Installing the XCom tranceiver and Microair Xponder
Posted: Thu Jan 31, 2013 3:09 pm
To All,
For what it's worth:
I decided on the XCOM and Microair products for the clean look on my panel and the features each offers. What I didn't realize is how little room there is between my instrument panel and the front pit bulkhead to install these puppies. The units fit nicely until I tried pluging in the cables to the back. I know other builders have used these radios and I followed the Makelan plans regarding measurements to a tee. I even modified the instrument panel mounting bracket to give me another inch of room. Still very tight. Too tight in fact to use the straight connectors.
The radios do fit but I had to make two parts changes. The Xponder came with an encoder and connecting cable. The cable has a straight D-sub 25 pin connector and the XCom supplies a D-Sub 15 pin "kit" which is also straight and no cable. Neither of these D-subs were going to work for me due to the lack of room behind the instrument panel. Fortunately I found a company, L-Com, that sells 90 degree D-Sub kits. I purchased one 25-pin kit and one 15-pin kit. About $10 each. The D-Sub on the transponder cable is plastic and came apart by taking the screws out of the shell. It was a simple matter to transfer the wired portion into the 90 degree housing. For the Xcom I made up my harness on the bench and installed it into the 90 degree 15-pin connector, ohmed it out and checked for ground on the shielded wires with all being well.
Again there isn't a lot of room to spare but using the 90 degree connector kits the transponder ended up with near zero clearance to the front pit bulkhead and the XCom ended up with about 1/2" clearance to the front pit bulkhead.
In summary, I wonder if other builders that installed panel mount radios and transponders had similar experiences? I'm still curious as to whether I missed something in the plans regarding the location of the front pit rear bulkhead. Any builders planning on using the panel mount radios keep in mind the 90 degree connectors that saved the day for my project.
For what it's worth:
I decided on the XCOM and Microair products for the clean look on my panel and the features each offers. What I didn't realize is how little room there is between my instrument panel and the front pit bulkhead to install these puppies. The units fit nicely until I tried pluging in the cables to the back. I know other builders have used these radios and I followed the Makelan plans regarding measurements to a tee. I even modified the instrument panel mounting bracket to give me another inch of room. Still very tight. Too tight in fact to use the straight connectors.
The radios do fit but I had to make two parts changes. The Xponder came with an encoder and connecting cable. The cable has a straight D-sub 25 pin connector and the XCom supplies a D-Sub 15 pin "kit" which is also straight and no cable. Neither of these D-subs were going to work for me due to the lack of room behind the instrument panel. Fortunately I found a company, L-Com, that sells 90 degree D-Sub kits. I purchased one 25-pin kit and one 15-pin kit. About $10 each. The D-Sub on the transponder cable is plastic and came apart by taking the screws out of the shell. It was a simple matter to transfer the wired portion into the 90 degree housing. For the Xcom I made up my harness on the bench and installed it into the 90 degree 15-pin connector, ohmed it out and checked for ground on the shielded wires with all being well.
Again there isn't a lot of room to spare but using the 90 degree connector kits the transponder ended up with near zero clearance to the front pit bulkhead and the XCom ended up with about 1/2" clearance to the front pit bulkhead.
In summary, I wonder if other builders that installed panel mount radios and transponders had similar experiences? I'm still curious as to whether I missed something in the plans regarding the location of the front pit rear bulkhead. Any builders planning on using the panel mount radios keep in mind the 90 degree connectors that saved the day for my project.