|
In mid 1942 the Canadian Military Headquarters specified the design of a
linear RF amplifier for use with Wireless Set No.19, based on a design by
the army Engineering Design Branch (AEDB) of the development Group of
Directorate of Signal Design. In June 1942, an order for 25 units was placed
at Canadian Marcony Company, with a further 12 units to be made at the
Canadian Signals Establishment. The next year (1943) 25 Amplifiers C19* (experimental)
were dispatched to the Canadian Army Overseas in England for user tials.
Although the required ranges were obtained during field tests, it was found
that spurious radiation and harmonic interference was experienced. As this
was not acceptable , it was decided that in the meantime the Canadian Army
Overseas would equip itself with the British Amplifier RF No.2 A
later-produced filter unit known as “Gremlin Box” , connected between the
the No.19 Set and Amplifier C19* (experimental) was reported to cure the
problems of spurious radiation. In March 1943 a further order for 450 units
was placed on Rogers Majestic Limited. It was not until 1944 that the
redesigned RF amplifier, now designated Amplifier Canadian No.19, and
associated Vibrator Power Unit for use with either Wireless Set No.19 or No.22
was introduced. In contrast with the amplifier C19* (experimental) it
contained a selective internal filter which suppressed spurious RF signals
entering the amplifier.The Amplifier Canadian No.19 Amplifier Unit was
manufactured by Rogers Majestic and the Vibrator Power Unit was made by
Electronic Laboratories of Canada Ltd. The units were very similar in
apparence to the Amplifier C19* (experimental) with only slight difference
in the layout of the front panel. In 1944 field trials were undertaken to
compare the Amplifier Canadian No.19 with the British RF Amplifier No.2 The
report revealed that the Amplifier Canadian No.19 was well designed, soundly
constructed and should prove reliable in moderate temperature climates.
Under all conditions of use, the Canadian equipment gave signals one to two
R strengths better than those from the British amplifier at a given range.
The report concluded that the Canadian Amplifier was of more elaborate
design and finish, had ruggedness in every feature, but the drain on the
batteries was found mush more than imposed by the lower powered British RF
Amplifier No.2. A second disadvantage was that due to the size and weight,
the Canadian equipment was not very suitable to be removed from a vehicle
for operation as a ground station. The amplifier was not made in large
quantities, (it is beived that 500 units were produced) partly due to the
imminent end of World War II and (quoting a letter from HQ 1st Canadian Army
to CMHQ dated April1945) At this time it is thought that field formations
now have no requirements for the Amplifier Canadian No.19 . Since the
conception 3 years ago, the standards of field wireless equipment have risen.
It is unfortunate but true that the period between conception and production
in satisfactory form has been so lengthy that this equipment has become
available too late to be of any use... But in February of that year it was
already decided that the Canadian Army Overseas had no use for it and were
to dispose of the units which were held in the UK.
The Amplifier in my collection is an Amp. No.19 * (experimental) Serial
n. C 19 and the Vibrator Power Supply manifactured by Electronic
Laboratories Inc. Indianapolis, Indiana Serial 62x. |
|
|||
 |
. |
|||
|
|
||||