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

[Michael A. Bittner]

FWIW, During formation flying training in the mid 50s, we had VHF radios with pushbutton channel selection (I think 6 red buttons) in our SNJs. I never found out exactly what radios they were. The control box was attached just forward of the pilot's right knee on the right sidewall and so low that it was hard to see or reach. Channel selection was done prior to flight, but occasionally everyone in a formation had to switch to another channel. When this happened, heads went down in the cockpits and things became dangerous as wingmen momentarily lost sight of their leaders.  Eventually we learned to operate the pushbuttons by feel, but this is not as easy as it sounds while wearing leather flight gloves.  Later we got ARC-27s in the T-28s and TV-2s.  Rotary switch necessary here due to too many channels for dedicated pushbuttons.  This is in an era when we still had dial telephones and alphanumeric keyboards were only on mechanical typewriters.
Mike Bittner, W6MAB


----- Original Message ----- 
  From: Mike Morrow 
  To: milsurplus at mailman.qth.net ; arc5 at mailman.qth.net 
  Sent: Thursday, December 23, 2010 1:06 PM
  Subject: Re: [Milsurplus] UK-Style Pushbutton Control Boxes - Some Opinions


  John wrote:

  >You can see what channel you are on almost without actually looking at it.
  >Not so for a rotary switch. If I were flying in a dogfight, I'd strongly
  >prefer not to have to look aside, even for an instant.

  Sorry John...I've heard that before.  Also:  "It's easier to select channels
  while engaged in combat."  I believe such to be "just maybe" rationalizations
  for an irrational (or at least, very sub-optimal) design.

  A pilot would not play with radios during a heated engagement.  It's not
  likely that much channel swapping would be taking place in flight just
  before, or at the start of, or during an engagement.  I suspect that all
  aircraft in a flight about to begin combat would be on the desired command
  channel well beforehand.  If some sort of "Pipsqueak" operation was desired,
  the wiring in the SCR-522-A and the BC-608 automatically selected the
  channels of operation when the BC-608 clock was started.  No other pilot
  interaction was required there.  No similar PB system was implemented for
  the SCR-595-A Mark III or SCR-695-A Mark III/G IFF controls, which may have
  needed to be activated in emergency mode in a hurry.  These IFFs were a
  British design too...but without PBs.

  One must ask, when arguing for a purpose behind push button designs:

  (1) Why were US multi-channel MF/HF command sets (ARA/ATA, SCR-274-N, AN/ARC-9,
  RA-10DB/TA-12B, ARB/ATB, etc.) NEVER equiped with this "advantage"?
  (2) Why did the US quickly discard this feature, which was *already* in existence,
  before end of WWII for the AN/ARC-5, and before the Korean War for the AN/ARC-3.
  The SCR-522-A doubtless only retained the design due to being obsolete.
  (3) Why was such a PB design *never* used for the AN/ARC-1, AN/ARC-12, AN/ARC-27,
  or ANY other command set?  Jets fly faster and require even quicker resposes than
  WWII prop aircraft, nicht wahr?
  (4) Is it much easier to determine that a push button is depressed, as opposed
  to glancing at a selector switch?  I have all these controls, and I think it is
  not easier.  But if this were an important condition to sense visually, it could
  be more easily and effectively implemented by a larger switch pointer and scale
  on frequency select switches.

  Mike / KK5F
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