||Type 51 HX
is an H/F transmitter consisting of transmitter 5PX and Modulator 8PX,
and aerial coil unit and a Receiver Type B11, the whole thing being rack
mounted. It is a low power ICW/CW transmitter. It can be fitted as
a L/F or H/F transmitter complete. In the former case, for use in
Tugs and Trawlers it is known as a Type 51L, but when fitted in
Destroyers, as Type 51H and will replace transmitter Type 83. "D" Class
Destroyers have been fitted with H/F transmitter 5PX and Modulator 8PX
with a separate aerial unit. In this case the complete outfit is known
as the Type 51HX [which is shown separately with its own port hole].
The modulator is fitted to produce an AF tone of 1400 c/s for keyed ICW.
Approximate range in miles = 50.
Valves of the transmitter are mounted
in "sorbo" to prevent damage to the valves due to shock. Many of
the Type 51's instruments are fully enclosed in an aluminium box. Click
on this thumbnail to read an OED [Oxford English Dictionary] definition
The Type 51 series was extensively fitted and the list of ships is
much too long to state. The variants were many. We have shown you
the Type 51, mentioned the Type 51L above, and now tell you about the
Type 51HX. Others were Types 51HV, 51FHV, 51HW, 51FHW [the Destroyer
Series]: 51LV, 51LW [Cruisers fits] but all were very similar to
the basic Type 51.