[Milsurplus] UK-Style Pushbutton Control Boxes - Some Opinions

[Mike Morrow]

Andy wrote of the BC-602:

>In the Battle of Britain period, Spitfires (and, I assume, Hurricanes) were 
>fitted with the TR1133 radio. This used the same style of controller, but 
>fitted with a 12-pin oblong Jones connector. The TR1133 was then replaced 
>with the TR1143 whose controller was fited with a circular W-connector. Then 
>the SCR-522 was developed in the US to be a 'plug and play' replacement for 
>the TR1143, so also used the British W-connectors. In the RAF the SCR-522 
>became the TR5043, when they were fitted with ID plates giving both the US 
>and British Air Ministry type numbers.

Don't you wonder how these nasty push button controls ever made it to service
use?  I do.  There should have been somone in the design/manufacturing pipeline
that said "Stop...why are we proposing something so complex, when a simple rotary
switch would do?" 

I don't understand the designers' mindset for the British-style push-button
control boxes like the BC-602-A/B, the C-118/ARC-3, or the C-30/ARC-5.

Apparently better minds arrived at much simpler, much cheaper, and often
more flexible rotary-switch type controls like the C-404A/A for the AN/ARC-3
and the C-30A/ARC-5.

Compared to the later controls, the push-button boxes are orders of magnitude
more mechanically complex and thus more trouble-prone, are larger and heavier
to accomodate all that machinery, and doubtless are much more expensive to make.

In particular, the British legacy of awkward, expensive PB controls adversely
influenced the VHF SCR-274-N, and thus also the early VHF AN/ARC-5.  The
C-30/ARC-5 PB unit, after a MF/HF transmitter has been selected, leaves the
VHF receiver on the last VHF channel selected.  In contrast, the two rotory
switch design of the C-30A/ARC-5 allows selection of any R-28/ARC-5 VHF channel
(and the T-23) even after a MF/HF transmitter has been selected.  The mechanical
simplicity of the C-30A design fits in the same space as the MF/HF-only C-29
control box, and thus served as a universal-use control box in both VHF/MF/HF
installations and MF/HF-only installations.  (I suspect that's why C-29/ARC-5
control boxes are so rare...they were so unnecessary AFTER the C-30A was produced.)

I can't imagine any competent engineer coming up with the PB C-30 *before* having
arrived at the simple, capable, universal, low-cost design of the C-30A, were it
not for unfortunate British design in its history.  The same applies to the
equally nasty C-118/ARC-3.

Mike / KK5F