Sense the traditional Radio rack type panel units were not an option for this installation,  we decided to go with the Becker equipment shown above.  These units offer exactly what Jeff wanted for his Stang’s #2 systems.  These remote mounted TSOd units are just the thing for the instrument panel with limited space. The remote receiver units (RT3209 Comm) and the (RN3230 Nav) are a little under 10” long  2” wide  and 6” high. Both units can fit nicely side by side in a very small remote area.  In  our case this remote area is the “Hell Hold”.  In a P51 this area is a  cavity located up from the bottom of the fuselage just in front of the tail wheel above the cooling exit door where the air exits the belly scoop.  There is approximately  2 square feet of floor space in which to mount equipment.  The control units (CU 5209 and 5301) are 2.5 “ cubed and fit into a standard 2 ¼”  instrument mounting hole.  They are actually not much larger that a panel mounted digital clock.  These control units have back lit liquid crystal displays with frequency storage and recall at the touch of a button and, of course,  Flip Flop.  The total wiring between the control head and the remote  unit consists of two twisted shielded pairs each.  These data lines contain all of the  information needed for channeling,  audio, squelch etc.  The Nav system comes in two flavors;  with Glideslope or without.  The difference is approx $800.   I highly recommend these units to all of you homebuilders and warbird refirbers.  Total cost for the two systems was just under $6000.  Not bad for a  remote mounted quality Nav and Comm system.   



The choice of what audio system to put in for me was a “No Brainer”  Not a lot has been said about these powerful little audio panels from PS engineering.  They are exactly what has been missing in the small airplane world for a long time.  Not only because they’re small and can fit in just about any instrument panel but they are also a full functioning audio panel with a state of the art ICS “Auto Vox”!  It is the same AutoVox system PS Engineering is putting in their PMA 7000 and 8000 series audiopanels.  No more fiddling around with the squelch threshold to get that just right setting which lies between having to shout to break the squelch with a complete sentence and having to listen to the aggravating ambient noise cut in and out.  This Audio panel is just what the doctor ordered.  With the capability of handling two Comms and two Navs with Transmitter selector and pilot isolation switches.  This is really all that is required for our project. The  audio from a stand alone Marker Beacon receiver *KR 22) will be piped into one of the 3 auxiliary audio inputs.  The other 2 inputs will be used for the SA 200 Altitude alerter andio that Jeff insists on and the GNS 480 warning.  Oh yes:  Jeff also wants to use one of the two entertainment inputs.  I guess a little Bach or Chopin is appropriate when your out cruising around in you P51.  I highly recommend this audio panel and have one installed in my Cessna 150. 


The Wiring Harness Takes Shape



We measured the distance from the instrument pane to the Hell Hold to be approx 15 feet.  The actual harnesss will run down the right side of the cockpit behind the circuit breaker and control panel.  The majority of the wiring to the rear will be for the compass system, gyro, Nav 2,  Remote transponder and remote Comm.  For this installation we decided to use nylon expando sleaving for the entire harness system.  This will provide anti chafing as well as make for a super “clean” installation.  When done right,  there is not a better looking or durable wiring harness installation.  It provides many benefits as well, for example, Most HSIs are front loaded into the instrument panel and in order to remove them,  its necessary to pull the instrument out of the panel far enough to disconnect the rear connector.   If the wiring harness to the HIS is tied with lacing cord or worse, held together with tie wraps., it can be very difficult trying to pull the unit far enough out to disconnect it.  The expandable sleeving by its constrictive nature holds the wires together in the bundle with little or no additional lacing.  This allows the harness to be very flexable and able to slide in and out with no restriction.    It is not for the amature install tech however.  A lot of careful planning must be done to turn out properly constructed harness.  Each length between harness break-outs must be determined,  The correct diameter size of sleaving must be used for each section of harness and the lacing



 ends must be terminated correctly.  One little item I  use to forget when doing this was remembering to slide the sleaving over the harness before terminating the connector on the end.                 

Stay tuned and you’ll see how this pile of wire finally ends up