giving a technical description of this equipment. It is similar in style to the AP2548A familiar to most collectors but is shorter and only covers the original versions of these sets, the R1155 and the T1154 & T1154A. I assume it was the first version of what became the AP2548A. It appears to be a rare document as I can find no reference to it elsewhere on the net. For those interested, I have made a PDF copy which can be
downloaded. It is quite large at 18Mb. I would be pleased to hear from anyone who knows the RAF designation or origin of the document.

Official colour charts relating to the equipment

These charts, published as classified documents by the Air Ministry, show simplified circuits of the equipment and indicate how the various components were connected together.

Chart 1 - shows the general arrangement of the various components including the D/F equipment, antennas and power supplies.

Chart 2 - is a simplified circuit of the T1154 transmitter.

Chart 3 - gives a block diagram of the R1155 receiver

Chart 4 - contains a simplified circuit of the communications component of the R1155 and

Chart 5 - has the circuit for the Range 3 (M/F) condition whilst

Chart 6 - shows the D/F circuits.

Chart 7 - is the final diagram covering the interconnection wiring of the main components.

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R1155 - Extracts from the official manual (AP2548A)

Frequency Ranges

Switch Pos 1 L/F 1 L/F 2 L/F 2 M/F 3 M/F 3 H/F 4 H/F 5 H/F
Freq Mhz 0.075 - 0.2 0.2 - 0.5 0.2 - 0.5 0.6 - 1.5 0.6 - 1.5 1.5 - 3.0 3.0 - 7.5 7.5 - 18.5
Group 1 2 1 2 1 2 1,2 1,2

Model Types

Model Usage Freq Group Al/Fe Case Comments
1155 Air 1 Al Original model
A Air 1 Al Filters type 1
B Air 1 Al Filters type 2
C Air 1 Al As A with H/F D/F
D Air 1 Steel As R1155
E Air 1 Steel As A
F Air 1 Steel As B
L Air 2 Al Coastal Command
M Land 1 Al Land as poor quality solder
N Sea 2 Steel High Speed Launch

The extracts shown here are only a small part of the R1155 manual (AP2548A Chapter 2) but have been selected for their interest value. All have been scanned as A4 sheets.

Page 1 - is a view of the receiver from the manual.

Page 2 - gives general specifications of the R1155.

Page 3 - allows the various model types to be identified. Note that the L and N models were used for maritime work in Air Sea Rescue Launches and had different frequency ranges.

Page 4, Page 5, Page 6, Page 7 - each show part of the full circuit for models R1155, A, D, E & M.

Page 8, Page 9, Page 10 - show the index to and the 2 parts of the component location diagram.

Page 11, Page 12 Page 13 - show a typical installation diagram in an aircraft with a list of component numbers.

Page 14, Page 15 - illustrate the receiver fault finding chart which has had to be displayed as 2 pages.

Page 20, Page 21, Page 22, Page 23 - these pages list the components, showing circuit refs and their values.

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T1154 - Extracts from the official manual (AP2548A)

The extracts shown here are only a small part of the T1154 manual (AP2548A Chapter 1) but have been selected for their interest value. All have been scanned as A4 sheets.

Page 1 - gives general specifications of the T1154.

Page 2 - allows the various frequency ranges to be identified.

Page 3 - gives the main differences between the models.

Page 4 - shows the full circuit for most of the T1154 range.

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R1155 - Photo Gallery

Later knob Below are a few detailed pictures of a number of variants. The most common types seem to be the A and B variants, those used in aircraft following the addition of filters for the Irish Athlone broadcast station close to the 560KHz IF frequency and for radar frequencies. The electrical differences between the various models are due to the increasing number of filters found to be necessary and a modified frequency coverage for those used in maritime services. Cosmetic differences include the tuning knobs, use of steel or aluminium for chassis and cases and the panel lettering (painted or attached plates).

The main tuning knob was redesigned when the earlier type was found to be awkward to use, especially when the operator wore gloves against the cold, as the fine tuning section was at the rear. The redesigned knob tends to be the more common since it was retro-fitted to earlier models and is pictured at right.

Many sets are found without some of the D/F controls and most without the D/F valves, since these were both officially removed from sets not used for navigation as well as by civvy buyers to reduce the heater current.

R1155 - front panel of the rare original version without filters. Shows cloudiness of the perspex dial and discolouration of screen printed labels, both faults being quite often found. Despite some of the caps looking very tired, this set operated well as received, though a new magic eye was fitted as the original was dim. The set perfoms better than the A and B models below. The case and front have been repainted in view of the amount of missing paint and corrosion.

R1155A - front panel, with replacement improved tuning knob fitted.

R1155B - the final model. This unit has been officially rebuilt with plastic wiring for the Australian airforce in the 1950s, apparently as a "make work" job in the AWA factory. Two wiring errors, neither critical, were found plus a shorted mica cap and a VR100 with internal shorting! One wiring error was a reversed voltage divider and the other connection of the magic eye to the AF rather than the RF volume control when not on AVC. The latter was too hard to get at to fix! Now works well down to 30V on the HT!

