[Greg Arehart]

Not sure where to post this but....
I am thinking about instruments and looking at transponder dimensions, all except the Garmin do not appear to fit in the space behind the panel (building 9A). As I measure it, the available space (depth) is a bit over 8.5 inches, and most transponders are in the 10-inch range. What, if anything, are people doing for transponder mounting if you are using other than the Garmin? I have been considering whether to cut a hole (lighter is better....) in the bulkhead panel behind the main panel....

thanks,
greg

 

[Radomir]

You'll have to cut a hole most likely for the radio.... so depends on which equipment you end up getting, cutting a hole is normal.

 

[Greg Arehart]

Part of my concern is 1) whether a hole in the center section will in any way compromise the structural integrity of the panel (I suspect not much if at all) and 2) how accessible the back of the transponder will be for wiring etc.

greg

 

[Mark Burns]

Access panels may be the answer

Greg,

I installed access panels in the forward top skin.

See them in this thread: http://www.vansairforce.com/community/showthread.php?t=15513&highlight=access+panels

The back of the transponder will of course be easy to wire before the forward top skin is on. And with access panels like I installed you can get to them from the top later also.

Here's a shot of my forward section that will show the radio and transponder passing through the bulkhead. Well, take my word for it, the transponder is under the radio. The transponder (King KT-76A) is about an inch shorter than the Icom A-200 radio. I'm not finished wiring, it will look better!

Mark

 

[ksouthar]

Transponder Depth

You will have to cut the bulkhead to make room for the tranponder and radios (unless you use something like the MicroAire or Becker equipment).

Getting at the wiring after installation may be a challenge! I tried to plan for this by fabricating a mounting bracket behind the panel for the radio trays. That bracket is secured to the panel via screws through the front of the panel. If I need to get at the radio wiring, I pull the avionics out of the trays, remove the screws holding the bracket to the back of the panel, and drop the entire stack of trays out the bottom of the instrument panel. At least, that is the theory! I haven't had to do it yet!

Keith
RV9A Slider
N355RV

 

[Greg Arehart]

Access panel drawings

Mark,

Thanks for the photos and link. I am building a tipup, so am hoping to avoid extra access panels if possible. But... I do a fair amount of aerial photography and plan to mount a high-resolution camera in my wing, for which I will need to cut a viewport in the bottom (otherwise the camera will only get photos of the inside of the wing in the dark!). I would very much like to have your drawings as ACAD files so I can use them or modify them a bit for a polycarbonate window for my camera. My email is: arehart(at)unr.edu

Thanks!

greg