[ARC5] Unknown control box

[D C _Mac_ Macdonald]

I haven't figured it out yet, but I have a German key virtually identical to the one shown at 40 pounds Sterling.  Mine has a different knob, but it sure works nicely! 
 
The control panel looks to be a standard half-width panel; perhaps for General Aviation usage. Too bad we don't have a view of the rear where more data is likely to be discerned. 
 
The gray color of the panel almost suggests Narco which (IIRC) MAY have been the line of avionics absorbed into Cessna. I left the avionics field in late 1984 when the big oil bust virtually killed general aviation and my job along with it. 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk hotmail com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 

 
> From: tubetester at gmail.com
> Date: Wed, 16 Jul 2014 12:18:41 -0400
> To: SDAITCH at bbg.gov
> CC: arc5 at mailman.qth.net
> Subject: Re: [ARC5] Unknown control box
> 
> ​
> Here is one with more numbers on it.
> From this site about half way down.
> 
> http://morepicture.webs.com/
> 
> 
> 
> 
> $-------&
> Moe Fretz
> Collection and Preservation
> Canadian Tube Radios, Communication Equipment, Vintage Ham gear and
> Military Radios.
> Hallicrafters, RCA, National, Hammarlund,TMC, RME and Racal.
> 
> www.radiopreservationguy.com
> 
> Don't part them out ---- Restore them.
> 
> Cambridge
> Ontario Canada
> 
> 
> On Wed, Jul 16, 2014 at 7:24 AM, Sheldon Daitch <SDAITCH at bbg.gov> wrote:
> 
> >
> > Perhaps it is a prototype unit - I have no idea.  I understand the
> > ergonomics concern, but considering what appears to be the age of the unit,
> > maybe that wasn't a driving force at the time.
> >
> >
> >
> > Some semieducated guesses here.
> >
> > In many aircraft NAV/COM systems, the DME receiver is slaved off the NAV
> > radio frequency selection and there would be a need to torn the DME
> > function on or off.
> >
> > Slaving the DME transmitter/receiver off the NAV radio controller is both
> > a convenience factor and a panel space concern.  One less radio control to
> > have to deal with while in flight.
> > Most DME system frequencies are paired to VHF nav frequencies and if a DME
> > is located at a VOR facility, either VORTAC or VOR-DME, the DME system is
> > set up for that VOR frequency.  I seem to recall that some of the TACAN DME
> > frequencies can be used for DME but not all TACANs match the VHF/DME
> > frequency pairing.
> >
> > Yes, High/Low receiver sensitivity is used, as discussed below, with
> > marker beacons, but again, guessing here, I'd submit the High/low in this
> > case is the audio level from the DME receive side to the audio panel of the
> > aircraft so the pilot can monitor and verify the call sign of the DME
> > station.
> >
> > 73
> > Sheldon
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: ARC5 [mailto:arc5-bounces at mailman.qth.net] On Behalf Of D. Platt
> > Sent: Tuesday, July 15, 2014 7:57 PM
> > To: arc5 at mailman.qth.net
> > Subject: Re: [ARC5] Unknown control box
> >
> > In my humble opinion, its a control box, and probably a prototype at that.
> >  The reason I say proto is that the function switch is not human engineered
> > properly.  The knobs are way too close together and any ergo-engineer would
> > handily reject the design.  The fact that DME is even mentioned is arguably
> > for control purposes, only.  And, what does "DME off" mean?  Is it the R/T
> > unit or the audio ident? The low/stby and hi refers to what?  Selectable
> > low/high us usually relegated to the 75Mhz marker beacon receiver.  Now, it
> > may well be that the concentric freq knobs are the wrong ones.  If smaller
> > ones were used, maybe the selector switch would be OK?  Again, it screams
> > out to be a proto box as it does not comply with any standard ARINC label
> > or layout.
> >
> > Jeep - K3HVG