R1155B - showing the type of mounting brackets at the rear which were used in the RAAF Lincolns. Note the safety chains to restrain the set should the rubber shockmounts come unstuck from the steel, which some of mine had! These mounts have usually been removed.

R1155E - front panel of a steel cased version.

Many additional detailed pictures of these sets, including internal views can be seen at my R1155/T1154 Gallery

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T1154 - More details and some photos

t1154b t1154m t1154l

Here are front panel views of two main variants of the transmitter. On the left are the two Bomber Command types, the T1154B & the later T1154M and on the right the High Speed Launch type, the T1154L. The main differences are in the frequency ranges of the Blue band of which the most visible sign is the Ae tuning at the top right of the L and the click mechanisms of the B (old) & M, L (new).

Frequency Ranges

Colour Yellow Blue Red Red Blue Blue Blue
Freq Mhz 0.2 - 0.5 1.5 - 3.0 2.5 - 4.5 3.0 - 5.5 4.5 - 8.7 5.5 - 10.0 8.7 - 16.7
Group 1,2,3,4 4 2,3 1,4 2,3 1 2

Model Types

Model Usage CW, MCW only Freq Group Click type Al/Fe Case Comments
1154 Air N 1 Multi Al Original model
A Air Y 1 Multi Al Original model
B Air N 1 Multi Al Halifax only
C Air N 2 Multi Al Coastal Command
D Land N 3 Multi Al Early land mobile
E Land Y 3 Multi Al Early land mobile
F Air N 2 Multi Al Superceded C
H Air N 2 Uni Al Final Coastal Command model
J Air N 1 Multi Steel Steel Bomber version
K Air N 2 Multi Steel Steel Coastal Command version
L Sea N 4 Uni Steel High Speed Launch version
M Air N 2 Uni Steel Final bomber version
N Air N 1 Uni Steel Steel version of Halifax
Multi and Uni click refer to the two types of frequency pre-setting mechanism, the latter being simpler to adjust.

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Photos of some T1154 versions

T1154B - the earlier bomber version that used the Multiclick method of frequency setting. The other two illustrated use the Uniclick method.

T1154L - the high speed launch variant covering the marine band which is quite a rare model. The main differences are in the upper right hand controls.

T1154M - the final aircraft version. This particular unit has been reconditioned for the Australian airforce in 1955 and modified to accept a 12 crystal control unit. Note top of the mounting brackets at the rear and the red slider switch to the right of the front cover which switches the crystal unit in and out.

Additional pictures of these sets, including internal views can be seen at my R1155/T1154 Gallery. Also included in the gallery are pictures of the A1134 amplifier and the full size artwork for the front panel frequency charts for the groups 1, 2, 3 & 4 above.

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Where these radios were used

Below is a picture of an ex-RAF HSL spotted on the Hamble River in the UK in 2001 and a second of the same launch taken in 2004, where the deterioration is very apparent. The first aircraft is typical Lancaster bomber which used these sets. The sets were also used in Australia and were installed in RAAF Lincolns, the second aircraft. Other aircaft using these sets were the Halifax and Sunderland. Click to enlarge these pictures.

High Speed Launch High Speed Launch
Lancaster bomber Lancaster bomber

Conversion of the R1155 to amateur use

This is an early postwar article (1946) describing the receiver and its conversion to amateur use. Essentially it gives a general explanation of its working and describes a combined mains power supply and speaker output stage used externally that you can build.There are some remarks about removal of the D/F valves and circuitry, however to do this today would greatly reduce its value to the collector.

The article consists of 5 pages Page 1, Page 2, Page 3, Page 4, Page 5 that you can view separately. They have been reduced in size to avoid excessive download times.

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R1155/T1154 - Links

These links open in a separate window.

Other Radios - If you have entered this page directly, see more stuff covering several other commercial and military sets I have described.

Duxford Radio Society's page giving a history of the development of the R1155 and T1154 by Marconi and other companies.

The No 19 Group website contains the full AP2548A official manual and detailed circuits covering both the T1154 & R1155 in PDF format. Note that these manuals have a free but rather complex password system.

The VMARS copy of the AP2548A official manual for the T1154 in PDF format. No password problem.

The VMARS copy of the AP2548A official manual for the R1155 in PDF format. No password problem.

Ray Robinson's excellent technical description of the R1155 and his efforts in restoring one.

Peter Tranter's description of the complete rebuild of an R1155. Good general description.

Another excellent description of the complete restoration of an R1155/AD8882B.

Ben Nock's web site with some contemporary pictures of the radio section of a Lancaster.

PA0PZD's good mock up of the radio and navigation sections of a Lancaster bomber including the R1155 and T1154

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Count since March 2001.
Page maintained by Simon Buxton VK2UA . Created: 13/03/01 Updated: 07/04/2013