[Bruce Parker (RIP)]

On no…another 19 set!!

I would like to slide a few into this series and will do my best to make sure the ones I present are interesting enough to warrant the duplication.

Canadian 19 set production began in 1942 and this set is amongst the very first off the production line. It is a Mk.II set (Canadians never made the Mk.I) made by Northern Electric. The markings on the face are black letters on white backgrounds rather than white bilingual English/Russian letters on black backgrounds therefore predating the agreement to supply Russia with 19 sets. Another early feature is that there are rubber pads in the set mounting ‘Carrier No.21’ which were later replaced with canvas ones due to wartime rubber shortages.

Specifications are similar to the set shown in Week 1, though to recap: the 19 set is a tank, ground or vehicle radio and is comprised of a long range AM ‘A’ set operating between 2 to 8 megahertz, a short range VHF ‘B’ set and an intercom (IC). Mk.II sets operated on a 12V vehicle or battery power supply and had a rotary transformer in the supply unity that provided 12, 265 and 540 volts for the sender receiver. The sender receiver was continuously tunable and required the operator to tune the frequency, an ‘A PA’ (A set, Power Amplifier) dial and an external variometer (shown in picture 4). A meter on the face could be used to check the supply unit voltages as well as ‘dip’ or reach a maximum depending on the tuning step being performed. By pushing a button on the right side of the set the operator would hear a tone when he was receiving a signal from another set allowing him to tune or ‘net’ his transmitter to the exact same frequency.

A feature of 19 sets, and one that added to its versatility, is the control systems used. On most other wireless sets headsets (or individual microphone and earphones) plugged into the radio itself or a junction box amounting to the same thing. 19 sets, alternatively, used separate control boxes that not only accommodated the headset plugs (called ‘snatch’ plugs) but allowed for easy switching between the A, B and intercom functions. Different control units allowed different access and therefore controlled who talked to whom with what radio function. Typically the senior person in a station or vehicle had the unit with the most control. The individual control units also allowed them to be placed in different locations throughout a vehicle to be near crew member positions.

Some control units had an ‘N/R’ switch (‘Normal’ and ‘Re-Broadcast’) that let the operator switch between the A, B and IC sets from the same headset. This might occur, for instance, when a tank commander talking to other tanks on the short range B set needed to quickly transmit something back to base on the A set. When switched to ‘Re-Broadcast’ the operator could be working the B set and talk on the A, be operating the A set and talk on the B or transmit on both. A pilot lamp (seen in picture 2) would go on when switched to re-broadcst operation to prevent mistaken transmissions on the wrong set.

Picture 5 is of a small folder issued to signalers with tuning and netting instructions on one side, and care and maintenance on the other.