The R1116 Receiver

 This old receiver belonged to George Williams, a late friend of Howard James, who kindly passed on to me George's collection of radio bits and pieces together with the R1116.

 This ex-RAF superhet receiver is pretty rare nowadays and I don't know too much about it. From the valve line-up I think it must have been designed around 1933 and was probably in production up to WWII, when it was superseded by the R1155.

From the type number, and general construction, it is the same vintage as the old RAF wavemeter, the W1117

The valve line-up uses the old 2-volt British-based battery-types and these, as can be seen below, are mostly contained in metal cans.

Waveband range switching is provided by two separate, overlapping tuning dials, one for the LF ranges and the other for short-wave bands.

As the outer case is made from aluminium, I imagine that the receiver was designed for airborne use. Further clues to this is the provision of a remote volume control and a DF loop facility.

The wavebands, calibrated in Kc/s and Mc/s are as follows:-

Range 1: 142 to 315 Kc/s

Range 2: 315 to 700 Kc/s

Range 3: 700 to 1600 Kc/s

Range 4: 2 to 4.4 Mc/s

Range 5: 4.4 to 7.3 Mc/s

Range 6: 7.3 to 12.0 Mc/s

Range 7: 12.0 to 20.0 Mc/s

Ranges 1, 2 and 3 are available for DF working

 Underneath, the receiver chassis is made from steel and is nicely compartmentalised for rigidity and performance.

Two separate aerial tuners are provided and, together with the two sets of waveband switches, my guess is that this was done to give rapid switching between traffic reception and direction finding. Without this feature the operator would have had some difficulty maintaining contact with base. As can be seen, if one studies the front panel layout, there are still a number of controls to set before the two features can be selected.

You can see from the simplified circuit diagram (click the link below) that the receiver is a double superhet. I believe the first IF is around 1.7Mc/s and the second is around 100Kc/s or so.

A quaint touch is the provision for a grid bias battery near the rear of the chassis. The reason for this feature is the use of directly heated 2-volt valves. Circuits for this type of valve cannot readily cater for automatic bias and consequently, to reduce HT consumption and provide peak performance, provision has to be made to apply a negative voltage to several of the stages.

The two groups of reception bands use colour-coding, particularly reminiscent of the dials used in the later T1154 transmitter. This was probably designed to help the operator, who may have been in semi-darkness, although the layout of the controls is pretty logical.

Scale illumination is provided by small lamps fitted under the hoods over the tuning dials.

Maybe someone knows a little about the history of this receiver? I'm looking forward to working on it in the not too distant future....

Here's a simplified circuit diagram

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