AR8-AT5 H/F M/F WWII Aircraft Radio

General Notes

These radios were roughly the Australian equivalent of the British T1154/R1155 bomber units, though they tended to be fitted to smaller aricraft such as Beaufighters, Mosquitos and Ansons and often did not require a dedicated radio operator.

As with the British equipment, the full set up comprised a number of separate units and served as crew intercom as well as a radio. The set up could operate on CW, MCW or RT and the receiver had D/F facilities on the M/F range.

The components illustrated show the AT5 transmitter on the left, the AT5 Aerial Coupling unit in the centre and the AR8 receiver on the right. The item at the top is the Artificial Aerial type A3 for tuning the equipment on the ground. The units covered M/F from 140 - 2000 khz and H/F from 2 - 20 mhz (AT5 M/F is below 500 khz). Separate tuning circuits existed in each unit for M/F and H/F so that one channel could be preset on each range and switching between them was a simple matter.

The equipment continued in use until the late 1950s, judging by the AT5Q illustrated, which has a label indicating that it was reconditioned in 1958. Valves used in the AT5 were 2 x 6V6 and 3 x 807 and in the AR8 were 6X5, 4 x 6U7, 3 x 6A8, 6J5, 6G8 and 6J7. The IF is 755 khz.

Collectability

AR8 receivers are quite common in Australia as many were converted to civilian use after the war and mated with a commercial or home brew external power supply and audio amplifier. The AT5 transmitters and ATUs can be found from time to time but power supplies and interconnecting cables are rarely seen. The radios are extremely rare outside Australia as they were seldom exported to other air forces. They are quite bulky to ship, though not unduly heavy.

These days the equipment normally comes on to the market from house clearance sales and is in "as found" condition as a result of being kept in a garage for 30 years or more rather than as restored examples. Thus quite a bit of work is often needed if they are to be made to operate again. The paper capacitors used were of poor quality and often many have deteriorated over the years.

Copies of manuals and circuits can be obtained from other collectors. Units are often missing some of the top and side panels as these are all separate pieces rather than forming a single cabinet. Wiring can be in poor condition, especially where rubber insulation has perished or been attacked by vermin.

An independent power supply is needed to run the equipment and the AR8 requires headphones. Spare knobs can be found as these were often kept when old sets were junked.

Current Condition

My equipment illustrated is electrically complete and in reasonable cosmetic condition. The AT5Q has been totally re-wired as part of the re-conditioning in 1958. I have no accessories apart from a single Junc Box socket and a few interconnect cables. Functionally my sets are "as found", though I may tackle the receiver when time permits. The receiver has headphone sockets fitted in place of the Junction Box.

The patches of light brown discolouration seen on the receiver are quite common and seem associated with the panel markings. The cause is a little unclear though I have heard that it could be associated with fingerprints of the operators or assemblers reacting with the paint used.

Type and serial numbers of my units are

Unit Type Serial # Comment

Transmitter AT5Q 8 Low serial # for Q

Ae Coupler J7732 3964 .

Receiver AR8 C7733 3013 Tuners C7747, 7748

Artificial Ae A3 Y50026 59 H/F only

The AT5 transmitter and its Aerial Coupling Unit

Count since 1/7/07.
Page maintained by Simon Buxton VK2UA Created: 17/02/02 Updated: 20/08/2007

Unit	Type	Serial #	Comment
Transmitter	AT5Q	8	Low serial # for Q
Ae Coupler	J7732	3964	.
Receiver	AR8 C7733	3013	Tuners C7747, 7748
Artificial Ae	A3 Y50026	59	H/F only